Ottawa, Canada

The Department of Agriculture and Agri-Food, also referred to as Agriculture and Agri-Food Canada , is the department of the government of Canada with responsibility for policies governing agriculture production, farming income, research and development, inspection, and the regulation of animals and plants. It also has responsibilities regarding rural development. It is popularly called Ag-Canada.The current Minister of Agriculture and Agri-Food is Gerry Ritz. The current Deputy Minister is Andrea Lyon. Wikipedia.

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Messiga A.J.,Agriculture and Agri Food Canada | Ziadi N.,Agriculture and Agri Food Canada | Belanger G.,Agriculture and Agri Food Canada | Morel C.,French National Institute for Agricultural Research
Nutrient Cycling in Agroecosystems | Year: 2012

Modeling changes in plant-available soil P in relation to P budgets should integrate the isotopic kinetic approach, which describes the dynamics of P ion transfer at the solid-to-solution interface. We tested a process-based mass-balance model that uses the quantity of P ions in solution, the diffusive P ions (Pr) in the solid phase, and the annual P budget to describe the soil P availability of a timothy (Phleum pratense L.) grassland that received additions of annual P and N fertilizer. An experiment was established on a gravely-sandy loam soil in 1998, with combinations of P (0, 15, 30, and 45 kg ha -1) and N (0, 60, 120, and 180 kg ha -1) applied annually from 1999 to 2006. An isotopic dilution analysis was performed on soils sampled in 2006 to calibrate the Freundlich kinetic equation which describes the dynamics of Pr transfer at the solid-to-solution interface as a function of time (t) and concentration of P ions in solution (Cp). Model simulations were performed over 9 years (1999-2007). Measurements of Cp from soils sampled between 2001 and 2007 were compared with simulated values to evaluate model performance. The amount of Pr was estimated for two transfer periods, of 2 and 3 months, to evaluate the extent and contribution of slow P ion reactions. The Freundlich kinetic equation was defined as: Pr = 7.78 × Cp 0.41 × t 0.36 (with Pr < Pr LIMIT, 192 observations, Adj. R 2 = 1.0, P < 0.001). Simulated Pr values were 74 and 84% of total inorganic soil P for the transfer periods of 2 and 3 months, respectively. For the two transfer periods, and for each combination of N and P additions, simulations accurately reflected the long-term effects of P and N fertilization on the trends of measured Cp with root mean square deviation (RMSD) between measured and simulated values of less than 0.17. Across P applications, the simulations were slightly improved with a 2-month transfer period for limiting N conditions (0 and 60 kg N ha -1; Y = 0.95X + 0.06, R 2 = 0.76, RMSD = 0.08) and a 3-month transfer period for non-limiting conditions (120 and 180 kg N ha -1; Y = 0.86X + 0.04, R 2 = 0.78, RMSD = 0.06). This approach needs to be tested in various soil types and diverse cropping systems because the estimation of Pr value can be quite sensitive to the extent of rapid and slow reactions, hence the transfer periods. For this gravely-sandy loam soil, the proposed approach accurately describes the functioning of P cycling and confirms the agronomic importance of solution and solid phase P ions in managed grasslands. © 2012 Springer Science+Business Media B.V.

Boye J.I.,Agriculture and Agri Food Canada | Roufik S.,Health Canada | Pesta N.,University of Reims Champagne Ardenne | Barbana C.,Agriculture and Agri Food Canada
LWT - Food Science and Technology | Year: 2010

Several research studies have shown that protein hydrolysates from milk and soy contain peptides that possess angiotensin I converting enzyme (ACE) inhibitory properties and may help to prevent hypertension. To date, no studies have been conducted to determine if red lentil (Lens culinaris) proteins contain peptides with ACE-inhibitory properties. The objective of the present work was to characterize the proteins present in red lentils and determine if tryptic hydrolysis could liberate peptides with ACE-inhibitory properties. Red lentil protein extracts were prepared and fractionated to obtain enriched albumin, legumin and vicilin fractions. Protein/peptide profiles were studied by electrophoresis and ACE-inhibitory activity was measured using the HPLC hippuryl-His-Leu (HHL) substrate method. Our results revealed that red lentil protein hydrolysates posses ACE-inhibitory properties. Furthermore, we demonstrated that the ACE-inhibitory property of the hydrolysates varied as a function of the protein fraction with the total lentil protein hydrolysate having the lowest half maximal inhibitory concentration (IC50) (111 ± 1 μmol/L) (i.e., highest ACE-inhibitory activity), followed by the enriched legumin (119 ± 0.5 μmol/L), albumin (127 ± 2 μmol/L) and vicilin (135 ± 2 μmol/L) fractions, respectively. Crown Copyright © 2010.

Lumba S.,University of Toronto | Toh S.,University of Toronto | Handfield L.-F.,University of Toronto | Swan M.,University of Toronto | And 8 more authors.
Developmental Cell | Year: 2014

The sesquiterpenoid abscisic acid (ABA) mediates an assortment of responses across a variety of kingdoms including both higher plants and animals. In plants, where most is known, a linear core ABA signaling pathway has been identified. However, the complexity of ABA-dependent gene expression suggests that ABA functions through an intricate network. Here, using systems biology approaches that focused on genes transcriptionally regulated by ABA, we defined an ABA signaling network of over 500 interactions among 138 proteins. This map greatly expanded ABA core signaling but was still manageable for systematic analysis. For example, functional analysis was used to identify an ABA module centered on two sucrose nonfermenting (SNF)-like kinases. We also used coexpression analysis of interacting partners within the network to uncover dynamic subnetwork structures in response to different abiotic stresses. This comprehensive ABA resource allows for application of approaches to understanding ABA functions in higher plants. © 2014 Elsevier Inc.

Suthisut D.,Agriculture and Agri Food Canada | Suthisut D.,Kasetsart University | Fields P.G.,Agriculture and Agri Food Canada | Chandrapatya A.,Kasetsart University
Journal of Stored Products Research | Year: 2011

Fumigant toxicity of essential oils from rhizomes of Alpinia conchigera, Zingiber zerumbet, Curcuma zedoaria and their major compounds; camphene, camphor, 1,8-cineole, α-humulene, isoborneol, α-pinene, β-pinene and terpinen-4-ol was investigated with adults of Sitophilus zeamais, Tribolium castaneum, Anisopteromalus calandrae and Trichogramma deion larvae. The last two insects are parasitoids commonly used to control stored-product weevils and moths. The trial was evaluated at 0, 37, 74, 148, 296, 444, 593 μL/L in air after 12, 24 and 48 h for S. zeamais, T. castaneum and A. calandrae, and 24 h for T. deion. Alpinia conchigera oils were toxic to S. zeamais, T. castaneum and T. deion, while the other two plant oils had low toxicity. Adults of S. zeamais and T. castaneum were more susceptible to A. conchigera oils than their eggs, larvae or pupae. Sitophilus zeamais adults (LC50 85 μL/L in air) were slightly more tolerant of A. conchigera oils than T. castaneum (LC50 73 μL/L in air) after 48 h exposure. Synthetic essential oils, a mixture of pure compounds in the same ratios of the extracted essential oils, were tested with S. zeamais and T. castaneum adults. Synthetic essential oils were more toxic than the extracted essential oils to both insects. Zingiber zerumbet oils (LC50 26 μL/L in air) and C. zedoaria oils (LC50 25 μL/L in air) were significantly more toxic to adults of A. calandrae than A. conchigera oils (LC50 37 μL/L in air) whereas T. deion larvae were more sensitive to A. conchigera oils (LC50 62 μL/L in air) than Z. zerumbet and C. zedoaria oils (LC50 > 593 μL/L in air). Tribolium castaneum was more susceptible than S. zeamais to the eight pure compounds. Terpinen-4-ol was highly toxic to both insects. © 2011 Elsevier Ltd.

Adam Arsovski A.,Agriculture and Agri Food Canada | Yu K.,Greenhouse and Processing Crops Research Center
Molecular Plant Pathology | Year: 2016

Rsv1, a single dominant resistance locus in soybean, confers extreme resistance to the majority of Soybean mosaic virus (SMV) strains, but is susceptible to the G7 strain. In Rsv1-genotype soybean, G7 infection provokes a lethal systemic hypersensitive response (LSHR), a delayed host defence response. The Rsv1-mediated LSHR signalling pathway remains largely unknown. In this study, we employed a genome-wide investigation to gain an insight into the molecular interplay between SMV G7 and Rsv1-genotype soybean. Small RNA (sRNA), degradome and transcriptome sequencing analyses were used to identify differentially expressed genes (DEGs) and microRNAs (DEMs) in response to G7 infection. A number of DEGs, DEMs and microRNA targets, and the interaction network of DEMs and their target mRNAs responsive to G7 infection, were identified. Knock-down of one of the identified DEGs, the eukaryotic translation initiation factor 5A (eIF5A), diminished the LSHR and enhanced viral accumulation, suggesting the essential role of eIF5A in the G7-induced, Rsv1-mediated LSHR signalling pathway. This work provides an in-depth genome-wide analysis of high-throughput sequencing data, and identifies multiple genes and microRNA signatures that are associated with the Rsv1-mediated LSHR. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Lumaret J.-P.,CNRS Center of Evolutionary and Functional Ecology | Errouissi F.,UR Biodiversite et Biologie des Populations | Floate K.,Agriculture and Agri Food Canada | Rombke J.,ECT Oekotoxikologie GmbH | Wardhaugh K.,11 Deane Street
Current Pharmaceutical Biotechnology | Year: 2012

The avermectins, milbemycins and spinosyns are collectively referred to as macrocyclic lactones (MLs) which comprise several classes of chemicals derived from cultures of soil micro-organisms. These compounds are extensively and increasingly used in veterinary medicine and agriculture. Due to their potential effects on non-target organisms, large amounts of information on their impact in the environment has been compiled in recent years, mainly caused by legal requirements related to their marketing authorization or registration. The main objective of this paper is to critically review the present knowledge about the acute and chronic ecotoxicological effects of MLs on organisms, mainly invertebrates, in the terrestrial and aquatic environment. Detailed information is presented on the mode-of-action as well as the ecotoxicity of the most important compounds representing the three groups of MLs. This information, based on more than 360 references, is mainly provided in nine tables, presenting the effects of abamectin, ivermectin, eprinomectin, doramectin, emamectin, moxidectin, and spinosad on individual species of terrestrial and aquatic invertebrates as well as plants and algae. Since dung dwelling organisms are particularly important non-targets, as they are exposed via dung from treated animals over their whole life-cycle, the information on the effects of MLs on dung communities is compiled in an additional table. The results of this review clearly demonstrate that regarding environmental impacts many macrocyclic lactones are substances of high concern particularly with larval instars of invertebrates. Recent studies have also shown that susceptibility varies with life cycle stage and impacts can be mitigated by using MLs when these stages are not present. However information on the environmental impact of the MLs is scattered across a wide range of specialised scientific journals with research focusing mainly on ivermectin and to a lesser extent on abamectin doramectin and moxidectin. By comparison, information on compounds such as eprinomectin, emamectin and selamectin is still relatively scarce. © 2012 Bentham Science Publishers.

Abbott D.W.,Agriculture and Agri Food Canada | Boraston A.B.,University of Victoria
Methods in Enzymology | Year: 2012

Carbohydrate-binding modules (CBMs) are important components of carbohydrate-active enzymes. Their primary functions are to assist in substrate turnover by targeting appended catalytic modules to substrate and concentrating appended catalytic modules on the surface of substrate. Presented here are four well-established methodologies for investigating and quantifying the CBM-polysaccharide binding relationship. These methods include: (1) the solid state depletion assay, (2) affinity gel electrophoresis, (3) UV difference and fluorescence spectroscopy, and (4) isothermal titration calorimetry. In addition, entropy-driven CBM-crystalline cellulose binding events and differential approaches to calculating stoichiometry with polyvalent polysaccharide ligands are also discussed. © 2012 Elsevier Inc. All rights reserved.

Abbott D.W.,Agriculture and Agri Food Canada | van Bueren A.L.,University of Groningen
Current Opinion in Structural Biology | Year: 2014

Generally, non-catalytic carbohydrate binding module (CBM) specificity has been shown to parallel the catalytic activity of the carbohydrate active enzyme (CAZyme) module it is appended to. With the rapid expansion in metagenomic sequence space for the potential discovery of new CBMs in addition to the recent emergence of several new CBM families that display diverse binding profiles and novel functions, elucidating the function of these protein modules has become a much more challenging task. This review summarizes several approaches that have been reported for using primary structure to inform CBM specificity and streamlining their biophysical characterization. In addition we discuss general trends in binding site architecture and several newly identified functions for CBMs. Streams of investigation that will facilitate the development and refinement of sequence-based prediction tools are suggested. © 2014.

Zifkin M.,University of Victoria | Jin A.,University of Alberta | Ozga J.A.,University of Alberta | Irina Zaharia L.,National Research Council Canada | And 6 more authors.
Plant Physiology | Year: 2012

Highbush blueberry (Vaccinium corymbosum) fruits contain substantial quantities of flavonoids, which are implicated in a wide range of health benefits. Although the flavonoid constituents of ripe blueberries are known, the molecular genetics underlying their biosynthesis, localization, and changes that occur during development have not been investigated. Two expressed sequence tag libraries from ripening blueberry fruit were constructed as a resource for gene identification and quantitative realtime reverse transcription-polymerase chain reaction primer design. Gene expression profiling by quantitative real-time reverse transcription-polymerase chain reaction showed that flavonoid biosynthetic transcript abundance followed a tightly regulated biphasic pattern, and transcript profiles were consistent with the abundance of the three major classes of flavonoids. Proanthocyanidins (PAs) and corresponding biosynthetic transcripts encoding anthocyanidin reductase and leucoanthocyanidin reductase were most concentrated in young fruit and localized predominantly to the inner fruit tissue containing the seeds and placentae. Mean PA polymer length was seven to 8.5 subunits, linked predominantly via B-type linkages, and was relatively constant throughout development. Flavonol accumulation and localization patterns were similar to those of the PAs, and the B-ring hydroxylation pattern of both was correlated with flavonoid-3'-hydroxylase transcript abundance. By contrast, anthocyanins accumulated late in maturation, which coincided with a peak in flavonoid-3-O-glycosyltransferase and flavonoid- 3'5'-hydroxylase transcripts. Transcripts of VcMYBPA1, which likely encodes an R2R3-MYB transcriptional regulator of PA synthesis, were prominent in both phases of development. Furthermore, the initiation of ripening was accompanied by a substantial rise in abscisic acid, a growth regulator that may be an important component of the ripening process and contribute to the regulation of blueberry flavonoid biosynthesis. © 2011 American Society of Plant Biologists. All Rights Reserved.

Riley R.,University of Ottawa | Charron P.,University of Ottawa | Idnurm A.,University of Missouri - Kansas City | Farinelli L.,FASTERIS S.A. | And 3 more authors.
New Phytologist | Year: 2014

Summary: Arbuscular mycorrhizal fungi (AMF) are important plant symbionts that have long been considered evolutionary anomalies because of their apparent long-term lack of sexuality, but recent explorations of available DNA sequence have challenged this notion by revealing the presence of homologues of fungal mating type-high-mobility group (MATA-HMG) and core meiotic genes in these organisms. To obtain more insights into the sexual potential of AMF, homologues of MATA-HMGs were sought in the transcriptome of three AMF isolates, and their functional and evolutionary trajectories were studied in genetically divergent strains of Rhizophagus irregularis using conventional and quantitative PCR procedures. Our analyses revealed the presence of at least 76 homologues of MATA-HMGs in R. irregularis isolates. None of these was found to be surrounded by genes generally found near other known fungal mating type loci, but here we report the presence of a 9-kb-long region in the AMF R. irregularis harbouring a total of four tandem-repeated MATA-HMGs; a feature that highlights a potentially elevated intragenomic diversity in this AMF species. The present study provides intriguing insights into the genome evolution of R. irregularis, and represents a stepping stone for understanding the potential of these fungi to undergo cryptic sex. See also the Commentary by Lee et al. © 2013 New Phytologist Trust.

Scarabaeine dung beetles are the dominant dung feeding group of insects and are widely used as model organisms in conservation, ecology and developmental biology. Due to the conflicts among 13 recently published phylogenies dealing with the higher-level relationships of dung beetles, the phylogeny of this lineage remains largely unresolved. In this study, we conduct rigorous phylogenetic analyses of dung beetles, based on an unprecedented taxon sample (110 taxa) and detailed investigation of morphology (205 characters). We provide the description of morphology and thoroughly illustrate the used characters. Along with parsimony, traditionally used in the analysis of morphological data, we also apply the Bayesian method with a novel approach that uses anatomy ontology for matrix partitioning. This approach allows for heterogeneity in evolutionary rates among characters from different anatomical regions. Anatomy ontology generates a number of parameter-partition schemes which we compare using Bayes factor. We also test the effect of inclusion of autapomorphies in the morphological analysis, which hitherto has not been examined. Generally, schemes with more parameters were favored in the Bayesian comparison suggesting that characters located on different body regions evolve at different rates and that partitioning of the data matrix using anatomy ontology is reasonable; however, trees from the parsimony and all the Bayesian analyses were quite consistent. The hypothesized phylogeny reveals many novel clades and provides additional support for some clades recovered in previous analyses. Our results provide a solid basis for a new classification of dung beetles, in which the taxonomic limits of the tribes Dichotomiini, Deltochilini and Coprini are restricted and many new tribes must be described. Based on the consistency of the phylogeny with biogeography, we speculate that dung beetles may have originated in the Mesozoic contrary to the traditional view pointing to a Cenozoic origin. © 2015 Tarasov, Génier.

Santercole V.,Porto Conte Ricerche Srl | Delmonte P.,U.S. Food and Drug Administration | Kramer J.K.G.,Agriculture and Agri Food Canada
Lipids | Year: 2012

Commercial fish oils and foods containing fish may contain trans and/or isomerized fatty acids (FA) produced during processing or as part of prepared foods. The current American Oil Chemists' Society (AOCS) official method for marine oils (method Ce 1i-07) is based on separation by use of poly(ethylene glycol) (PEG) columns, for example Supelcowax-10 or equivalent, which do not resolve most unsaturated FA geometric isomers. Highly polar 100-m cyanopropyl siloxane (CPS) columns, for example SP-2560 and CP Sil 88 are recommended for separation of geometric FA isomers. Complementary separations were achieved by use of two different elution temperature programs with the same CPS column. This study is the first direct comparison of the separations achieved by use of 30-m Supelcowax-10 and 100-m SP-2560 columns for fatty acid methyl esters (FAME) prepared from the same fish oil and fish muscle sample. To simplify the identification of the FA in these fish samples, FA were fractionated on the basis of the number and type of double bonds by silver-ion solid-phase extraction (Ag +-SPE) before GC analysis. The results showed that a combination of the three GC separations was necessary to resolve and identify most of the unsaturated FA, FA isomers, and other components of fish products, for example phytanic and phytenic acids. Equivalent chain length (ECL) values of most FAME in fish were calculated from the separations achieved by use of both GC columns; the values obtained were shown to be consistent with previously reported values for the Supelcowax-10 column. ECL values were also calculated for the FA separated on the SP-2560 column. The calculated ECL values were equally valid under isothermal and temperature-programmed elution GC conditions, and were valuable for confirmation of the identity of several unsaturated FAME in the fish samples. When analyzing commercially prepared fish foods, deodorized marine oils, or foods fortified with marine oils it is strongly recommended that quantitative data acquired by use of PEG columns is complemented with data obtained from separations using highly polar CPS columns. © AOCS 2011.

Lafontaine J.D.,Agriculture and Agri Food Canada | Schmidt B.C.,Canadian Food Inspection Agency
ZooKeys | Year: 2013

A total of 64 additions and corrections are listed and discussed for the check list of the Noctuoidea of North America north of Mexico published in 2010. One family-group name is inserted, four are changed in rank, one is deleted, one is changed in name, and three are changed in authorship. Taxo-nomic changes to species are six new or revised synonymies, one new combination, and one revision in status from species to subspecies. © J.D. Lafontaine, B.C. Schmidt.

Lafontaine J.D.,Agriculture and Agri Food Canada | Schmidt B.C.,Canadian Food Inspection Agency
ZooKeys | Year: 2013

An attempt is made to bring consensus between the classifications of the Noctuoidea in Europe and North America. Twelve points of disagreement between the check lists from the two regions are discussed and solutions recommended. © J.D. Lafontaine, B.C. Schmidt.

Quesnel H.,French National Institute for Agricultural Research | Quesnel H.,Agrocampus Ouest | Farmer C.,Agriculture and Agri Food Canada | Devillers N.,Agriculture and Agri Food Canada
Livestock Science | Year: 2012

Failure of piglets to achieve an adequate intake of colostrum is the underlying cause for the majority of piglet deaths occurring within the first days of post-natal life. From the most recent findings, it can be estimated that 200. g of colostrum per piglet during the first 24. h after birth is the minimum consumption to significantly reduce the risk of mortality before weaning, provide passive immunity and allow a slight weight gain. A consumption of 250. g could be recommended to achieve good health and pre- and post-weaning growth. On this basis, at least one-third of sows do not produce enough colostrum to fulfil the needs of their litter. Various ways to increase colostrum intake by piglets must be considered, such as increasing the ability of piglets to suckle, reducing within-litter variation in birth weight, and increasing the quantity of colostrum that sows produce. Research on sow nutrition during gestation has led to promising results, especially on piglet vitality at birth and on the acquisition of passive immunity. Approaches focusing on nutrition or genetic selection are also expected to increase litter uniformity at birth. Finally, it is evident that ways to increase sow colostrum production need to receive further attention. One area which has been neglected but which warrants more research is the potential impact of mammary development on colostrum yield. Focus in the future should be given on the impacts of sow hormonal status and nutrition during the prepuberal period and during the last days of pregnancy on the production of colostrum by sows. © 2012 Elsevier B.V.

Viaud V.,French National Institute for Agricultural Research | Angers D.A.,Agriculture and Agri Food Canada | Walter C.,Agrocampus Ouest
Soil Science Society of America Journal | Year: 2010

Because of its role in soil functioning, our ability to predict soil organic matter (SOM) dynamics, as influenced by natural and anthropogenic processes, is essential to mitigating soil degradation, ensuring (bod security, and improving the global environment. Numerous mathematical models have been developed to predict the response of SOM to agricultural practices at the soil-profile or small-plot scales. The same models, coupled with spatial databases, have been applied to larger spatial extents, especially in response to the demand for national inventories of soil C sequestration potential. Modeling SOM dynamics must also be developed at an intermediate integrative level to better investigate the relative importance of transfer and transformation processes in SOM dynamics in agricultural landscapes. Predictive models at the landscape scale will facilitate the assessment of the impact of SOM dynamics on the environment and provide management guidelines at the farm and watershed levels. We review the existing approaches and outline the various needs toward an integrated modeling of SOM at the landscape scale, Landscape-scale modeling involves specific land area representation and model requirements, which include: modeling SOM dynamics in the uncultivated elements of a landscape; simulating SOM distribution and differential dynamics along the soil profile; modeling SOM vertical and lateral fluxes linked to erosion, dissolved organic matter fluxes, and litter transfer; and modeling the spatial distribution of organic matter input and management practices. Even though progress is being made toward all of these aspects, a fully integrated framework for SOM modeling at the landscape level has still to be developed. This will only be possible with the design of a flexible, three-dimensional, spatially explicit representation of the landscape system and with the integration of functional interactions and organic matter transfer functions into the classical SOM modeling frameworks. © Soil Science Society of America, 5585 (Guiltord Rd., Madison Wl 53711 USA All rignts reserved.

Tosh S.M.,Agriculture and Agri Food Canada | Yada S.,California Almond Board
Food Research International | Year: 2010

Pulses are a good source of dietary fibre and other important nutrients. Flours and fibre-rich fractions obtained from pulse crops can be incorporated into processed foods to increase dietary fibre content and/or serve as functional ingredients. This review focuses on research conducted in the past ten years on the non-starch polysaccharides and oligosaccharides found in dry beans (Phaseolus vulgaris), chickpeas (Cicer arietinum), lentils (Lens culinaris), and dry peas (Pisum sativum). The isolation, composition, and structure of these pulse fibres are described. Common terms used to describe the physicochemical properties of fibre fractions are defined and briefly discussed. Recent studies on the effects of processing on the ratio of insoluble to soluble dietary fibre and on the α-galacto-oligosaccharide content of pulses and fibre fractions are cited and summarized. Food applications for pulse fibre fractions and flours in fibre enrichment, nutrient enrichment, fat binding and retention, and texture modification, as well as some non-food applications, are reviewed. Crown Copyright © 2009.

The fatty acid (FA) composition of longisimus dorsi (LD) and subcutaneous fat (SCF) from Rubia Gallega (RG) calves was compared for three dietary oil sources (linseed, LO; sunflower, SFO or soybean, SYO). Oils were added (4.5%) to a commercial concentrate and no differences on animal performance, carcass characteristics or meat quality among diets were noted. Total n-3 polyunsaturated FA (PUFA) increased in LD and SCF when feeding LO diet (P. <. 0.001). The trans(t) FA profiles were dominated by t11-18:1, except when feeding SFO diet, where ∑t6- to t10-18:1 exceeded t11-18:1 leading the highest (∑t6-to t10-18:1). /t11-18:11 ratio in LD (P. <. 0.05). The overall changes in n-3 PUFA and t18:1 when feeding LO and SYO could be viewed as positive for human health, but quantitatively it was apparent that most dietary PUFA were completely biohydrogenated. Inhibiting PUFA biohydrogenation will be an important next step to improve the FA composition of RG cattle. © 2013 Elsevier Ltd.

Delmonte P.,U.S. Food and Drug Administration | Fardin Kia A.-R.,U.S. Food and Drug Administration | Kramer J.K.G.,Agriculture and Agri Food Canada | Mossoba M.M.,U.S. Food and Drug Administration | And 2 more authors.
Journal of Chromatography A | Year: 2011

The ionic liquid SLB-IL111 column, available from Supelco Inc., is a novel fused capillary gas chromatography (GC) column capable of providing enhanced separations of fatty acid methyl esters (FAMEs) compared to the highly polar cyanopropyl siloxane columns currently recommended for the separation of cis- and trans isomers of fatty acids (FAs), and marketed as SP-2560 and CP-Sil 88. The SLB-IL111 column was operated isothermal at 168 °C, with hydrogen as carrier gas at 1.0. mL/min, and the elution profile was characterized using authentic GC standards and synthetic mono-unsaturated fatty acids (MUFAs) and conjugated linoleic acid (CLA) isomers as test mixtures. The SLB-IL111 column provided an improved separation of cis- and trans-18:1 and cis/. trans CLA isomers. This is the first direct GC separation of c9,. t11- from t7,. c9-CLA, and t15-18:1 from c9-18:1, both of which previously required complimentary techniques for their analysis using cyanopropyl siloxane columns. The SLB-IL111 column also provided partial resolution of t13/. t14-18:1, c8- from c6/. c7-18:1, and for several t,. t-CLA isomer pairs. This column also provided elution profiles of the geometric and positional isomers of the 16:1, 20:1 and 18:3 FAMEs that were complementary to those obtained using the cyanopropyl siloxane columns. However, on the SLB-IL111 column the saturated FAs eluted between the cis- and trans MUFAs unlike cyanopropyl siloxane columns that gave a clear separation of most saturated FAs. These differences in elution pattern can be exploited to obtain a more complete analysis of complex lipid mixtures present in ruminant fats. © 2010.

Urbez-Torres J.R.,Agriculture and Agri Food Canada | Peduto F.,University of California at Davis | Striegler R.K.,University of Missouri | Urrea-Romero K.E.,University of Arkansas | And 3 more authors.
Fungal Diversity | Year: 2012

Grapevine trunk diseases are a major concern to the wine- and table-grape industries worldwide, limiting both vineyard longevity and productivity. Field surveys conducted throughout the grape-growing regions of Arkansas and Missouri revealed the presence of three economically important grapevine trunk diseases including, Botryosphaeria canker, Eutypa dieback and esca. Morphological studies along with multi-gene phylogenetical analyses confirmed the identification of 15 different fungal taxa associated with different vascular symptoms. These include Botryosphaeria dothidea, Diatrypella sp., Diplodia seriata, Dothiorella americana, Eutypa lata, Eutypella vitis, Lasiodiplodia missouriana, Lasiodiplodia viticola, Neofusicoccum ribis, Neofusicoccum vitifusiforme, Pestalotiopsis sp., Pestalotiopsis uvicola, Phaeomoniella chlamydospora, Phomopsis viticola, Schyzophyllum commune, and Togninia minima. All of these represent new records on grapevines in Arkansas and Missouri. Dothiorella americana, L. missouriana and L. viticola are described as new species, and both N. ribis and N. vitifusiforme are first reported as grapevine pathogens in North America. Koch's postulates confirmed the pathogenicity of all fungal species except S. commune in the interspecific hybrids Vignoles, Chambourcin, Norton, and Traminette. Lasiodiplodia spp., N. ribis, and P. viticola were the most virulent fungi, while D. americana, E. vitis and N. vitifusiforme were considered to be weak pathogens. This research highlights the importance that grapevine trunk diseases have on grapevine health in growing regions where, due to different climatological conditions, interspecific hybrid cultivars are predominantly grown. © Kevin D. Hyde 2011.

Li R.,Zhejiang Academy of Agricultural Sciences | Wang X.,Zhejiang Academy of Agricultural Sciences | Zhou T.,Agriculture and Agri Food Canada | Wang Q.,University of Guelph | Zhou Y.,Zhejiang Academy of Agricultural Sciences
Food Control | Year: 2014

A total of 76 cereal and oil products collected from Yangtze Delta region of China were analyzed for occurrences of aflatoxins (AFs), aflatoxin B1 (AFB1), ochratoxin A (OTA), deoxynivalenol (DON) and zearalenone (ZEN). The mycotoxins were determined by the standard detection procedures using immunoaffinity column clean-up coupled with fluorometer (or HPLC-UV). ZEN was the most prevalent toxin, with the incidence of 27.6% (range=10.0-440.0μgkg-1), and 9.2% of the evaluated samples were contaminated with a concentration higher than that of the legislation limit of China (60μgkg-1). AFs and AFB1 were detected in 14.5% of the samples analyzed, the concentrations ranging 1.1-35.0μgkg-1 for AFs, and 1.0-32.2μgkg-1 for AFB1; 4.0% of the samples had the concentrations of AFs and AFB1 higher than that of the corresponding legislation limits of China (5.0, 10.0 and 20.0μgkg-1 for different products). OTA was detected in 14.5% of the cereal and oil products collected; the concentrations ranged 0.51-16.2μgkg-1. Only 2 samples showed OTA levels higher than that of the legislation limit of China (5.0μgkg-1). DON was detected in 7.9% of the samples; the concentrations ranged 100-700μgkg-1, and none of the samples showed DON concentration higher than that of the legislation limit of China (1.0mgkg-1). A total of 15.8% cereal and oil products were contaminated with at least two mycotoxins (multiple contaminations with different combinations including AFs-ZEN, AFs-OTA-ZEN, OTA-ZEN, ZEN-DON, OTA-ZEN-DON). The dietary exposure assessment results indicated that AFs (AFB1), OTA, DON and ZEN from cereal-based products represented a series health risk to both adults and children in Yangtze Delta region of China. This is the first report of safety evaluation associated with major mycotoxins for the area. © 2013 Elsevier Ltd.

Inderbitzin P.,University of California at Davis | Bostock R.M.,University of California at Davis | Davis R.M.,University of California at Davis | Usami T.,Chiba University | And 2 more authors.
PLoS ONE | Year: 2011

Knowledge of pathogen biology and genetic diversity is a cornerstone of effective disease management, and accurate identification of the pathogen is a foundation of pathogen biology. Species names provide an ideal framework for storage and retrieval of relevant information, a system that is contingent on a clear understanding of species boundaries and consistent species identification. Verticillium, a genus of ascomycete fungi, contains important plant pathogens whose species boundaries have been ill defined. Using phylogenetic analyses, morphological investigations and comparisons to herbarium material and the literature, we established a taxonomic framework for Verticillium comprising ten species, five of which are new to science. We used a collection of 74 isolates representing much of the diversity of Verticillium, and phylogenetic analyses based on the ribosomal internal transcribed spacer region (ITS), partial sequences of the protein coding genes actin (ACT), elongation factor 1-alpha (EF), glyceraldehyde-3-phosphate dehydrogenase (GPD) and tryptophan synthase (TS). Combined analyses of the ACT, EF, GPD and TS datasets recognized two major groups within Verticillium, Clade Flavexudans and Clade Flavnonexudans, reflecting the respective production and absence of yellow hyphal pigments. Clade Flavexudans comprised V. albo-atrum and V. tricorpus as well as the new species V. zaregamsianum, V. isaacii and V. klebahnii, of which the latter two were morphologically indistinguishable from V. tricorpus but may differ in pathogenicity. Clade Flavnonexudans comprised V. nubilum, V. dahliae and V. longisporum, as well as the two new species V. alfalfae and V. nonalfalfae, which resembled the distantly related V. albo-atrum in morphology. Apart from the diploid hybrid V. longisporum, each of the ten species corresponded to a single clade in the phylogenetic tree comprising just one ex-type strain, thereby establishing a direct link to a name tied to a herbarium specimen. A morphology-based key is provided for identification to species or species groups. © 2011 Inderbitzin et al.

Aly N.,Agriculture and Agri Food Canada | Mahmoud F.,Agriculture and Agri Food Canada
Pesticide Biochemistry and Physiology | Year: 2010

Pesticides may induce oxidative stress leading to generate free radicals and alternate antioxidant or oxygen free radical scavenging enzyme system. This study was conducted to investigate the acute toxicity of chlorpyrifos toward male mice and the oxidative stress of the sub-lethal dose (1/10 LD50) on the lipid peroxidation level (LPO), reduced glutathione content (GSH) and antioxidant enzymes; catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glucose-6-phosphate dehydrogenase (G6PD), and glutathione-S-transferase (GST) activities. Also, the protective effects of vitamin C (200 mg/kg body weight, bw) 30 min before or after administration of chlorpyrifos were investigated. The results demonstrated that the LD50 value of chlorpyrifos was 134.95 mg/kg bw. The oral administration of 13.495 mg/kg chlorpyrifos significantly caused elevation in LPO level and the activities of antioxidant enzymes including CAT, SOD and GST. However, GPx activity remained unchanged, while the level of GSH and G6PD activity were decreased. Vitamin C treatment to chlorpyrifos intoxicated mice decreased LPO level and GST activity, normalized CAT, SOD and G6PD activities, while GSH content was increased. We conclude that vitamin C significantly reduces chlorpyrifos-induced oxidative stress in mice liver and the protective effect of the pre-treatment with vitamin C is better than the post-treatment. © 2009 Elsevier Inc.

Butman D.E.,University of Washington | Wilson H.F.,Agriculture and Agri Food Canada | Barnes R.T.,Colorado College | Xenopoulos M.A.,Trent University
Nature Geoscience | Year: 2015

Approximately 8% of anthropogenic carbon dioxide emissions are estimated to come from land-use change, but this estimate excludes fluxes of terrestrial carbon to aquatic ecosystems from human disturbance. Carbon fluxes from land to rivers have probably increased by 0.1 to 0.2 petagrams of carbon per year as a result of disturbances such as deforestation, agricultural intensification and the injection of human wastewater. Most dissolved organic carbon in rivers originates from young organic carbon from soils and vegetation, but aged carbon removed from the modern carbon cycle is also exported in many systems. Here we analyse a global data set of radiocarbon ages of riverine dissolved organic carbon and spatial data on land cover, population and environmental variables. We find that the age of dissolved organic carbon in rivers increases with population density and the proportion of human-dominated landscapes within a watershed, and decreases with annual precipitation. We reason that disturbance reintroduces aged soil organic matter into the modern carbon cycle, although fossil carbon in fertilizer or petroleum products may also be a source of aged carbon in disturbed watersheds. The total export from the terrestrial environment to freshwater systems remains unknown; nevertheless, our results suggest that 3-9% of dissolved organic carbon in rivers is aged carbon mobilized by human disturbance. © 2015 Macmillan Publishers Limited. All rights reserved

Floate K.D.,Agriculture and Agri Food Canada | Kadiri N.,CNRS Center of Evolutionary and Functional Ecology
Canadian Entomologist | Year: 2013

Surveys of dung beetles establish the dominance of exotic taxa associated with cattle dung on native grasslands in southern Alberta, Canada. Of the 12 species recovered, eight were of European origin and comprised 92.2% of the total catch of 187 963 beetles. Most common were Chilothorax distinctus (Müller), Onthophagus nuchicornis (Linnaeus), and Colobopterus erraticus (Linnaeus) (Coleoptera: Scarabaeidae). The abundance of C. distinctus has been known in the region since the 1920s, whereas that of O. nuchicornis only was first reported in the 1990s. The abundance of C. erraticus has not previously been observed in the region and identifies the species as the newest addition to the endemic fauna. The diversity of native species on pastures in southern Canada and adjacent states is depauperate, such that the establishment of European taxa has appreciably increased levels of bioturbation in pasture ecosystems. The success of these exotic species on northern pastures may reflect a level of cold-tolerance greater than that of most native species. © 2013 Entomological Society of Canada.

Chiquette J.,Agriculture and Agri Food Canada | Allison M.J.,Iowa State University | Rasmussen M.,U.S. Food and Drug Administration
Journal of Dairy Science | Year: 2012

The objective of this study was to determine the efficacy of Prevotella bryantii 25A as a probiotic during a subacute ruminal acidosis (SARA) challenge using a commercial probiotic as a positive control. Six multiparous ruminally fistulated cows (BW = 685 ± 65. kg; (mean ± SD) in the mid-phase of lactation (70 to 148 DIM) received the following treatments in a replicated 3 × 3 Latin square design: (1) total mixed ration (TMR; control, CON), (2) TMR + 2. g/head per day of a probiotic combination of Enterococcus faecium and Saccharomyces cerevisiae (EFSC), or (3) TMR + Prevotella bryantii 25A. The Latin square consisted of 3. wk of adaptation to the respective treatments during which the animals were fed ad libitum once per day a conventional early-lactation TMR and 1.5. kg of hay. The adaptation was followed by 4 d of SARA (no hay) and 10. d of rest (adaptation diet without probiotics). Dry matter intake and milk production were depressed during SARA (22.0 and 31.8. kg/d, respectively) compared with adaptation (24.4 and 34.0. kg/d, respectively) and did not recover during rest (22.3 and 30.7. kg/d, respectively). During SARA, P. bryantii 25A had no effect on rumen pH, whereas EFSC reduced the percentage of time with pH <6.0 (71%) compared with CON (85%) and increased maximum pH. The EFSC treatment tended to increase mean pH over 24. h (5.65) compared with CON (5.45). Proportion of time with pH <5.6 tended to be lower with EFSC (46%) than with CON (62%). Populations of bacteria considered to be the most important cellulose digesters in the rumen (Ruminococcus flavefaciens, Ruminococcus albus, and Fibrobacter succinogenes) were also monitored during these treatments using culture-independent real-time PCR methods. The population of R. flavefaciens was similar between the 2 feeding phases, whereas F. succinogenes and R. albus were lower during SARA compared with rest. In light of the present study, P. bryantii 25A did not prove to be an effective preventative for SARA. The role of EFSC in regulating rumen pH was confirmed, with a possible effect of maintaining R. flavefaciens populations during SARA. © 2012 American Dairy Science Association.

Zhu Z.,University of Victoria | Broersma K.,Agriculture and Agri Food Canada | Mazumder A.,University of Victoria
Water, Air, and Soil Pollution | Year: 2011

A bacterial water quality model (BWQM) was developed and used to evaluate the impacts of cattle farming and climate change on the stream fecal coliform pollution in the Salmon River watershed in south-central British Columbia, Canada. The accuracy of the model simulation was evaluated using the Nash-Sutcliffe coefficient of efficiency (COE). The BWQM simulated the observed field data well, with the values of the COE ranging from 0.76 to 0.78 for the stream flow, from 0.55 to 0.60 for the fecal coliform (FC) concentration, and from 0.85 to 0.89 for the FC loading. The BWQM captured more than 79%, 66%, and 90% variation of the daily stream flow, FC concentration, and FC loading, respectively. The BWQM predicts that between 70% and 80% of the FC were transferred from the cattle farm to the Salmon River through the snowmelt-caused surface runoff during late winter and early spring, with the balance 20% to 30% coming from the soil-lateral flow and the groundwater return flow. The model also indicates that the stream FC concentration is sensitive to the distance of the cattle farm to the Salmon River. The model scenario analysis reveals that the climate change, at an assumed 1°C increment of daily air temperature, results in an increase in the stream FC concentration in the spring, fall, and winter, but there is also a decrease in the summer. The increased air temperature also changes the seasonal pattern of the stream FC concentration. Rainfall can reduce the stream FC concentration and mitigate the impact of the increased air temperature on the stream FC concentration as long as it does not result in a surface runoff or flooding event. © 2010 Springer Science+Business Media B.V.

Jovel J.,Agriculture and Agri Food Canada | Jovel J.,University of California at Riverside | Walker M.,Agriculture and Agri Food Canada | Sanfacon H.,Agriculture and Agri Food Canada
Molecular Plant-Microbe Interactions | Year: 2011

Tomato ringspot virus (ToRSV, a Nepovirus sp.) systemically infects many herbaceous plants. Viral RNA accumulates in symptomatic leaves and in young, asymptomatic leaves that emerge late in infection. Here, we show that systemic infection by ToRSV is restricted in tobacco. After an initial hypersensitive response in inoculated leaves, only a few plants showed limited systemic symptoms. Viral RNA did not usually accumulate to detectable levels in asymptomatic leaves. ToRSV-derived small-interfering RNAs and PRIa transcripts were only detected in tissues that contained viral RNA, indicating local induction of RNA silencing and salicylic acid (SA)-dependent defense responses. Lesion size and viral systemic spread were reduced with SA pretreatment but enhanced in NahG transgenic lines deficient in SA accumulation, suggesting that SA-dependent mechanisms play a key role in limiting ToRSV spread in tobacco. Restriction of virus infection was enhanced in transgenic lines expressing the P1-HC-Pro suppressor of silencing. Knocking down the SA-inducible RNA-dependent RNA polymerase 1 exacerbated the necrotic reaction but did not affect viral systemic spread. ToRSV-infected tobacco plants were susceptible to reinoculation by ToRSV or Tobacco mosaic virus, although a small reduction in lesion size was observed. This moderate systemic resistance suggests inefficient induction or spread of RNA silencing and systemic acquired resistance signal molecules.

Boraston A.B.,University of Victoria | Abbott D.W.,Agriculture and Agri Food Canada
Acta Crystallographica Section F: Structural Biology and Crystallization Communications | Year: 2012

Pectin methylesterases (PMEs) are family 8 carbohydrate esterases (CE8s) which remove the methyl group from methylesterified galacturonic acid (GalA) residues within pectin. Although the role of pectinases such as PMEs within dedicated phytopathogens has been well established, the significance of homologous enzymes found within the genomes of human enteropathogens remains to be determined. Presented here is the low-resolution (3.5 Å) structure of the CE8 from Yersinia enterocolitica (YeCE8). The high degree of structural conservation in the topology of the active-site cleft and catalytic apparatus that is shared with a characterized PME from a bacterial phytopathogen (i) indicates that YeCE8 is active on methylated pectin and (ii) highlights a more prominent role for pectin utilization in Yersinia than in other enteropathogenic species.

Soto-Cerda B.J.,Agriculture and Agri Food Canada | Soto-Cerda B.J.,Agriaquaculture Nutritional Genomic Center | Cloutier S.,Agriculture and Agri Food Canada
Plant Molecular Biology Reporter | Year: 2013

Genomic microsatellites (gSSRs) and expressed sequence tag-derived SSRs (EST-SSRs) have gained wide application for elucidating genetic diversity and population structure in plants. Both marker systems are assumed to be selectively neutral when making demographic inferences, but this assumption is rarely tested. In this study, three neutrality tests were assessed for identifying outlier loci among 150 SSRs (85 gSSRs and 65 EST-SSRs) that likely influence estimates of population structure in three differentiated flax sub-populations (F ST = 0.19). Moreover, the utility of gSSRs, EST-SSRs, and the combined sets of SSRs was also evaluated in assessing genetic diversity and population structure in flax. Six outlier loci were identified by at least two neutrality tests showing footprints of balancing selection. After removing the outlier loci, the STRUCTURE analysis and the dendrogram topology of EST-SSRs improved. Conversely, gSSRs and combined SSRs results did not change significantly, possibly as a consequence of the higher number of neutral loci assessed. Taken together, the genetic structure analyses established the superiority of gSSRs to determine the genetic relationships among flax accessions, although the combined SSRs produced the best results. Genetic diversity parameters did not differ statistically (P > 0.05) between gSSRs and EST-SSRs, an observation partially explained by the similar number of repeat motifs. Our study provides new insights into the ability of gSSRs and EST-SSRs to measure genetic diversity and structure in flax and confirms the importance of testing for the occurrence of outlier loci to properly assess natural and breeding populations, particularly in studies considering only few loci. © 2013 The Author(s).

Traugott M.,University of Innsbruck | Benefer C.M.,University of Plymouth | Blackshaw R.P.,University of Plymouth | Van Herk W.G.,Agriculture and Agri Food Canada | Vernon R.S.,Agriculture and Agri Food Canada
Annual Review of Entomology | Year: 2015

Wireworms, the larvae of click beetles (Coleoptera: Elateridae), have had a centuries-long role as major soil insect pests worldwide. With insecticidal control options dwindling, research on click beetle biology and ecology is of increasing importance in the development of new control tactics. Methodological improvements have deepened our understanding of how larvae and adults spatially and temporarily utilize agricultural habitats and interact with their environment. This progress, however, rests with a few pest species, and efforts to obtain comparable knowledge on other economically important elaterids are crucial. There are still considerable gaps in our understanding of female and larval ecology; movement of elaterids within landscapes; and the impact of natural enemies, cultivation practices, and environmental change on elaterid population dynamics. This knowledge will allow generation of multifaceted control strategies, including cultural, physical, and chemical measures, tailored toward species complexes and crops across a range of appropriate spatial scales.

Delmonte P.,U.S. Food and Drug Administration | Fardin-Kia A.R.,U.S. Food and Drug Administration | Kramer J.K.G.,Agriculture and Agri Food Canada | Mossoba M.M.,U.S. Food and Drug Administration | And 3 more authors.
Journal of Chromatography A | Year: 2012

The SLB-IL111, a new ionic liquid capillary column for gas chromatography available from Supelco Inc., was recently shown to provide enhanced separation of unsaturated geometric and positional isomers of fatty acid (FAs) when it was compared to cyanopropylsiloxane (CPS) columns currently recommended for the analysis of fatty acid methyl esters (FAMEs). A 200. m SLB-IL111 capillary column, operated under a combined temperature and eluent flow gradient, was successfully used to resolve most of the FAs contained in milk fat in a single 80. min chromatographic separation. The selected chromatographic conditions provided a balanced, simultaneous separation of short-chain (from 4:0), long-chain polyunsaturated fatty acids (PUFAs), and most of the unsaturated FA positional/geometric isomers contained in milk fat. Among the monounsaturated fatty acids (MUFAs), these conditions separated t11-18:1 and t10-18:1 FAs, the two most abundant trans fatty acids (t-FA) contained in most dairy products. These t-FAs reportedly have different biological activities. The conjugated linoleic acid (CLA) isomers commonly found in dairy products were separated from each other, including t7,. c9-18:2 from c9,. t11-18:2, which eliminated the need for their complementary silver ion HPLC analysis. The application of the SLB-IL111 column provided a complementary elution profile of FAMEs to those obtained by CPS columns, allowing for a more comprehensive FA analysis of total milk fat. The FAMEs were identified by the use of available reference materials, previously synthesized and characterized reference mixtures, and prior separations of the milk fat FAMEs by silver ion chromatography based on the number/geometry of double bonds. © 2012.

Messiga A.J.,Agriculture and Agri Food Canada | Ziadi N.,Agriculture and Agri Food Canada | Belanger G.,Agriculture and Agri Food Canada | Morel C.,French National Institute for Agricultural Research
Soil Science Society of America Journal | Year: 2013

Understanding how nutrient distribution relates to soil depth is essential for improving fertilization practices for grasslands. This study evaluated the distribution of P, other elements, and selected soil properties at 0- to 5-cm and 5- to 15-cm layers in a grass sward following several years of N and P fertilization. Soil samples were collected in the spring of 2010 from a timothy grass sward (Phleum pratense L.) established in 1998 on a gravely-sandy loam soil. Sixteen combinations of P (0, 15, 30, and 45 kg ha-1) as triple superphosphate and N (0, 60, 120, and 180 kg ha-1) as calcic ammonium nitrate were broadcast annually from 1999 to 2006 in a split-plot design with P as main plots and N as subplots. Concentration of three soil P indicators [water (CP), Mehlich-3 (PM3), and acid oxalate (POx) extractable P] and total phosphorus (PT) were greater in the 0- to 5-cm than in the 5- to 15-cm layer. Differences in concentration of CP, PM3, POx, and P T between the two soil layers increased with increasing P applications. The NH4OAc extractable Ca and Mg concentrations were significantly greater in the 0- to 5-cm soil layer compared with the 5- to 15-cm soil layer. The NH4OAc extractable K was significantly decreased by N application being greater in the 5- to 15-cm soil layer than in the 0- to 5-cm soil layer. Soil pH decreased and the concentration of Mehlich-3 Al increased with increasing N applications only in the 0- to 5-cm layer. This study demonstrated that several years of P fertilizer in grasslands could increase soil available P in the 0- to 5-cm layer, possibly due to lack of mixing and the low mobility of P. Our results also suggest that changes in soil chemical properties induced by N fertilizer in grasslands could be heightened at the 0- to 5-cm layer. Copyright © 2013 by the Soil Science Society of America, Inc.

Ziadi N.,Agriculture and Agri Food Canada | Whalen J.K.,McGill University | Messiga A.J.,Agriculture and Agri Food Canada | Morel C.,French National Institute for Agricultural Research
Advances in Agronomy | Year: 2013

Phosphorus (P) is one of the most limiting essential nutrients for agricultural crop production. Diminishing global reserves of rock phosphate are expected to reduce supply and increase the cost of mineral P fertilizers, a major concern in regions where low soil available P levels constrain crop production. In other parts of the world, intensive livestock production and agricultural management have resulted in high soil available P concentrations, which contribute to environmental pollution and threaten water quality. The objective of this review was to examine the factors affecting soil available P in agroecosystems. Physicochemical and biological controls on the soil available P, in the context of P biogeochemical cycling, are presented. Agricultural management practices such as crop rotations, tillage, and P fertilizer sources influence the size of the soil available P pool, while environmental conditions such as freezing-thawing and wetting-drying cycles control the temporal dynamics of this pool. Methods to evaluate soil available P in the laboratory and in situ are reviewed. Attention is given to the isotopic dilution method that quantifies fluxes of P ions between soil solid phase and soil solution, which can be combined with the Freundlich kinetic equation to describe diffusive soil P transfer, leading to the development of a process-based mass-balance model to assess soil available P. This model has potential to advance scientific understanding about soil available P dynamics for better decision making about P fertilization and agroenvironmental management in sustainable cropping systems. © 2013 Elsevier Inc.

Champagne C.P.,Agriculture and Agri Food Canada | Tompkins T.A.,Lallemand Inc. | Buckley N.D.,Canadian Space Agency | Green-Johnson J.M.,University of Ontario Institute of Technology
Food Microbiology | Year: 2010

Enhancement of nutritional or vitamin content of foods is commonly touted as a major benefit of probiotics. In this paper, we examined the ability of three probiotic bacteria either alone or in combination to enhance nutritional content. Pure and mixed cultures of Streptococcus thermophilus ST5 and Lactobacillus helveticus R0052 or Bifidobacterium longum R0175 were used to prepare fermented soy beverages. The effects of strain, acidification and mixed cultures on the deconjugation of soy isoflavones were examined. Acidification to pH 4.7 alone resulted in a 7% drop in isoflavone levels. Deconjugation levels varied between the different glucosides. Fermentation by L. helveticus R0052 resulted in the 50% reduction in total glucosides with O-malonyl glucosides being reduced 64%. Fermentation by S. thermophilus ST5 or B. longum R0175 had no significant effect on isoflavone levels. Combining a S. thermophilus strain with a L. helveticus culture reduced the effectiveness of the latter. Fermentation did not significantly modify vitamin B1 or B6 levels. © 2010.

Pitt W.M.,Charles Sturt University | Urbez-Torres J.R.,Agriculture and Agri Food Canada | Trouillas F.P.,University of California at Davis
Fungal Diversity | Year: 2013

Strains of a coelomycete isolated from grapevine cankers in southeastern Australia and identified as Dothiorella iberica in previous studies are redescribed in this study as a novel species based on morphological characters and phylogenetic analyses of DNA sequences of the internal transcribed spacer region (ITS1-5.8S-ITS2), and partial sequences of the translation elongation factor 1-α and β-tubulin genes. Dothiorella vidmadera sp. nov. is most closely related to D. iberica, D. americana and D. sarmentorum, but differs in morphological characters and DNA sequences. All four species are known to be associated with Botryosphaeria dieback of grapevines. Additionally, an unidentified ascomycete isolated from dead wood of grapevines in Western Australia is described. Phylogenetically, strains were most closely related to Spencermartinsia viticola, and bore conidia with morphological characters and dimensions consistent with published descriptions. However, ascospores were shorter and narrower than previously reported and lacked the terminal apiculi that typify the genus. © 2013 Mushroom Research Foundation.

Suthisut D.,Agriculture and Agri Food Canada | Suthisut D.,Kasetsart University | Fields P.G.,Agriculture and Agri Food Canada | Chandrapatya A.,Kasetsart University
Journal of Economic Entomology | Year: 2011

The essential oils from rhizomes of Alpinia conchigera Griff, Zingiber zerumbet Smitt, Curcuma zedoaria (Berg.) Roscoe; their major compounds (camphene, camphor, 1,8-cineole, α-humulene, isoborneol, α-pinene, β-pinene and terpinen-4-ol); and synthetic essential oils comprised of mixtures of major pure compounds in the same ratios as the extracted essential oils were tested for contact, feeding reduction, and repellency against Sitophilus zeamais Motschulsky and Tribolium castaneum (Herbst) adults. Via topical applications, the three extracted oils had similar toxicity against S. zeamais (LD50, fiducial limits: 18-24 μg oil/mg insect). T. castaneum had similar sensitivity to all three oils (35-58 μg/mg), and it was less sensitive than S. zeamais. The LD50 values of synthetic A. conchigera and synthetic Z. zerumbet oils were similar to those of their corresponding extracted essential oils. The synthetic C. zedoaria oils showed lower contact toxicity than the extracted C. zedoaria oils to both insects. Sitophilus zeamais and T. castaneum were sensitive to terpinen-4-ol and isoborneol in contact toxicity tests. In antifeedant tests, the three extracted oils were able to decrease the consumption of flour disks, especially Z. zerumbet oils, whereas both insect species could feed on the flour disks treated with three synthetic essential oils. Only terpinen-4-ol deterred feeding in both insects. In repellency tests, A. conchigera oils at highest concentration repelled S. zeamais and T. castaneum. None of the synthetic essential oils repelled S. zeamais (315 μl/cm 2) and T. castaneum (31 μl/cm 2). Only terpinen-4-ol showed repellent activity against both insects. © 2011 Entomological Society of America.

Abdeen A.,Agriculture and Agri Food Canada | Abdeen A.,McGill University | Schnell J.,Agriculture and Agri Food Canada | Schnell J.,Canadian Food Inspection Agency | Miki B.,Agriculture and Agri Food Canada
BMC Genomics | Year: 2010

Background: Plants engineered for abiotic stress tolerance may soon be commercialized. The engineering of these plants typically involves the manipulation of complex multigene networks and may therefore have a greater potential to introduce pleiotropic effects than the simple monogenic traits that currently dominate the plant biotechnology market. While research on unintended effects in transgenic plant systems has been instrumental in demonstrating the substantial equivalence of many transgenic plant systems, it is essential that such analyses be extended to transgenic plants engineered for stress tolerance. Drought-tolerant Arabidopsis thaliana were engineered through overexpression of the transcription factor ABF3 in order to investigate unintended pleiotropic effects. In order to eliminate position effects, the Cre/lox recombination system was used to create control plant lines that contain identical T-DNA insertion sites but with the ABF3 transgene excised. This additionally allowed us to determine if Cre recombinase can cause unintended effects that impact the transcriptome.Results: Microarray analysis of control plant lines that underwent Cre-mediated excision of the ABF3 transgene revealed only two genes that were differentially expressed in more than one plant line, suggesting that the impact of Cre recombinase on the transcriptome was minimal. In the absence of drought stress, overexpression of ABF3 had no effect on the transcriptome, but following drought stress, differences were observed in the gene expression patterns of plants overexpressing ABF3 relative to control plants. Examination of the functional distribution of the differentially expressed genes revealed strong similarity indicating that unintended pathways were not activated.Conclusions: The action of ABF3 is tightly controlled in Arabidopsis. In the absence of drought stress, ectopic activation of drought response pathways does not occur. In response to drought stress, overexpression of ABF3 results in a reprogramming of the drought response, which is characterized by changes in the timing or strength of expression of some drought response genes, without activating any unexpected gene networks. These results illustrate that important gene networks are highly regulated in Arabidopsis and that engineering stress tolerance may not necessarily cause extensive changes to the transcriptome. © 2010 Abdeen et al; licensee BioMed Central Ltd.

Wang Y.,U.S. Department of Agriculture | Wang Y.,University of California at Davis | You F.M.,Agriculture and Agri Food Canada | Lazo G.R.,U.S. Department of Agriculture | And 5 more authors.
Nucleic Acids Research | Year: 2013

Gene families often show degrees of differences in terms of exon-intron structures depending on their distinct evolutionary histories. Comparative analysis of gene structures is important for understanding their evolutionary and functional relationships within plant species. Here, we present a comparative genomics database named PIECE ( for Plant Intron and Exon Comparison and Evolution studies. The database contains all the annotated genes extracted from 25 sequenced plant genomes. These genes were classified based on Pfam motifs. Phylogenetic trees were pre-constructed for each gene category. PIECE provides a user-friendly interface for different types of searches and a graphical viewer for displaying a gene structure pattern diagram linked to the resulting bootstrapped dendrogram for each gene family. The gene structure evolution of orthologous gene groups was determined using the GLOOME, Exalign and GECA software programs that can be accessed within the database. PIECE also provides a web server version of the software, GSDraw, for drawing schematic diagrams of gene structures. PIECE is a powerful tool for comparing gene sequences and provides valuable insights into the evolution of gene structure in plant genomes. © The Author(s) 2012.

Lafontaine J.D.,Agriculture and Agri Food Canada | Schmidt B.C.,Canadian Food Inspection Agency
ZooKeys | Year: 2010

An annotated check list of the North American species of Noctuoidea (Lepidoptera) is presented, consisting of 3693 species. One-hundred and sixty-six taxonomic changes are proposed, consisting of 13 species-group taxa accorded species status (stat. n. and stat. rev.), 2 revalidated genus-group taxa (stat. rev.), and 2 family-group taxa raised to subfamily. Sixty-nine species-group taxa are downgraded to junior synonyms or subspecies (stat. n., syn. rev., and syn. n.), and 6 genera relegated to synonymy. Sixty-seven new or revised generic combinations are proposed. No new taxa are described. Six non-native species now believed to be established in North America are documented for the first time, namely Simplicia cornicalis (Fabricius, 1794), Nola cucullatella (Linnaeus, 1758), Tyta luctuosa ([Denis & Schiffermüller], 1775), Oligia latruncula ([Denis & Schiffermüller], 1775), Niphonyx segregata (Butler, 1878) and Hecatera dysodea ([Denis & Schiffermüller], 1775). The check list is arranged according to species membership in higher-level taxa (family, subfamily, tribe, subtribe), based on the most recent working hypotheses of a comprehensive phylogenetic framework for the Noctuoidea.

Wang S.,Agriculture and Agri Food Canada | Meckling K.A.,University of Guelph | Tsao R.,Agriculture and Agri Food Canada
Journal of Agricultural and Food Chemistry | Year: 2011

Different foods possess different bioactive compounds with varied antioxidant capacities. When foods are consumed together, the total antioxidant capacity of food mixtures may be modified via synergistic, additive, or antagonistic interactions among these components, which may in turn alter their physiological impacts. The main objective of this study was to investigate these interactions and identify any synergistic combinations. Eleven foods from three categories, including fruits (raspberry, blackberry, and apple), vegetables (broccoli, tomato, mushroom, and purple cauliflower), and legumes (soybean, adzuki bean, red kidney bean, and black bean) were combined in pairs. Four assays (total phenolic content, ferric reducing antioxidant power, 2,2-diphenyl-1-picrylhydrazyl, radical scavenging capacity, and oxygen radical absorbance capacity) were used to evaluate the antioxidant capacities of individual foods and their combinations. The results indicated that within the same food category, 13, 68, and 21% of the combinations produced synergistic, additive, and antagonistic interactions, respectively, while the combinations produced 21, 54, and 25% synergistic, additive, and antagonistic effects, respectively, across food categories. Combining specific foods across categories (e.g., fruit and legume) was more likely to result in synergistic antioxidant capacity than combinations within a food group. Combining raspberry and adzuki bean extracts demonstrated synergistic interactions in all four chemical-based assays. Compositional changes did not seem to have occurred in the mixture. Results in this study suggest the importance of strategically selecting foods or diets to maximum synergisms as well as to minimum antagonisms in antioxidant activity. © 2011 American Chemical Society.

Agency: Cordis | Branch: FP7 | Program: CSA-CA | Phase: KBBE.2010.4-04 | Award Amount: 1.15M | Year: 2011

The main objective of BIO CIRCLE 2 is to foster the knowledge base about FP7 FAFB & the networking capacities of Third Country researchers in order to reinforce their participation in FP7 projects. 3 project goals are distinguished: 1.Disseminate information effectively to Third Country researchers; 2.Organise information days and training for Third Country researchers; 3.Provide Third Country researchers with efficient networking opportunities. 5 European plus 16 Third Country partners (International Cooperation Partner Countries ICPC and Industrialised Countries) will all be involved in the activities. Apart from Kazakhstan and Thailand all involved countries (and the African continent represented by FARA) have signed a bilateral S&T agreement with the EU. The expected impacts are supported by various activities: Enhanced awareness of the Third Country researchers on the FP7 FAFB: WP2 will develop the regional strategies for the Third Country partners. Increased Third Country researchers participation in EU projects: WP3 will organise at least 2 trainings for Third Country researchers at national and regional level, 3 trainings of Third Country BIO NCPs and the organisation of 1 Regional Event per World Region. Strengthened collaborations with Third Countries signatories of bilateral S&T agreements with the EU: WP4 will implement networking activities for Third Country researchers, including brokerage events and working visits of Third Country researchers to EU research institutes and vice versa. Finally WP5 on dissemination activities will increase the awareness of European researchers about the international cooperation in FP7 FAFB. The impact of the activities will be further maximised by: 1.involving other countries that are not partners through a regional approach; 2.linking the BIO CIRCLE 2 activities to the activities of related INCO projects; 3.involving industrialised countries that are global S&T leaders in FAFB related research.

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: ENV.2010.3.1.1-2 | Award Amount: 4.85M | Year: 2011

The Routes project is addressed to discover new routes in wastewater and sludge treatment which allow: a) to prepare sludge for agricultural utilization by transforming it in a very clean and stabilized product regarding the presence of organic micropollutants (conventional and emerging ones) and of heavy metals, and with respect to hygienic aspects and to phytotoxicity; b) to minimize sludge production by innovative solutions which can be based on different approaches, i.e.: i) metabolic uncoupling where the free energy released by electrons transport is dissipated in heat, in the activation of alternative metabolic routes or in the accumulation of polymeric products, ii) the use of microbial fuel cells, iii) the use of sequencing batch biofilter granular reactor (SBBGR), iiii) the integration of a side-stream process in membrane bioreactors; c) to promote recovery of valuable materials from anaerobic digestion, i.e. biopolymers as polyhydroxyalkanoates and fertilizers; e) to set up and prove at practical scale a novel technique for sludge disposal (wet oxidation) as sustainable alternative to nowadays the most used incineration; f) to minimize energy pumping by adjusting solid concentration, on a practical installation where sludge is pumped from the production site to a centralized plant. The general objective of the Routes proposal is therefore to set up a panel of different solutions to be applied in different conditions and circumstances, strictly following the waste hierarchy of the Directive 08/98 on waste. The above solutions will be studied either in laboratory or at practical scale, depending on the maturity of the technology, in order to provide to the Commission and the technical and scientific community applicable solutions and new routes for sludge management, also based on the best integration between the water and sludge treatment lines.

Agency: Cordis | Branch: FP7 | Program: CP-TP | Phase: KBBE.2013.1.2-04 | Award Amount: 8.53M | Year: 2014

The DROPSA consortium will create new knowledge and understanding of the damage and losses of fruit crops resulting from pests and pathogens, with a specific focus on the new and emerging threats due to Drosophila suzukii and quarantine pathogens Pseudomonas syringae, Xanthomonas fragariae and X. arboricola. The project will deliver a cost effective approach that can be widely implemented by the EU fruit industry. The aims and objectives are to: Determine the pathways of introduction and spread of D. suzukii and pathogens into the EU and develop preventative strategies and recommendations against the introduction of other dangerous fruit pests and pathogens. Determine the biology, ecology and interaction of these pests and diseases in different regions of Europe. This will involve a comprehensive evaluation of the life cycles, host ranges, capacities to disperse, the identification of natural enemies, plant-pathogen interactions as well as the semiochemicals involved in the behaviour of D. suzukii. The biology will provide the platform to develop practical solutions for sustainable pest control. Develop innovative and effective control options using approved chemicals, semiochemicals, novel antimicrobial compounds and biological control agents as well as cultural practices, sterile insect techniques and new mode of action compounds. The most reliable and effective control options will be combined to optimise an integrated pest management (IPM) strategy. Develop forecasting and decision support systems and risk mapping as a component of IPM. The economic viability of proposed strategies for fruit crop protection will be evaluated and used to support decision making in the implementation of IPM strategies to protect the EU fruit sector. To protect intellectual property (IP) and to undertake dissemination and exploitation actions to maximise the impact and up take of the recommended IPM by commercial fruit growers.

Xing T.,Carleton University | Laroche A.,Agriculture and Agri Food Canada
Plant Signaling and Behavior | Year: 2011

The regulation mechanisms of any plant-pathogen interaction are complex and dynamic. A proteomic approach is necessary in understanding regulatory networks because it identifies new proteins in relation to their function and ultimately aims to clarify how their expression, accumulation and modification is controlled. One of the major control mechanisms for protein activity in plant-pathogen interactions is protein phosphorylation, and an understanding of the significance of protein phosphorylation in plant-pathogen interaction can be overwhelming. Due to the high number of protein kinases and phosphatases in any single plant genome and specific limitations of any technologies, it is extremely challenging for us to fully delineate the phosphorylation machinery. Current proteomic approaches and technology advances have demonstrated their great potential in identifying new components. Recent studies in well-developed plantpathogen systems have revealed novel phosphorylation pathways, and some of them are off the core phosphorylation cascades. Additional phosphoproteomic studies are needed to increase our comprehension of the different mechanisms and their fine tuning involved in the host resistance response to pathogen attacks. © 2011 Landes Bioscience.

Barnewall E.C.,University of Lethbridge | Barnewall E.C.,Agriculture and Agri Food Canada | de Clerck-Floate R.A.,Agriculture and Agri Food Canada
Arthropod-Plant Interactions | Year: 2012

In an unusual case involving a candidate biological control agent, the histologically complex stem galls of the weevil, Rhinusa pilosa (Coleoptera: Curculionidae) on yellow toadflax (Linaria vulgaris), are rapidly induced during oviposition and reach full size by larval hatch. To investigate gall induction, the oviposition behavior of R. pilosa was described. We experimentally disrupted ovipositing weevils at three key points in the oviposition sequence and compared host-plant tissue responses post disruption, to what occurs during normal gall induction using histological methods. De novo xylem production, intercellular spaces in the cortex, and hyperplasia and hypertrophy of the procambium and pith parenchyma surrounding the egg were some of the tissue- and cellular-level modifications observed only 3-5 days after normal oviposition. Normal gall development was not observed after any of the oviposition disruption treatments, although some of the cellular and tissue responses resembled those found after undisrupted oviposition. Feeding by the female during oviposition canal formation induced wound meristem and callus tissue formation, but no other modifications consistent with gall formation. When females were disrupted about 20 s into oviposition, a homogenously dense substance was observed, which was suspected to be ovipositional fluid. There was minor stem swelling 10 days later and histologically, periclinal cell divisions, de novo xylem, and pith cells with numerous stained plastids were observed as in normal gall development, thus suggesting that ovipositional fluid plays a role in gall induction. © 2012 Her Majesty the Queen in Rights of Canada.

Brua R.B.,Environment Canada | Culp J.M.,Environment Canada | Benoy G.A.,Agriculture and Agri Food Canada
Hydrobiologia | Year: 2011

The assessment of benthic invertebrate community condition is an integral component of freshwater biomonitoring and water quality determination. Several sampling devices have been developed to collect benthic macroinvertebrates, including qualitative, semi-quantitative, and quantitative methods. In this study, we compared several benthic macroinvertebrate metrics and community assemblage measures calculated from data obtained from two sampling methods, namely the Kick- and U-net sampling devices. We reasoned that if the two methods produced similar values for benthic metrics and community composition, then samples collected by these methods should be able to be combined to build larger data sets for use in regional bioassessment analyses. No statistical differences between Kick- and U-net methods were found among standard benthic macroinvertebrate metrics, except for Kicknets collecting more Chironomidae. Invertebrate assemblages were very similar between collection methods, although slightly greater taxonomic richness was found in U-net samples. Bray-Curtis similarity was typically [75% between methods within a stream, while classification strengthsampling- method comparability, an approach for analyzing differences in similarity between groups, indicated invertebrate assemblage similarity between collection methods was virtually identical at approximately 100%. Since these two methods produce similar results, we conclude that benthic macroinvertebrate data collected by these methods can be combined for data analysis and bioassessments with the caveat that mesh size of the sample nets is similar. In addition, if the primary study objective is to assess macroinvertebrate biodiversity, then the U-net sampling device may be more appropriate, despite the slightly greater time needed to complete field sample collection, as it tended to collect a greater diversity of species. © Springer Science+Business Media B.V. 2010.

Ziemienowicz A.,University of Lethbridge | Ziemienowicz A.,Agriculture and Agri Food Canada
Biocatalysis and Agricultural Biotechnology | Year: 2014

Agrobacterium has been widely used as a vector to create transgenic plants. Agrobacterium-mediated gene transfer is governed by various factors of bacterial, host and environmental origin. Applications of this technology include enhancement of plant tolerance to biotic/abiotic stresses, increased crop productivity, pest resistance, phytoremediation, production of biopharmaceuticals, and enhanced nutritional content of crop plants. Agrobacterium has been successfully used to transform various economically and horticulturally important monocot and dicot species by standard tissue culture and in planta transformation techniques. Moreover, a novel Agrobacterium T-DNA-derived nano-complex method has been developed which will be highly valuable for plant biology and biotechnology. •In this review we discuss bacterial, host and environmental factors which affect gene transfer during Agrobacterium-mediated plant transformation.•We demonstrate applications of Agrobacterium-mediated gene transfer for production of plants with desired traits.•Several examples of recent advances in Agrobacterium-mediated plant transgenesis are presented and discussed. © 2013 Elsevier Ltd.

Li Z.,Environment Canada | Li Z.,Agriculture and Agri Food Canada | Huffman T.,Agriculture and Agri Food Canada | McConkey B.,Agriculture and Agri Food Canada | Townley-Smith L.,Agriculture and Agri Food Canada
Remote Sensing of Environment | Year: 2013

Degradation of grassland has become a worldwide environmental concern. This study examined temporal and spatial patterns of grassland potential productivity dynamics between 2000 and 2010 within community pastures (CPs) in Saskatchewan Canada. Data used in the study included Moderate-resolution Imaging Spectroradiometer (MODIS) 250. m time-series NDVI, accumulated precipitation (A-PPT) from September to August and annual stocking intensity (SI). We conducted Mann-Kendall analysis on grassland growing season NDVI (GS-NDVI), A-PPT and SI to demonstrate spatial variation in their temporal trends at local and regional scales. We developed both global Ordinary Linear Square (OLS) and Geographically Weighted Regression (GWR) models to analyze the impacts of climate variation and human activities such as grazing practice on potential pasture productivity from both temporal and spatial contexts. Results show that grasslands in most CPs had increasing trends in GS-NDVI for the time period, and no significantly decreasing trend was found over all CPs at the regional or ecoregional scales. A-PPT itself accounted for over 96% of inter-annual variation in grassland NDVI. At the regional level, the temporal trends in A-PPT and stocking intensity were more significant factors in accounting for spatial variation of NDVI than were A-PPT and SI per se. Results show that the past adopted grazing intensities did not significantly influence grassland potential productivity at either temporal or spatial scales in the study area. © 2013.

Boudjou S.,University of Abderrahmane Mira de Béjaïa | Oomah B.D.,Agriculture and Agri Food Canada | Zaidi F.,University of Abderrahmane Mira de Béjaïa | Hosseinian F.,Carleton University
Food Chemistry | Year: 2013

Two faba bean (Vicia faba L.) subspecies major and minor and lentil seeds grown in Algeria were separated into cotyledons and hulls. These fractions, together with their corresponding whole seeds, were extracted with two solvents, aqueous (70%) acetone and (80%) ethanol, and evaluated for antioxidant activity in relation to their phenolic contents. Acetone selectively extracted tannins from faba beans. The hulls always exhibited high antioxidant activity, measured using the reducing power (RP), antiradical activity (DPPH) or oxygen radical absorbance capacity (ORAC) assays. Aqueous ethanol (80%) extract of lentil hulls exhibited high antioxidant and anti-inflammatory activities preferentially inhibiting 15-LOX (IC50, 55 μg/ml), with moderate COX-1 (IC 50, 66 μg/ml) and COX-2 (IC50, 119 μg/ml) inhibitory effects on the COX pathway, whereas faba bean hull extracts exerted relatively mild LOX inhibitory activity. © 2012 Elsevier Ltd. All rights reserved.

Gan Y.,Agriculture and Agri Food Canada | Liang C.,Environment Canada | Wang X.,Agriculture and Agri Food Canada | McConkey B.,Agriculture and Agri Food Canada
Field Crops Research | Year: 2011

Improving cropping systems may help mitigate greenhouse gas emissions. This study determined the carbon footprint of durum wheat (Triticum turgidum L.) produced in diverse cropping systems. Durum was grown in rotation systems which had different combinations of oilseed, pulse, and cereal crops at five site-years in Saskatchewan, Canada. Total greenhouse gas emissions from the decomposition of crop residues along with various production inputs were used for the estimation of carbon footprint. On average, emissions from the decomposition of crop straw and roots accounted for 25% of the total emissions, those from the production, transportation, storage, and delivery of fertilizers and pesticides to farm gates and their applications 43%, and emissions from farming operations 32%. Durum wheat preceded by an oilseed crop (Brassica napus or Brassica juncea) the previous year had carbon footprint of 0.33kg CO2e kg-1 of grain, or 7% lower than durum in cereal-cereal-durum system. Durum preceded by a biological N-fixing crop (Cicer arietinum chickpea, Lens culinaris lentil, or Pisum sativum pea) the previous year lowered its carbon footprint by 17% compared with durum preceded by a cereal crop. Durum produced in a pulse-pulse-durum system had carbon footprint 0.27kg CO2e kg-1 of grain, 34% lower than durum grown in cereal-cereal-durum systems. Diversifying cropping systems with oilseeds and biological N-fixers significantly lowered carbon footprint of durum wheat. © 2011.

Wong A.,Carleton University | Wong A.,University of Ottawa | Rodrigue N.,University of Ottawa | Rodrigue N.,Agriculture and Agri Food Canada | Kassen R.,University of Ottawa
PLoS Genetics | Year: 2012

Adaptation is likely to be an important determinant of the success of many pathogens, for example when colonizing a new host species, when challenged by antibiotic treatment, or in governing the establishment and progress of long-term chronic infection. Yet, the genomic basis of adaptation is poorly understood in general, and for pathogens in particular. We investigated the genetics of adaptation to cystic fibrosis-like culture conditions in the presence and absence of fluoroquinolone antibiotics using the opportunistic pathogen Pseudomonas aeruginosa. Whole-genome sequencing of experimentally evolved isolates revealed parallel evolution at a handful of known antibiotic resistance genes. While the level of antibiotic resistance was largely determined by these known resistance genes, the costs of resistance were instead attributable to a number of mutations that were specific to individual experimental isolates. Notably, stereotypical quinolone resistance mutations in DNA gyrase often co-occurred with other mutations that, together, conferred high levels of resistance but no consistent cost of resistance. This result may explain why these mutations are so prevalent in clinical quinolone-resistant isolates. In addition, genes involved in cyclic-di-GMP signalling were repeatedly mutated in populations evolved in viscous culture media, suggesting a shared mechanism of adaptation to this CF-like growth environment. Experimental evolutionary approaches to understanding pathogen adaptation should provide an important complement to studies of the evolution of clinical isolates. © 2012 Wong et al.

Whitehead A.,Lancaster University | Beck E.J.,University of Wollongong | Tosh S.,Agriculture and Agri Food Canada | Wolever T.M.S.,University of Toronto
American Journal of Clinical Nutrition | Year: 2014

Background: Health claims regarding the cholesterol-lowering effect of soluble fiber from oat products, approved by food standards agencies worldwide, are based on a diet containing ≥3 g/d of oat b-glucan (OBG). Given the number of recently published randomized controlled trials (RCTs), it is important to update the findings of previous meta-analyses.Objective: The objective was to quantify the effect of >3 g OBG/d on serum cholesterol concentrations in humans and investigate potential effect modifiers.Design: A meta-analysis was performed on 28 RCTs comparing ≥3 g OBG/d with an appropriate control. Systematic searches were undertaken in PubMed, AGRICOLA, and Scopus between 1 January 1966 and 6 June 2013, plus in-house study reports at CreaNutrition AG. Studies were assessed with regard to inclusion/exclusion criteria, and data were extracted from included studies by reviewers working independently in pairs, reconciling differences by consensus. Estimates of the mean reduction in serum cholesterol from baseline between the OBG and control diets were analyzed by using random-effects meta-analysis models and meta-regression.Results: OBG in doses of >3 g/d reduced low-density lipoprotein (LDL) and total cholesterol relative to control by 0.25 mmol/L (95% CI: 0.20, 0.30; P , 0.0001) and 0.30 mmol/L (95% CI: 0.24, 0.35; P , 0.0001), respectively, with some indication of heterogeneity (P = 0.13 and P = 0.067). There was no significant effect of OBG on high-density lipoprotein (HDL) cholesterol or triglycerides and no evidence that dose (range across trials: 3.0-12.4 g/d) or duration of treatment (range: 2-12 wk) influenced the results. LDL cholesterol lowering was significantly greater with higher baseline LDL cholesterol. There was a significantly greater effect for both LDL and total cholesterol in subjects with diabetes compared with those without (although based on few studies).Conclusions: Adding >3 g OBG/d to the diet reduces LDL and total cholesterol by 0.25 mmol/L and 0.30 mmol/L, respectively, without changing HDL cholesterol or triglycerides. © 2014 American Society for Nutrition.

Kovinich N.,Agriculture and Agri Food Canada | Kovinich N.,Carleton University | Saleem A.,University of Ottawa | Arnason J.T.,University of Ottawa | Miki B.,Agriculture and Agri Food Canada
BMC Genomics | Year: 2011

Background: The R locus controls the color of pigmented soybean (Glycine max) seeds. However information about its control over seed coat biochemistry and gene expressions remains limited. The seed coats of nearly-isogenic black (iRT) and brown (irT) soybean (Glycine max) were known to differ by the presence or absence of anthocyanins, respectively, with genes for only a single enzyme (anthocyanidin synthase) found to be differentially expressed between isolines. We recently identified and characterized a UDP-glycose:flavonoid-3-O-glycosyltransferase (UGT78K1) from the seed coat of black (iRT) soybean with the aim to engineer seed coat color by suppression of an anthocyanin-specific gene. However, it remained to be investigated whether UGT78K1 was overexpressed with anthocyanin biosynthesis in the black (iRT) seed coat compared to the nearly-isogenic brown (irT) tissue.In this study, we performed a combined analysis of transcriptome and metabolite data to elucidate the control of the R locus over seed coat biochemistry and to identify pigment biosynthesis genes. Two differentially expressed late-stage anthocyanin biosynthesis isogenes were further characterized, as they may serve as useful targets for the manipulation of soybean grain color while minimizing the potential for unintended effects on the plant system.Results: Metabolite composition differences were found to not be limited to anthocyanins, with specific proanthocyanidins, isoflavones, and phenylpropanoids present exclusively in the black (iRT) or the brown (irT) seed coat. A global analysis of gene expressions identified UGT78K1 and 19 other anthocyanin, (iso)flavonoid, and phenylpropanoid isogenes to be differentially expressed between isolines. A combined analysis of metabolite and gene expression data enabled the assignment of putative functions to biosynthesis and transport isogenes. The recombinant enzymes of two genes were validated to catalyze late-stage steps in anthocyanin biosynthesis in vitro and expression profiles of the corresponding genes were shown to parallel anthocyanin biosynthesis during black (iRT) seed coat development.Conclusion: Metabolite composition and gene expression differences between black (iRT) and brown (irT) seed coats are far more extensive than previously thought. Putative anthocyanin, proanthocyanidin, (iso)flavonoid, and phenylpropanoid isogenes were differentially-expressed between black (iRT) and brown (irT) seed coats, and UGT78K2 and OMT5 were validated to code UDP-glycose:flavonoid-3-O-glycosyltransferase and anthocyanin 3'-O-methyltransferase proteins in vitro, respectively. Duplicate gene copies for several enzymes were overexpressed in the black (iRT) seed coat suggesting more than one isogene may have to be silenced to engineer seed coat color using RNA interference. © 2011 Kovinich et al; licensee BioMed Central Ltd.

Wang Q.,Agriculture and Agri Food Canada | Ellis P.R.,King's College London
British Journal of Nutrition | Year: 2014

The water-soluble, mixed-linkage β-glucan, a form of soluble dietary fibre, is considered the main biologically active component responsible for the capacity of many oat products to lower postprandial glycaemia and fasting plasma cholesterol in human subjects. The present review discusses the physical and chemical properties of oat β-glucan that are considered important predictors of these beneficial metabolic effects. In vitro modelling and animal and human studies have provided compelling evidence showing that the ability of oat β-glucan to increase the viscosity of digesta in the gastrointestinal tract (GIT) is a primary determinant of its blood-glucose and cholesterol-lowering properties. Therefore, the chemical structure, molecular weight (MW), the rate and extent of dissolution and solution rheology of oat β-glucan are key factors in determining the physiological function of oat-containing foods. The structure and properties of oat β-glucan vary between species and varieties of oats, and are also affected by the growing and storage conditions and processing of oat grain. In addition, the extraction and analysis methods may also contribute to the variations in the structure, MW, hydration and solution rheology of β-glucan obtained from different laboratories. Recent work has demonstrated that β-glucan solubility in foods depends on the source of the material and processing conditions; solubility may also be subject to changes during food preparation and storage (such as freezing). In conclusion, both the amount and MW of β-glucan that are solubilised in the GIT need to be considered when assessing the blood-glucose and cholesterol-lowering properties of oat-containing foods. Copyright © 2014 The Authors.

Gariepy T.D.,Agriculture and Agri Food Canada | Lindsay R.,Public Health Agency of Canada Zoonotic Diseases and Special Pathogens | Ogden N.,Public Health Agency of Canada | Gregory T.R.,University of Guelph
Molecular Ecology Resources | Year: 2012

Ticks are among the most important vectors of disease in the Northern Hemisphere, and a better understanding of their feeding behaviour and life cycle is critical to the management and control of tick-borne zoonoses. DNA-based tools for the identification of residual bloodmeals in hematophagous arthropods have proven useful in the investigation of patterns of host use in nature. Using a blind test approach, we challenged the utility of the DNA barcode library for the identification of vertebrate bloodmeals in engorged, field-collected Ixodes scapularis. Universal vertebrate primers for the COI barcode region successfully amplified DNA from the host bloodmeal and only rarely amplified tick DNA. Of the 61 field-collected ticks, conclusive genus- and species-level identification was possible for 72% of the specimens. In all but two cases, barcode-based identification of the bloodmeal was consistent with the morphological identification of the vertebrate host the ticks were collected from. Possible explanations for mismatches or ambiguities are presented. This study validates the utility of the DNA barcode library as a valuable and reliable resource for the identification of unknown bloodmeals in arthropod vectors of disease. Future directions aimed at the refinement of these techniques to gain additional information and to improve the amplification success of digested vertebrate DNA in tick bloodmeals are discussed. © 2012 Blackwell Publishing Ltd.

Gan Y.,Agriculture and Agri Food Canada | Liang C.,Environment Canada | Hamel C.,Agriculture and Agri Food Canada | Cutforth H.,Agriculture and Agri Food Canada | Wang H.,Agriculture and Agri Food Canada
Agronomy for Sustainable Development | Year: 2011

The Earth's climate is rapidly changing largely due to increasing anthropogenic greenhouse gas (GHG) emissions. Agricultural practices during crop production, food processing, and product marketing all generate GHG, contributing to the global climate change. The general public and farmers are urging the development and adoption of effective measures to reduce GHG emissions from all agricultural activities and sectors. However, quantitative information is not available in regard to what strategies and practices should be adopted to reduce emission from agriculture and how crop productivity would affect the intensity of GHG emission. To provide the potential solution, we estimated the carbon footprint [i.e., the total amount of GHG associated with the production and distribution of a given food product expressed in carbon dioxide equivalence (CO2e)] for some of the major field crops grown on the Canadian prairie and assessed the effect of crop sequences on the carbon footprint of durum wheat. Key strategies for reducing the carbon footprint of various field crops grown in semiarid areas were identified. Carbon footprints were estimated using emissions from (1) the decomposition of crop straw and roots; (2) the manufacture of N and P fertilizers and their rates of application; (3) the production of herbicides and fungicides; and (4) miscellaneous farm field operations. Production and application of N fertilizers accounted for 57% to 65% of the total footprint, those from crop residue decomposition 16% to 30%, and the remaining portion of the footprint included CO2e from the production of P fertilizer and pesticides, and from miscellaneous field operations. Crops grown in the Brown soil zone had the lowest carbon footprint, averaging 0.46 kg CO2e kg-1 of grain, whereas crops grown in the Black soil zone had a larger average carbon footprint of 0.83 kg CO2e kg-1 of grain. The average carbon footprint for crops grown in the Dark Brown soil zone was intermediate to the other two at 0.61 kg CO2e kg-1 of grain. One kilogram of grain product emitted 0.80 kg CO2e for canola (Brassica napus L.), 0.59 for mustard (Brassica juncea L.) and flaxseed (Linum usitatissimum L.), 0.46 for spring wheat (Triticum aestivum L.), and 0.20 to 0.33 kg CO 2e for chickpea (Cicer arietinum L.), dry pea (Pisum sativum L.), and lentil (Lens culinaris Medik.). Durum wheat (T. aestivum L.) preceded by an N-fixing crop (i.e., pulses) emitted total greenhouse gases of 673 kg CO 2e, 20% lower than when the crop was preceded by a cereal crop. Similarly, durum wheat preceded by an oilseed emitted 744 kg CO2e, 11% lower than when preceded by a cereal. The carbon footprint for durum grown after a pulse was 0.25 kg CO2e per kg of the grain and 0.28 kg CO2e per kg of the grain when grown after an oilseed: a reduction in the carbon footprint of 24% to 32% than when grown after a cereal. The average carbon footprint can be lowered by as much as 24% for crops grown in the Black, 28% in the Dark Brown, and 37% in the Brown soil zones, through improved agronomic practices, increased N use efficiency, use of diversified cropping systems, adoption of crop cultivars with high harvest index, and the use of soil bioresources such as P-solublizers and arbuscular mycorrhizal fungi in crop production. © INRA and Springer Science+Business Media B.V. 2011.

Kathiria P.,University of Lethbridge | Sidler C.,University of Lethbridge | Golubov A.,University of Lethbridge | Kalischuk M.,University of Lethbridge | And 2 more authors.
Plant Physiology | Year: 2010

Our previous experiments showed that infection of tobacco (Nicotiana tabacum) plants with Tobacco mosaic virus (TMV) leads to an increase in homologous recombination frequency (HRF). The progeny of infected plants also had an increased rate of rearrangements in resistance gene-like loci. Here, we report that tobacco plants infected with TMV exhibited an increase in HRF in two consecutive generations. Analysis of global genome methylation showed the hypermethylated genome in both generations of plants, whereas analysis of methylation via 5-methyl cytosine antibodies demonstrated both hypomethylation and hypermethylation. Analysis of the response of the progeny of infected plants to TMV, Pseudomonas syringae, or Phytophthora nicotianae revealed a significant delay in symptom development. Infection of these plants with TMV or P. syringae showed higher levels of induction of PATHOGENESIS-RELATED GENE1 gene expression and higher levels of callose deposition. Our experiments suggest that viral infection triggers specific changes in progeny that promote higher levels of HRF at the transgene and higher resistance to stress as compared with the progeny of unstressed plants. However, data reported in these studies do not establish evidence of a link between recombination frequency and stress resistance. © 2010 American Society of Plant Biologists.

Gibson J.F.,University of Guelph | Skevington J.H.,Agriculture and Agri Food Canada | Skevington J.H.,Carleton University
Zoological Journal of the Linnean Society | Year: 2013

All global genera of the fly family Conopidae are revised here. A cladistic analysis of 117 morphological characters recorded from 154 species, including representatives of 59 genera and subgenera, recovers a phylogenetic hypothesis for the family. This hypothesis is used as the basis of a new classification for the family. Both Sicini and Zodionini are removed from Myopinae and elevated to subfamilial status. A new tribe, Thecophorini, is proposed within Myopinae to accommodate Thecophora, Scatoccemyia, and Pseudoconops. Two genera, Pseudomyopa and Parazodion, are removed from Dalmanniinae and placed in Myopinae and Zodioninae, respectively. Conopinae is divided into 11 tribes, seven of which are newly described (Asiconopini, Caenoconopini, Gyroconopini, Microconopini, Neoconopini, and Siniconopini). Some examined species are transferred to different or new genera and subgenera. A new genus, Schedophysoconops gen. nov., and subgenus Asiconops (Aegloconops) subgen. nov. within Conopinae are described. A review of character evolution and phylogeography is included in light of the new classification. A catalogue of all genus-group names is included with new emendations noted. © 2013 The Linnean Society of London.

Gibson J.F.,University of Guelph | Skevington J.H.,Agriculture and Agri Food Canada | Skevington J.H.,Carleton University | Kelso S.,Agriculture and Agri Food Canada
Cladistics | Year: 2013

Members of the family Conopidae (Diptera) have been the focus of little targeted phylogenetic research. The most comprehensive test of phylogenetic support for the present subfamily classification of Conopidae is presented here using 66 specimens, including 59 species of Conopidae and seven outgroup taxa. Relationships among subfamily clades are also explored. A total of 6824bp of DNA sequence data from five gene regions (12S ribosomal DNA, cytochrome c oxidase subunit I, cytochrome b, 28S ribosomal DNA and alanyl-tRNA synthetase) are combined with 111 morphological characters in a combined analysis using both parsimony and Bayesian methods. Parsimony analysis recovers three shortest trees. Bayesian analysis recovers a nearly identical tree. Five monophyletic subfamilies of Conopidae are recovered. The rarely acknowledged Zodioninae is restored, including the genera Zodion and Parazodion. The genus Sicus is removed from Myopinae. Morphological synapomorphies are discussed for each subfamily and inter-subfamily clade, including a comprehensive review of the character interpretaions of previous authors. Included are detailed comparative illustrations of male and female genitalia of representatives of all five subfamilies with new morphological interpretation. © The Willi Hennig Society 2012.

Tremblay N.,Agriculture and Agri Food Canada | Wang Z.,Agriculture and Agri Food Canada | Cerovic Z.G.,University Paris - Sud
Agronomy for Sustainable Development | Year: 2012

The optimization of nitrogen (N) fertilization is the object of intense research efforts around the world. Overfertilization is commonly used as a form of insurance against uncertain soil fertility level. However, this practice results in lower nitrogen use efficiency, high levels of residual N after harvest, and losses in the environment. Determining an N recommendation that would preserve actual crop requirements, profitability of the farm, and quality of the environment has been subjected to a number of research initiatives with a variable degree of success. On one hand, soil tests are capable of estimating the intensity of N release at any point in time, but rarely the capacity factor over a longer period. On the other hand, in the context of in-season N applications, crops are often considered good integrators of factors such as the presence of mineral N, climatic conditions, soil properties, and crop management. Strategies have been proposed with plant sensor-based diagnostic information for N recommendations, but the sensitivity of reflectance-based parameters alone do not provide complete satisfaction (delayed sensitivity, need of specific chlorophyll, biomass or cover fraction ranges, lack of specificity to the N stress). Fluorescence sensing methods have been used to monitor crop physiology for years, and they may offer solutions for N status diagnosis over reflectance-based methods. In this paper, we review three plant fluorescence components related to four sensing approaches-variable chlorophyll fluorescence, leaf chlorophyll content-related fluorescence emission ratio, blue-green fluorescence, and epidermal screening of chlorophyll fluorescence by phenolic compounds-from the perspective of their relevance to N fertilization management of agricultural crops. We examine the existence of N-induced changes in each case, together with applications and limitations of the approach. Among these approaches, the fluorescence emission ratio method is the most important and the most widely used to date. However, blue-green fluorescence and epidermal screening of chlorophyll fluorescence by phenolic compounds has also received a great deal of attention particularly with the recent commercial release of instruments which can measure in real time and in vivo both the leaf chlorophyll content and several phenolic compounds (anthocyanins, flavonoïds, hydroxycinnamic acids). Overall, our conclusion is that fluorescence-based technologies allow for highly sensitive plant N status information, independently from soil interference, leaf area, or biomass status. They also allow for probing not only the chlorophyll status but also other physiological parameters known to react to N fertility conditions. These new parameters have the potential to provide new N status indicators that can be assessed remotely in a precision agriculture context. © INRA and Springer Science+Business Media B.V. 2011.

Mlynarek J.J.,Carleton University | Knee W.,Agriculture and Agri Food Canada | Forbes M.R.,Carleton University
Evolutionary Biology | Year: 2014

Closely related host species are known to show variation in the level of resistance towards the same or similar parasite species, but this phenomenon is understudied. Such studies are important for understanding the ecological factors that might promote susceptibility or resistance to parasites: in particular, whether one host species is a larger target of selection for the parasite by virtue of being more abundant locally or more regionally widespread than another host species. In this study, we examined the expression of resistance by two closely related species of damselflies (Nehalennia irene and Nehalennia gracilis) against an Arrenurus water mite species. We show that the host species at each of two isolated sphagnum bogs have statistically indistinguishable levels of prevalence and intensity of infection by mite larvae. Despite having similar measures of parasitism, the regionally less represented species (N. gracilis) showed total resistance, whereas the regionally well-represented species (N. irene) was completely susceptible. Moreover, the form of resistance expressed by N. gracilis was unique, in that the oral glands of the mite were melanised. Also, this mite species was not found outside of isolated bog habitats. These results suggest that there might have been strong historical selection from this mite on the bog specialist, N. gracilis, and that this selection may have resulted in resistance evolving to fixation in a series of isolated populations. © 2013 Springer Science+Business Media New York.

Gariepy T.D.,Agriculture and Agri Food Canada | Haye T.,CABI Inc | Fraser H.,Ontario Ministry of Agriculture and Food | Zhang J.,MoA CABI Joint Laboratory for Biosafety
Journal of Pest Science | Year: 2014

Halyomorpha halys has recently established in countries outside of its Asian area of origin. In the North Eastern USA, this pest causes severe economic loss in agricultural crops. Breeding populations have been confirmed in Switzerland and Canada; however, their pathways of entry and genetic diversity remain unknown. To determine invasion pathways and source population(s), the diversity of specimens from Asia, North America, and Europe was investigated. Genetic diversity in Asia was higher than that in the Canada and Switzerland. Although three haplotypes were detected among Canadian H. halys, one haplotype dominated. In contrast, two out of three haplotypes were found frequently among Swiss samples. Based on molecular data and interception records it appears likely that H. halys in Canada is derived from the movement of established US populations. Further, North American populations likely originated from the Hebei/Beijing regions of China. The area of origin of the Swiss samples remains unclear. Although the dominant haplotype in Switzerland was consistent with Asian samples collected in the Hebei and Beijing provinces, it was not the dominant haplotype in these regions and further sampling is necessary to its confirm the distribution and abundance in the area of origin. The remaining two haplotypes were unique to Switzerland and no matches were found among our Asian samples. Interestingly, no haplotypes were shared between the North American and Swiss samples, indicating that the two invasions were separate and distinct events and did not result from the movement of goods and materials between USA and Europe. © 2013 Her Majesty the Queen in Right of Canada.

Brassard J.,Agriculture and Agri Food Canada | Gagne M.-J.,Agriculture and Agri Food Canada | Genereux M.,Environment Canada | Cote C.,Environment Canada
Applied and Environmental Microbiology | Year: 2012

This study evaluated the presence of pathogenic human and zoonotic viruses on irrigated, field-grown strawberries. Norovirus genogroup I, rotavirus, and swine hepatitis E virus genogroup 3 were detected on strawberries, and irrigation water is suspected as the contamination origin. © 2012, American Society for Microbiology.

Liu D.,Nanjing University of Information Science and Technology | Song J.,Nanjing University of Information Science and Technology | Anderson D.P.,Agriculture and Agri Food Canada | Chang P.R.,Agriculture and Agri Food Canada | Hua Y.,Nanjing University of Information Science and Technology
Cellulose | Year: 2012

Natural plant fibers have unequivocally contributed economic prosperity and sustainability in our daily lives. Particularly, bamboo fibers have been used for industrial applications as diverse as textiles, paper, and construction. Recent renewed interest in bamboo fiber (BF) is primarily targeted for the replacement or reduction in use of glass fiber from non-renewable resources. In this review, various mechanical, chemical, and biological approaches for the preparation and separation of macro-, micro-, and nano-sized fibers from raw bamboo are summarized. The differences in the mechanical, thermal, and other properties of fibers from different materials are linked to their size, aspect ratio, surface charge and groups, and their function in nature. Biocomposites made of BF are considered to be green, environmentally responsible eco-products. Different processing parameters such as fiber extraction, surface modification, and synthesis of the composites affect the characteristics of composites. Fiber length, orientation, concentration, dispersion, aspect ratio, selection of matrix, and chemistry of the matrix must all be considered during fabrication in order to achieve desirable functionalities and performance. Because of the hydrophilic nature of BF, different methods may be adopted to improve interfacial surface adhesion. A better understanding of the fiber structure and characteristics that influence composite performance could lead to the development of additives, coatings, binders, or sizing suitable for natural fiber and a variety of polymeric matrices. © 2012 Springer Science+Business Media B.V.

Hossie T.J.,Carleton University | Hassall C.,University of Leeds | Knee W.,Agriculture and Agri Food Canada | Sherratt T.N.,Carleton University
Journal of Evolutionary Biology | Year: 2013

Evolutionary hypotheses for ageing generally predict that delayed senescence should evolve in organisms that experience lower extrinsic mortality. Thus, one might expect species that are highly toxic or venomous (i.e. chemically protected) will have longer lifespans than related species that are not likewise protected. This remarkable relationship has been suggested to occur in amphibians and snakes. First, we show that chemical protection is highly conserved in several lineages of amphibians and snakes. Therefore, accounting for phylogenetic autocorrelation is critical when conservatively testing evolutionary hypotheses because species may possess similar longevities and defensive attributes simply through shared ancestry. Herein, we compare maximum longevity of chemically protected and nonprotected species, controlling for potential nonindependence of traits among species using recently available phylogenies. Our analyses confirm that longevity is positively correlated with body size in both groups which is consistent with life-history theory. We also show that maximum lifespan was positively associated with chemical protection in amphibian species but not in snakes. Chemical protection is defensive in amphibians, but primarily offensive (involved in prey capture) in snakes. Thus, we find that although chemical defence in amphibians favours long life, there is no evidence that chemical offence in snakes does the same. © 2013 European Society For Evolutionary Biology.

Li X.-Q.,Agriculture and Agri Food Canada | Xing T.,Carleton University | Du D.,University of New Brunswick
Current Issues in Molecular Biology | Year: 2016

Somatic mutation of signal transduction genes or key nodes of the cellular protein network can cause severe diseases in humans but can sometimes genetically improve plants, likely because growth is determinate in animals but indeterminate in plants. This article reviews protein networks; human protein ranking; the mitogenactivated protein kinase (MAPK) and insulin (phosphoinositide 3kinase [PI3K]/phosphatase and tensin homolog [PTEN]/protein kinase B [AKT]) signaling pathways; human diseases caused by somatic mutations to the PI3K/PTEN/ AKT pathway; use of the MAPK pathway in plant molecular breeding; and protein domain evolution. Casitas B-lineage lymphoma (CBL), PTEN, MAPK1 and PIK3CA are among the top-ranked proteins in directional rankings. Eight proteins (ACVR1, CDC42, RAC1, RAF1, RHOA, TGFBR1, TRAF2, and TRAF6) are ranked in the top 50 key players in both signal emission and signal reception and in interaction with many other proteins. Top-ranked proteins likely have major impacts on the network function. Such proteins are targets for drug discovery, because their mutations are implicated in various cancers and overgrowth syndromes. Appropriately managing food intake may help reduce the growth of tumors or malformation of tissues. The role of the protein kinase C/ fatty acid synthase pathway in fat deposition in PTEN/PI3K patients should be investigated. Both the MAPK and insulin signaling pathways exist in plants, and MAPK pathway engineering can improve plant tolerance to biotic and abiotic stresses such as salinity. © 2016, Caister Academic Press. All rights reserved.

Benoy G.A.,Agriculture and Agri Food Canada | Sutherland A.B.,University of New Brunswick | Culp J.M.,University of New Brunswick | Brua R.B.,Environment Canada
Journal of Environmental Quality | Year: 2012

Excessive sedimentation in streams and rivers remains a pervasive problem for the protection of aquatic habitat and the sustainability of aquatic communities. Whereas water quality criteria have been determined for suspended sediments in many jurisdictions across North America, comparably little has been done for deposited (also known as bedded) sediments. Through Canada's National Agri-Environmental Standards Initiative, assessment techniques and analytical tools were developed for estimating environmental thresholds for deposited sediments in agricultural watersheds in New Brunswick (NB) and Prince Edward Island (PEI) in the Atlantic Maritimes of Canada. Physical thresholds were developed through assessment of geomorphic metrics, which were then analyzed using y-intercept and 25th percentile approaches. For NB, there was strong agreement in physical thresholds for both analytical approaches (e.g., percent fines <2 mm were 7.5 for y-intercept and 6.9 for 25th percentile approaches). In contrast, physical thresholds for PEI differed considerably between approaches (e.g., percent fines <2 mm were 6.1 for y-intercept and 19.6 for 25th percentile approaches), likely due to a narrower range in agricultural land cover. Cross-calibration of our provisional physical thresholds for NB with ecological (i.e., benthic macroinvertebrate) assessments show that ecological thresholds, calculated as change-points in relationships between Ephemeroptera-Plecoptera-Trichoptera relative abundance or Modified Family Biotic Index and geomorphic criteria, were more liberal than physical thresholds. These results suggest that provisional thresholds developed using geomorphic criteria should demarcate change from the least disturbed condition and reduce the risk of sedimentation degrading benthic ecosystems. © 2012 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Sun L.,Carleton University | Mitchell S.W.,Carleton University | Davidson A.,Carleton University | Davidson A.,Agriculture and Agri Food Canada
International Journal of Climatology | Year: 2012

A multi-index drought (MID) model was developed to combine the strengths of various drought indices for agricultural drought risk assessment on the Canadian prairies, as related to spring wheat crop yield. The model automatically selects and combines optimum drought indices derived from the preceding and current months as they become available to better match the conditions (both spatially and temporally) where they work well. The cross-validation results showed that (1) the prediction accuracy of the MID model is better than (or occasionally equal to) using any single drought index for all modelling stages, (2) drought indices derived from the recharge period are useful for early drought risk detection, (3) model prediction accuracy improved as the growing season progressed with the most accurate assessments at the beginning of August, and (4) the model performed best in the more arid locations in the southern prairies, which tend to have a more variable precipitation regime. The model assessment results provide the spatial intensity distribution of possible drought progression and recession before and during the growing season, and can be used with complementary information in agricultural drought risk management and mitigation strategies. © 2011 Royal Meteorological Society.

Qian B.,Agriculture and Agri Food Canada | Gameda S.,Agriculture and Agri Food Canada | Zhang X.,Environment Canada | De Jong R.,Agriculture and Agri Food Canada
Climatic Change | Year: 2012

It is theoretically interesting for climate change detection and practically important for agricultural producers to know whether climate change has influenced agroclimatic conditions and, if so, what the potential impacts are. We present analyses on statistical differences in means and variances of agroclimatic indices between three 30-year periods in the 20th century (i. e., 1911-1940, 1941-1970 and 1971-2000). We found many occurrences of statistically significant changes in means between pairs of the three 30-year periods. The findings consistently support agroclimatic trends identified from trend analysis as an earlier growing season start and an earlier end to spring frost (SF), together with an extended growing season, more frost-free days (FFD) and more available heat units were often found in the later 30-year periods as compared to the earlier ones. In addition, this study provides more detailed quantitative information than the trend signals for the practical interests of agricultural applications. Significant changes were detected for SF and FFD at a much larger percentage of stations between the latter two 30-year periods (1941-1970 vs. 1971-2000) as compared to the earlier two periods (1911-1940 vs. 1941-1970). In contrast, changes in variances of the selected agroclimatic indices were less evident than changes in their means, based on the percentage of stations showing significant differences. We also present new climate averages of the selected agroclimatic indices that can be useful for agricultural planning and management. © 2011 U.K. Crown.

Regand A.,Agriculture and Agri Food Canada | Chowdhury Z.,University of Toronto | Tosh S.M.,Agriculture and Agri Food Canada | Wolever T.M.S.,University of Toronto | And 2 more authors.
Food Chemistry | Year: 2011

The interaction between oat β-glucan and other food components has the potential to influence starch digestibility and consequently affect its bioactivity in reducing glycemic responses. Blood glucose concentrations were measured before and after ingesting wheat and oat granolas, with 0.6 and 6.2 g of β-glucan, respectively, and two starch doses (40 and 60 g). As the in vitro extract viscosity of β-glucan increased, the in vitro starch digestibility was reduced and the glucose responses were lowered. The peak blood glucose response (PBGR) and the incremental area under the curve (iAUC) were lower in the 40 g than in the 60 g starch formulation. β-Glucan was significantly more active in reducing PBGR and iAUC when the β-glucan/starch ratio was 1.6:10 rather than 1.1:10. This information is valuable for new product development and for quality assessment of bioactive foods containing oat β-glucan. © 2011 Elsevier Ltd. All rights reserved.

Chambers P.A.,Environment Canada | McGoldrick D.J.,Environment Canada | Brua R.B.,Environment Canada | Vis C.,Environment Canada | And 2 more authors.
Journal of Environmental Quality | Year: 2012

Inputs of nutrients (P and N) to freshwaters can cause excessive aquatic plant growth, depletion of oxygen, and deleterious changes in diversity of aquatic fauna. As part of a "National Agri-Environmental Standards Initiative," the Government of Canada committed to developing environmental thresholds for nutrients to protect ecological condition of agricultural streams. Analysis of data from >200 long-term monitoring stations across Canada and detailed ecological study at ̃70 sites showed that agricultural land cover was associated with increased nutrient concentrations in streams and this, in turn, was associated with increased sestonic and benthic algal abundance, loss of sensitive benthic macroinvertebrate taxa, and an increase in benthic diatom taxa indicative of eutrophication. Chemical thresholds for N and P were defined by applying five approaches, employing either a predetermined percentile to a water chemistry data set or a relationship between water chemistry and land cover, to identify boundaries between minimally disturbed and impaired conditions. Comparison of these chemical thresholds with biological thresholds (derived from stressor-response relationships) produced an approach for rationalizing these two types of thresholds and deriving nutrient criteria. The resulting criteria were 0.01 to 0.03 mg L -1 total P and 0.87 -1.2 mg L -1 total N for the Atlantic Maritime, 0.02 mg L -1 total P and 0.21 mg L -1 total N for the Montane Cordillera, ̃0.03 mg L -1 total P and ̃1.1 mg L -1 total N for the Mixedwood Plains, and ̃0.10 mg L -1 total P and 0.39-0.98 mg L -1 total N for the interior prairies of Canada. Adoption of these criteria should result in greater likelihood of good ecological condition with respect to benthic algal abundance, diatom composition, and macroinvertebrate composition. © 2012 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Fu Y.-B.,Agriculture and Agri Food Canada | Allaby R.G.,University of Warwick
Genetic Resources and Crop Evolution | Year: 2010

Crop wild relatives are invaluable sources of novel genes for crop improvement and adaptation to changing environments. We assessed phylogenetic relationships among 29 Linum accessions representing 16 species, including cultivated flax and its progenitor pale flax, based on four non-coding regions of chloroplast DNA sequences. We obtained a cpDNA network showing that these 16 Linum species are appropriately connected based on previously defined taxonomic sections; these connections reflect the same evolutionary pathways as determined from earlier morphological and cytological data. These relationships also support an earlier hypothesis that cultivated flax is probably descended from a single domestication of pale flax plants, apparently for oil usage. The detailed species network not only is significant for understanding evolutionary relationships of Linum species, but also useful for classifying exotic gene pools of cultivated flax as a part of the ongoing exploration of new genetic diversity for flax improvement. © 2009 Springer Science+Business Media B.V.

Lysyk T.J.,Agriculture and Agri Food Canada | Selinger L.B.,University of Lethbridge
Journal of Economic Entomology | Year: 2012

We examined the effects of temperature on mortality of larval stable ßy [Stomoxys calcitrans (L.)] caused by Bacillus thuringiensis tolworthi 4L3, B. t. darmastedensis 4M1, B. t. thompsoni 401, B. t. thuringiensis HD2, and B. t. kurstaki HD945. At moderate doses, mortality caused by all isolates ranged from 87 to 99% at 15°C and declined to 29-63% as temperature increased to 30°C. A similar pattern was seen when a higher dose was used, except that the reduction in mortality at warmer temperatures was not as great as was seen with the moderate doses. Insecticidal activity of each isolate against rst-instar larvae was reduced by only 5-15% after 5 d in the medium. Mortality of second-and third-instar larvae ranged from 2 to 21%, suggesting the isolates were less effective against larger larvae. © 2012 Entomological Society of America.

Naghmouchi K.,Agriculture and Agri Food Canada | Naghmouchi K.,Faculte des science Laboratoire des Microorganismes et Biomolecules Actives | Baah J.,Faculte des science Laboratoire des Microorganismes et Biomolecules Actives | Hober D.,Laboratoire Of Virologie Ea3610 | And 4 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013

Pathogens resistant to most conventional antibiotics are a harbinger of the need to discover novel antimicrobials and anti-infective agents and develop innovative strategies to combat them. The aim of this study was to assess the in vitro activity of colistin alone or in combination with two bacteriocins, nisin A and pediocin PA-1/AcH, against Salmonella choleraesuis ATCC 14028, Pseudomonas aeruginosa ATCC 27853, Yersinia enterocolitica ATCC 9610, and Escherichia coli ATCC 35150 (O157:H7). The strain most sensitive to colistin was enterohemorrhagic E. coli O157:H7, which was inhibited at a concentration of about 0.12 μg/ml. When nisin A (1.70 μg/ml) or pediocin PA-1/AcH (1.56 μg/ml) was combined with colistin, the concentrations required to inhibit E. coli O157:H7 were 0.01 and 0.03 μg/ml, respectively. The in vitro antigenotoxic effect of colistin was determined by using the comet assay method to measure the level of DNA damage in freshly isolated human peripheral blood leukocytes (PBLs) incubated with colistin for 1 h at 37°C. Changes in the tail extents of PBLs of about 69.29±0.08 μmwere observed at a final colistin concentration of about 550 ng/ml. Besides the synergistic effect, the combination of colistin (1 mg/ml) and nisin (2 mg/ ml) permitted us to re-evaluate the toxic effect of colistin on Vero (monkey kidney epithelial) cells. Copyright © 2013, American Society for Microbiology. All Rights Reserved.

Pattey E.,Agriculture and Agri Food Canada | Qiu G.,Environment Canada
Journal of the Air and Waste Management Association | Year: 2012

Particulate matter (PM) has long been recognized as an air pollutant due to its adverse health and environmental impacts. As emission of PM from agricultural operations is an emerging air quality issue, the Agricultural Particulate Matter Emissions Indicator (APMEI) has been developed to estimate the primary PM contribution to the atmosphere from agricultural operations on Census years and to assess the impact of practices adopted to mitigate these emissions at the soil landscape polygon scale as part of the agri-environmental indicator report series produced by Agriculture and Agri-Food Canada. In the APMEI, PM emissions from animal feeding operations, wind erosion, land preparation, crop harvest, fertilizer and chemical application, grain handling, and pollen were calculated and compared for the Census years of 1981-2006. In this study, we present the results for PM10and PM2.5, which exclude chemical application and pollen sources as they only contribute to total suspended particles. In 2006, PM emissions from agricultural operations were estimated to be 652.6 kt for PM10and 158.1 kt for PM2.5. PM emissions from wind erosion and land preparation account for most of PM emissions from agricultural operations in Canada, contributing 82% of PM10and 76% of PM2.5in 2006. Results from the APMEI show a strong reduction in PM emissions from agricultural operations between 1981 and 2006, with a decrease of 40% (442.8 kt) for PM10and 47% (137.7 kt) for PM2.5. This emission reduction is mainly attributed to the adoption of conservation tillage and no-till practices and the reduction in the area of summerfallow land. Implications: Increasing sustainability in agriculture often means adapting management practices to have a beneficial impact on the environment while maintaining or increasing production and economic benefits. We developed an inventory of primary PM emissions from agriculture in Canada to better quantify the apportionment, spatial distribution, and trends for Census years 1981-2006. We found major reductions of 40% in PM10and 47% in PM2.5emissions over the 25-yr period as a co-benefit of increasing carbon sequestration in agricultural soils. Indeed, farmers adopted conservation tillage/no-till practices, increased usage of cover crops, and reduced summerfallow, in order to increase soil organic matter and reduce carbon dioxide emissions, which also reduced primary PM emissions, although the agricultural production increased over the period. Supplemental Materials: Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for primary PM emissions at the soil landscape polygon scale from Canadian agricultural sources in 2006 (adapted from Pattey et al., 2010) and for previous Census years between 1981 and 2001. © 2012 A&WMA.

Gariepy T.D.,Agriculture and Agri Food Canada | Haye T.,CABI Inc | Zhang J.,MoA CABI Joint Laboratory for Biosafety
Molecular Ecology | Year: 2014

Evaluation of host-parasitoid associations can be tenuous using conventional methods. Molecular techniques are well placed to identify trophic links and resolve host-parasitoid associations. Establishment of the highly invasive brown marmorated stink bug, Halyomorpha halys (Hemiptera: Pentatomidae), outside Asia has prompted interest in the use of egg parasitoids (Hymenoptera: Scelionidae) as biological control agents. However, little is known regarding their host ranges. To address this, a DNA barcoding approach was taken wherein general PCR primers for Scelionidae and Pentatomidae were developed to amplify and sequence >500-bp products within the DNA barcoding region of the cytochrome oxidase I (COI) gene that would permit the identification of key players in this association. Amplification of DNA from Pentatomidae and Scelionidae was consistent across a broad range of taxa within these families, and permitted the detection of Scelionidae eggs within H. halys 1 h following oviposition. In laboratory assays, amplification and sequencing of DNA from empty, parasitized eggs was successful for both host (100% success) and parasitoid (50% success). When applied to field-collected, empty egg masses, the primers permitted host identification in 50-100% of the eggs analysed, and yielded species-level identifications. Parasitoid identification success ranged from 33 to 67% among field-collected eggs, with genus-level identification for most specimens. The inability to obtain species-level identities for these individuals is due to the lack of coverage of this taxonomic group in public DNA sequence databases; this situation is likely to improve as more species are sequenced and recorded in these databases. These primers were able to detect and identify both pentatomid host and scelionid parasitoid in a hyperparasitized egg mass, thereby clarifying trophic links otherwise unresolved by conventional methodology. © 2013 John Wiley & Sons Ltd.

Sabourin L.,Agriculture and Agri Food Canada | Duenk P.,University of Western Ontario | Bonte-Gelok S.,Environment Canada | Payne M.,Ontario Ministry of Food | And 2 more authors.
Science of the Total Environment | Year: 2012

Several recent greenhouse studies have established the potential for uptake of human pharmaceuticals from soil fertilized with municipal biosolids into a variety of crops. In the present study, a field experiment was undertaken to evaluate the uptake of organic micropollutants from soil fertilized with municipal biosolids at a regulated application rate into tomatoes, carrots, potatoes and sweet corn produced under normal farming conditions. The vegetables were grown according to farming practices mandated by the province of Ontario Canada, the key feature being a one-year offset between biosolid application and the harvest of crops for human consumption. Biosolids at application, and crop samples following harvest were analyzed for 118 pharmaceuticals and transformation products, 17 hormones or hormone transformation products, and 6 parabens. Analyte concentrations in the biosolids were consistent with those detected in other surveys. Eight of the 141 analytes were detected in one or two crop replicates at concentrations ranging from 0.33 to 6.25. ng/g dry weight, but no analytes were consistently detected above the detection limit in all triplicate treated plots. Overall, this study suggests that the potential for micropollutant uptake into crops under normal farming conditions is low. © 2012.

Baum B.R.,Agriculture and Agri Food Canada | Edwards T.,Agriculture and Agri Food Canada | Johnson D.A.,Carleton University
Molecular Genetics and Genomics | Year: 2014

The genus Dasypyrum contains two species: the annual and widespread D. villosum (2x = 2n = 14) and the perennial and generally rare D. breviaristatum (2x = 2n = 14 and 4x = 2n = 28). The origin of the latter and its genome constitution have been subject of several studies. There is agreement that the genome of the diploid D. villosum (VV) is different from the diploid cytotype of D. breviaristatum (VbVb), but there is no agreement of the constitution of the tetraploid cytotype, specifically whether is it an autotetraploid or an allotetraploid. This is a long-standing disagreement that this study aims to resolve using the 5S nrDNA as a genomic marker. Our studies suggest that the 4x D. breviaristatum is an allotetraploid (VVVbVb). © 2014 Her Majesty the Queen in Right of Canada.

Rintoul T.L.,Agriculture and Agri Food Canada | Eggertson Q.A.,Carleton University | Levesque C.A.,Agriculture and Agri Food Canada
Methods in Molecular Biology | Year: 2012

Supporting the identification of unknown strains or specimens by sequencing a genetic marker commonly used for phylogenetics or DNA barcoding is now standard practice for mycologists and plant pathologists. Does one have a new species when a strain differs by a few base pairs when compared to reference sequences from taxonomically well-characterized species that do not differ morphologically from this new strain? If variation at the intra- and interspecific levels for the locus used for identification is already understood for all the closely related species, it is possible to make a reliable prediction of a new species status, but ultimately this question can only be properly addressed by determining the presence or absence of gene flow among a group of strains of the putative new species and strains of previously delimited species. The Phylogenetic Species Concept (PSC) and its assessment using multigene phylogeny and Genealogical Concordance Phylogenetic Species Recognition (GCPSR) are the basis for this chapter. The theoretical framework and a variety of tools to apply these concepts are explained, to assist in the assessment of whether a species is distinct or new when confronted with some sequence divergence from reference data. © 2012 Springer Science+Business Media, LLC.

Bilichak A.,Agriculture and Agri Food Canada | Kovalchuk I.,University of Lethbridge
Journal of Experimental Botany | Year: 2016

A growing number of reports indicate that plants possess the ability to maintain a memory of stress exposure throughout their ontogenesis and even transmit it faithfully to the following generation. Some of the features of transgenerational memory include elevated genome instability, a higher tolerance to stress experienced by parents, and a cross- Tolerance. Although the underlying molecular mechanisms of this phenomenon are not clear, a likely contributing factor is the absence of full-scale reprogramming of the epigenetic landscape during gametogenesis; therefore, epigenetic marks can occasionally escape the reprogramming process and can be passed on to the progeny. To date, it is not entirely clear which part of the epigenetic landscape is more likely to escape the reprogramming events, and whether such a process is random or directed and sequence specific. The identification of specific epigenetic marks associated with specific stressors would allow generation of stress- Tolerant plants through the recently discovered techniques for precision epigenome engineering. The engineered DNA-binding domains (e.g. ZF, TALE, and dCas9) fused to particular chromatin modifiers would make it possible to target epigenetic modifications to the selected loci, probably allowing stress tolerance to be achieved in the progeny. This approach, termed epigenetic breeding, along with other methods has great potential to be used for both the assessment of the propagation of epigenetic marks across generations and trait improvement in plants. In this communication, we provide a short overview of recent reports demonstrating a transgenerational response to stress in plants, and discuss the underlying potential molecular mechanisms of this phenomenon and its use for plant biotechnology applications. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Scott J.L.,Carleton University | Kawahara A.Y.,University of Maryland University College | Skevington J.H.,Agriculture and Agri Food Canada | Yen S.-H.,National Sun Yat - sen University | And 3 more authors.
Nature Communications | Year: 2010

Animal communication signals can be highly elaborate, and researchers have long sought explanations for their evolutionary origins. For example, how did signals such as the tail-fan display of a peacock, a firefly flash or a wolf howl evolve? Animal communication theory holds that many signals evolved from non-signalling behaviours through the process of ritualization. Empirical evidence for ritualization is limited, as it is necessary to examine living relatives with varying degrees of signal evolution within a phylogenetic framework. We examine the origins of vibratory territorial signals in caterpillars using comparative and molecular phylogenetic methods. We show that a highly ritualized vibratory signal - anal scraping - originated from a locomotory behaviour - walking. Furthermore, comparative behavioural analysis supports the hypothesis that ritualized vibratory signals derive from physical fighting behaviours. Thus, contestants signal their opponents to avoid the cost of fighting. Our study provides experimental evidence for the origins of a complex communication signal, through the process of ritualization.

Aldai N.,University of the Basque Country | Lavin P.,Institute Ganaderia Of Montana | Kramer J.K.G.,Agriculture and Agri Food Canada | Jaroso R.,Institute Ganaderia Of Montana | Mantecon A.R.,Institute Ganaderia Of Montana
Meat Science | Year: 2012

This study was designed to compare the quality of veal produced from 'Tudanca × Charolais' cross (n = 6) and Limousin (n = 6) breeds when allowed to feed freely on mountain pastures and suckle naturally from birth to 7. months of age. After 80. days of age calves also had access to concentrate (maximum of 3. kg/day), while mothers did not. At slaughter, Limousin calves were heavier (P< 0.01) and provided better carcass yield (P< 0.05) and conformation (P< 0.001) than Tudanca calves. Tudanca beef provided higher fat content (P< 0.05) was less tough (P< 0.05), and was scored as more tender and juicy (P< 0.1) with higher acceptability than Limousin beef (P< 0.1). In general, Tudanca had a better fatty acid profile than Limousin beef, especially in terms of the content of polyunsaturated (P< 0.05), long-chain polyunsaturated fatty acids (P< 0.05) and their n-6/n-3 ratios (P< 0.1), as well as vaccenic acid (P< 0.1) and the overall trans-18:1 isomer profile. © 2012 Elsevier Ltd.

Monreal C.M.,Agriculture and Agri Food Canada | Sultan Y.,Carleton University | Schnitzer M.,Agriculture and Agri Food Canada
Geoderma | Year: 2010

We report on the spatial arrangement, chemical composition and stabilization of soil organic matter (SOM) in nano-size structures isolated from a clay fraction of a cultivated Black Chernozem of Canada. Both soil fractions were characterized by Transmission Electron Microscopy (TEM), Pyrolysis Field Ionization Mass Spectrometry (Py-FIMS) and radiocarbon dating, which assisted to better understand the role of SOM and inorganic colloids in the stabilization of carbon and nitrogen at the nm scale. Observations made by TEM indicated that SOM in nano-size fractions occurred mainly in organo-mineral complexes but also in solitary structures of humic substances that formed a carbonaceous network of single strands linking clusters of humic materials and minerals, ranging from a few nm to μm in size. Observations by TEM indicate that humic substances facilitated the spatial arrangement of minerals, thus contributing to physical and physico-chemical stabilization of SOM in nano-size structures. The thermal products evolved during Py-FIMS analyses showed that SOM had greater thermal stability in nano-size structures than in the clay fraction, indicating differences in physical adsorption, cross-linking, polymerization, and/or polycondensation reactions. The SOM in nano-size structures accumulated carbohydrates, N-heterocyclics, peptides, alkylaromatics but was depleted in fatty acids, whereas SOM in the clay fraction was enriched in phenols, lignin monomers, lipids and fatty acids. © 2010.

Tsopmo A.,Carleton University | Muir A.D.,Agriculture and Agri Food Canada
Journal of Agricultural and Food Chemistry | Year: 2010

A high-performance liquid chromatography method was developed to obtain fingerprints of secondary metabolites of 12 lentil cultivars grown under the same environmental condition. Extracts (100% methanol and methanol-water (1:1)) were analyzed by RP-HPLC. Full photodiode array (191-360 nm) data were collected and used for cluster analysis. Methanol and methanol-water extracts showed slightly different clustering patterns. In the dendogram of methanol extracts, CDC Richlea appeared as an isolated group, whereas Indianhead was the isolated group in methanol-water extracts. The cultivar CDC Milestone was selected for further evaluation because of the presence of three peaks (8.9, 16.7, and 32.7 min) that were absent in other cultivars or present in very small amounts. Chromatographic separations of the methanol extract afforded several compounds including the novel 4-chloro-1H-indole-3-N-methylacetamide (13) as well as itaconic acid (3), arbutin (5), gentisic acid 5-O-[β-d-apiofuranosyl- (1→2)-β-d-xylopyranoside] (9), and (6S,7Z,9R)-9-hydroxymegastigma-4,7- dien-3-one-9-O-β-d-apiofuranosyl-(1→2)-β-d-glucopyranoside (14), which are described for the first time from lentils. Structures were determined by high-resolution NMR experiments. © 2010 American Chemical Society.

Agil R.,Carleton University | Oomah D.B.,Agriculture and Agri Food Canada | Mazza G.,Agriculture and Agri Food Canada | Hosseinian F.S.,Carleton University
Food and Bioprocess Technology | Year: 2012

Optimization conditions for alkylresorcinols (ARs) extraction from triticale bran were determined using response surface methodology. A central composite design was used to determine the effects of extraction temperature (degrees Celsius) and solid-to-solvent ratio (weight per volume) on yield of saturated, unsaturated and total ARs. Extraction of ARs was affected significantly (p value ≤ 0.05) by temperature and solid-to-solvent ratio on the yield of saturated, unsaturated and total ARs. The highest quantity of total ARs from triticale bran was extracted at 24 °C between 16 and 24 h at a solid-to-solvent ratio (weight per volume) of 1:40 and ranged from 278 to 308 mg/100 g, while saturated and unsaturated ARs were 163 to 225 mg/100 g and 22 to 29 mg/100 g, respectively. The ARs identified by high-performance liquid chromatography included: C15:0, C17:0, C19:0, C21:0, C23:0 and C25:0. Also some unsaturated analogues (12. 4% to 14. 0%) were found including C17:1, C19:1, C21:1 and C23:1. Analysis of variance (p value = 0. 05) indicated that the response surface methodology (RSM) developed for saturated, unsaturated and total ARs were adequate and explained most of the variability (85% to 89%) with high coefficient of multiple determination (R 2 = 0.89). The main effect of the response variable was quadratic rather than a linear function. Our results showed that RSM is a tool that is useful to optimise experimental conditions for the extraction of ARs. © 2011 Springer Science+Business Media, LLC.

Dettman J.R.,University of Ottawa | Rodrigue N.,Agriculture and Agri Food Canada | Melnyk A.H.,University of Ottawa | Wong A.,Carleton University | And 2 more authors.
Molecular Ecology | Year: 2012

Experimental evolution (EE) combined with whole-genome sequencing (WGS) has become a compelling approach to study the fundamental mechanisms and processes that drive evolution. Most EE-WGS studies published to date have used microbes, owing to their ease of propagation and manipulation in the laboratory and relatively small genome sizes. These experiments are particularly suited to answer long-standing questions such as: How many mutations underlie adaptive evolution, and how are they distributed across the genome and through time? Are there general rules or principles governing which genes contribute to adaptation, and are certain kinds of genes more likely to be targets than others? How common is epistasis among adaptive mutations, and what does this reveal about the variety of genetic routes to adaptation? How common is parallel evolution, where the same mutations evolve repeatedly and independently in response to similar selective pressures? Here, we summarize the significant findings of this body of work, identify important emerging trends and propose promising directions for future research. We also outline an example of a computational pipeline for use in EE-WGS studies, based on freely available bioinformatics tools. © 2012 Blackwell Publishing Ltd.

Ziemienowicz A.,University of Lethbridge | Shim Y.-S.,Agriculture and Agri Food Canada | Shim Y.-S.,Nunhems United States Inc. | Matsuoka A.,University of Lethbridge | And 2 more authors.
Plant Physiology | Year: 2012

Genetic transformation of monocotyledonous plants still presents a challenge for plant biologists and biotechnologists because monocots are difficult to transform with Agrobacterium tumefaciens, whereas other transgenesis methods, such as gold particlemediated transformation, result in poor transgene expression because of integration of truncated DNA molecules. We developed a method of transgene delivery into monocots. This method relies on the use of an in vitro-prepared nano-complex consisting of transferred DNA, virulence protein D2, and recombination protein A delivered to triticale microspores with the help of a Tat 2 cell-penetrating peptide. We showed that this approach allowed for single transgene copy integration events and prevented degradation of delivered DNA, thus leading to the integration of intact copies of the transgene into the genome of triticale plants. This resulted in transgene expression in all transgenic plants regenerated from microspores transfected with the full transferred DNA/protein complex. This approach can easily substitute the bombardment technique currently used for monocots and will be highly valuable for plant biology and biotechnology. © 2012 American Society of Plant Biologists. All Rights Reserved.

Gan Y.,Gansu Agricultural University | Gan Y.,Agriculture and Agri Food Canada | Liang C.,Environment Canada | Chai Q.,Gansu Agricultural University | And 3 more authors.
Nature Communications | Year: 2014

Wheat is one of the world's most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing carbon emissions. Here we quantify the carbon footprint of alternative wheat production systems suited to semiarid environments. We find that integrating improved farming practices (that is, fertilizing crops based on soil tests, reducing summerfallow frequencies and rotating cereals with grain legumes) lowers wheat carbon footprint effectively, averaging -256 kg CO2 eq ha-1 per year. For each kg of wheat grain produced, a net 0.027-0.377 kg CO2 eq is sequestered into the soil. With the suite of improved farming practices, wheat takes up more CO2 from the atmosphere than is actually emitted during its production. © 2014 Macmillan Publishers Limited. All rights reserved.

Main A.R.,University of Saskatchewan | Headley J.V.,Environment Canada | Peru K.M.,Environment Canada | Michel N.L.,University of Saskatchewan | And 3 more authors.
PLoS ONE | Year: 2014

Neonicotinoids currently dominate the insecticide market as seed treatments on Canada's major Prairie crops (e.g., canola). The potential impact to ecologically significant wetlands in this dominantly agro-environment has largely been overlooked while the distribution of use, incidence and level of contamination remains unreported. We modelled the spatial distribution of neonicotinoid use across the three Prairie Provinces in combination with temporal assessments of water and sediment concentrations in wetlands to measure four active ingredients (clothianidin, thiamethoxam, imidacloprid and acetamiprid). From 2009 to 2012, neonicotinoid use was increasing; by 2012, applications covered an estimated ∼11 million hectares (44% of Prairie cropland) with >216,000 kg of active ingredients. Thiamethoxam, followed by clothianidin, were the dominant seed treatments by mass and area. Areas of high neonicotinoid use were identified as high density canola or soybean production. Water sampled four times from 136 wetlands (spring, summer, fall 2012 and spring 2013) across four rural municipalities in Saskatchewan similarly revealed clothianidin and thiamethoxam in the majority of samples. In spring 2012 prior to seeding, 36% of wetlands contained at least one neonicotinoid. Detections increased to 62% in summer 2012, declined to 16% in fall, and increased to 91% the following spring 2013 after ice-off. Peak concentrations were recorded during summer 2012 for both thiamethoxam (range:

Aldai N.,University of the Basque Country | de Renobales M.,University of the Basque Country | Barron L.J.R.,University of the Basque Country | Kramer J.K.G.,Agriculture and Agri Food Canada
European Journal of Lipid Science and Technology | Year: 2013

Adverse health effect of trans fatty acids (TFAs) are well recognized, which has precipitated efforts to reduce their content in food products. With the decline of dietary TFAs derived from partial oil hydrogenation, interest is focused on the remaining sources of dietary TFAs derived from ruminants (rTFA), deodorized vegetable oils, trans isomerization during frying, and synthetic conjugated FA (CFA) supplements. Partial hydrogenation and heat-treated oils result in a random distribution of TFA isomers, whereas rTFAs contain specific isomers resulting from enzymatic processes. Reviews of human observational and metabolic intervention studies have suggested that consumption of rTFAs at current levels should not raise health concerns. However, these studies were not based on rTFA levels currently sold in retail markets. Current feeding practices of ruminants result in higher total TFAs with trans-18:1 isomers other than vaccenic acid, and many CFAs other than rumenic acid. The definition of TFA adopted by several countries does not distinguish among isolated TFAs of concern and ignores CFAs that should be included in total TFA due to their negative health effects. Accurate TFA definition establishment and nutritional assessment of individual TFA isomers is needed for labeling purposes. Also required are adoptions of analytical methods to resolve all TFA isomers. This information can then be used to construct a database and as a basis for meaningful recommendations. Practical applications: Areas that require further investigations have been identified: 1) Establish a uniform TFA nomenclature based on chemical structure. 2) Standardize, assess and normalize appropriate methodologies for the analysis of TFAs. 3) Synthesize pure reference standards for TFA identification. 4) Report total TFA levels with undesirable biological activities rather than total TFA content. 5) Assess the nutritional characteristics of individual TFAs independent of their origin. 6) Develop strategies to increase the content of desirable TFA isomers in ruminants. 7) Identify potential bioactive trans metabolites produced from PUFAs in ruminants. 8) Develop labeling regulations based on specific chemical structures and physiological effects regardless of their origin. 9) Construct an accurate database complemented with specific surveys of ruminant product fatty acid (FA) composition that can be accessed by regulatory agencies to make appropriate TFA recommendations. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

News Article | February 21, 2017

VANCOUVER, British Columbia, Feb. 21, 2017 (GLOBE NEWSWIRE) -- Naturally Splendid Enterprises Ltd. ("Naturally Splendid") (FRANKFURT:50N)(TSX VENTURE:NSP)(OTC:NSPDF) is pleased to announce we will be presenting at FOODEX JAPAN 2017 from March 7-10.  FOODEX JAPAN is the largest annual food and beverage tradeshow in Asia and has been a highly successful trade event since its debut in 1976 serving Japan’s $585 billion food market and additional significant Asian markets.  Over 76,500 professional visitors attended FOODEX 2016, including over 9,000 from Korea, Taiwan, China, Thailand, and Hong Kong. Naturally Splendid will be presenting a wide range of products at FOODEX JAPAN, including; debuting their new division; NATERA ® CBD. -NATERA® CBD (Cannabidiol) - featuring a product line of capsules formulated with CBD. The capsules are 15 or 25 mg of Full Spectrum Hemp Extract with NO-THC and are manufactured using a BioAvailable Proprietary Formulation for Full & Fast Absorption. -NATERA® HEMP FOODS - retail division which includes; seeds, proteins and oils -NATERA® INGREDIENTS - bulk division which also includes HempOmega™ Naturally Splendid President Mr. J. Craig Goodwin states, “We have been working diligently in developing a solid business strategy for CBD based products. The regulatory environment regarding CBD products continues to evolve, creating opportunities for Naturally Splendid in the region.  For our initial CBD product, the Company has negotiated an exclusive sales agreement for Japan with an established manufacturer of exceptional quality CBD capsules. We are currently evaluating and finalizing several other CBD related products, some of which may be included in the debut of NATERA ® CBD in Japan”. Naturally Splendid CEO Mr. Dave Eto states, “As part of our Strategic Plan, we have restructured our branding under the NATERA™ banner; thus, we will build a stronger presence in various multiple geographical  territories. I am particularly encouraged with our new division NATERA® CBD and the emerging opportunities it brings. I will personally be attending JAPAN TRADEX with Craig Goodwin and we will be investigating multiple opportunities for NATERA® CBD and HempOmega™.” Naturally Splendid will be presenting with Eat Real Snack Foods at JAPAN FOODEX who are participating as Canadian Delegates in the Canadian Pavilion. Naturally Splendid recently completed an acquisition of a comprehensive state-of–the-art packaging line from Eat Real Snack Foods and continues to develop business opportunities between the Companies.  JAPAN FOODEX is indicative of the potential synergies between the companies. According to Agriculture and Agri Food Canada; - Japanese packaged food sales were valued at US$158 billion in 2015, and are anticipated to reach US$164.2 billion by 2020. - Japanese consumers are renowned for placing enormous importance on consuming food that is both safe and of  high-quality, and they perceive Canada as a country that produces food with these characteristics. Japan is a trendsetter in many areas, and it can be a very useful gateway to other markets within Asia. Naturally Splendid has granted 60,000 stock options to a consultant.  The options were granted for a period of five (5) years, expiring on February 13, 2022. The stock options will vest over two years and each stock option will allow the holder to purchase a common share of Naturally Splendid at an exercise price of $0.35. Naturally Splendid is a multifaceted biotechnology company that is developing, producing, commercializing, and licensing an entirely new generation of plant-derived, bioactive ingredients, nutrient dense foods, and related products. Naturally Splendid is building an expanding portfolio of patents (issued and pending) and proprietary intellectual property focused on the commercial uses of industrial hemp and non-psychoactive cannabinoid compounds in a broad spectrum of applications. Naturally Splendid currently has six innovative divisions: (1) Natera® brand of retail hemp superfood products currently distributed throughout North America and Asia; (2) Chi Hemp Industries Incorporated (Chii) is selling natural and organic hemp products through e-commerce (3) PawsitiveFX® brand of pet care products; (4) Simpli Plant-Based Ingredients Division of plant-derived bulk ingredients including patent-pending HempOmega®; (5) The 12,000-square-foot POS / BPC Facility - which is managed for Naturally Splendid by POS Bio-Sciences - is positioned to offer commercial-scale custom processing solutions for biological materials, such as functional foods and natural health ingredients to a wide range of clients (6) hemp-based cannabinoid nutraceuticals. Naturally Splendid's advanced technologies, industry expertise, and strategic partners allow for the creation of customized solutions with a consistent focus on quality and sustainability. For more information e-mail or call Investor Relations at 604-673-9573. On Behalf of the Board of Directors Mr. Dave Eto  CEO, Director Information set forth in this news release contains forward-looking statements that are based on assumptions as of the date of this news release. These statements reflect management's current estimates, beliefs, intentions and expectations. They are not guarantees of future performance. Naturally Splendid cautions that all forward looking statements are inherently uncertain and that actual performance may be affected by a number of material factors, many of which are beyond Naturally Splendid's control including, the Naturally Splendid's ability to compete with large food and beverage companies; sales of any potential products developed will be profitable; sales of shelled hemp seed will continue at existing rates or increase; the ability to complete the sales of all bulk hemp seed purchase orders; and the risk that any of the potential applications may not receive all required regulatory or legal approval. Accordingly, actual and future events, conditions and results may differ materially from the estimates, beliefs, intentions and expectations expressed or implied in the forward looking information. Except as required under applicable securities legislation, Naturally Splendid undertakes no obligation to publicly update or revise forward-looking information. NEITHER TSX VENTURE EXCHANGE NOR ITS REGULATION SERVICES PROVIDER (AS THAT TERM IS DEFINED IN THE POLICIES OF THE TSX VENTURE EXCHANGE) ACCEPTS RESPONSIBILITY FOR THE ADEQUACY OR ACCURACY OF THIS RELEASE.

Malhi S.S.,Agriculture and Agri Food Canada | Nyborg M.,University of Alberta | Goddard T.,Alberta Agriculture and Rural Development | Puurveen D.,University of Alberta
Nutrient Cycling in Agroecosystems | Year: 2011

Soil, crop and fertilizer management practices may affect the amount and quality of organic C and N in soil. A long-term field experiment (growing barley, wheat, or canola) was conducted on a Black Chernozem (Albic Argicryoll) loam at Ellerslie, Alberta, Canada, to determine the influence of 19 (1980 to 1998) or 27 years (1980 to 2006) of tillage (zero tillage [ZT] and conventional tillage [CT]), straw management (straw removed [S Rem]and straw retained [S Ret]) and N fertilizer rate (0, 50 and 100 kg N ha -1 in S Ret and 0 kg N ha -1 in S Rem plots) on total organic C (TOC) and N (TON), and light fraction organic C (LFOC) and N (LFON) in the 0-7.5 and 7.5-15 cm or 0-5, 5-10 and 10-15 cm soil layers. The mass of TOC and TON in soil was usually higher in S Ret than in S Rem treatment (by 3.44 Mg C ha -1 for TOC and 0.248 Mg N ha -1 for TON after 27 years), but there was little effect of tillage and N fertilization on these parameters. The mass of LFOC and LFON in soil tended to increase with S Ret (by 285 kg C ha -1 for LFOC and 12.6 kg N ha -1 for LFON with annual rate of 100 kg N ha -1 for 27 years) , increased with N fertilizer application (by 517 kg C ha -1 for LFOC and 36.0 kg N ha -1 for LFON after 27 years), but was usually higher under CT than ZT (by 451 kg C ha -1 for LFOC and 25.3 kg N ha -1 for LFON after 27 years). Correlations between soil organic C or N fractions were highly significant in most cases. Linear regressions between crop residue C input and soil organic C or N were significant in most cases. The effects of tillage, straw management and N fertilizer on soil were more pronounced for LFOC and LFON than TOC and TON, and also in the surface layers than in the deeper layers. Tillage and straw management had little or no effect on C:N ratios, but the C:N ratios in light organic fractions significantly decreased with increasing N rate (from 20. 06 at zero-N to 18. 91 at 100 kg N ha -1). Compared to the 1979 results, in treatments that did not receive N fertilizer (CTS Rem0, CTS Ret0, ZTS Rem0 and ZTS Ret0), CTS Rem0 resulted in a net decrease in TOC concentration (by 1.9 g C kg -1) in the 0-15 cm soil layer in 2007 (after 27 years), with little or no change in the CTS Ret0 and ZTS Rem0 treatments, while there was a net increase in TOC concentration (by 1.2 g C kg -1) in the ZTS Ret0 treatment. Straw retention and N fertilizer application at 50 and 100 kg N ha -1 rates showed a net positive effect on TOC concentration under both ZT (ZTS Ret50 by 2.3 g C kg -1 and ZTS Ret100 by 3.1 g C kg -1) and CT (CTS Ret50 by 3.5 g C kg -1 and CTS Ret100 by 1.6 g C kg -1) treatments in 2007 compared to 1979 data. In conclusion, the findings suggest that retention of straw, application of N fertilizer and elimination of tillage would improve soil quality, and this might increase the potential for N supplying power of the soil and sustainability of crop productivity. © 2011 Springer Science+Business Media B.V.

Ragupathy R.,Agriculture and Agri Food Canada | Rathinavelu R.,Research and Development Center | Cloutier S.,Agriculture and Agri Food Canada | Cloutier S.,University of Manitoba
BMC Genomics | Year: 2011

Background: Flax (Linum usitatissimum L.) is an important source of oil rich in omega-3 fatty acids, which have proven health benefits and utility as an industrial raw material. Flax seeds also contain lignans which are associated with reducing the risk of certain types of cancer. Its bast fibres have broad industrial applications. However, genomic tools needed for molecular breeding were non existent. Hence a project, Total Utilization Flax GENomics (TUFGEN) was initiated. We report here the first genome-wide physical map of flax and the generation and analysis of BAC-end sequences (BES) from 43,776 clones, providing initial insights into the genome.Results: The physical map consists of 416 contigs spanning ~368 Mb, assembled from 32,025 fingerprints, representing roughly 54.5% to 99.4% of the estimated haploid genome (370-675 Mb). The N50 size of the contigs was estimated to be ~1,494 kb. The longest contig was ~5,562 kb comprising 437 clones. There were 96 contigs containing more than 100 clones. Approximately 54.6 Mb representing 8-14.8% of the genome was obtained from 80,337 BES. Annotation revealed that a large part of the genome consists of ribosomal DNA (~13.8%), followed by known transposable elements at 6.1%. Furthermore, ~7.4% of sequence was identified to harbour novel repeat elements. Homology searches against flax-ESTs and NCBI-ESTs suggested that ~5.6% of the transcriptome is unique to flax. A total of 4064 putative genomic SSRs were identified and are being developed as novel markers for their use in molecular breeding.Conclusion: The first genome-wide physical map of flax constructed with BAC clones provides a framework for accessing target loci with economic importance for marker development and positional cloning. Analysis of the BES has provided insights into the uniqueness of the flax genome. Compared to other plant genomes, the proportion of rDNA was found to be very high whereas the proportion of known transposable elements was low. The SSRs identified from BES will be valuable in saturating existing linkage maps and for anchoring physical and genetic maps. The physical map and paired-end reads from BAC clones will also serve as scaffolds to build and validate the whole genome shotgun assembly. © 2011 Ragupathy et al; licensee BioMed Central Ltd.

Yang X.,University of South China | Song J.,Agriculture and Agri Food Canada | Campbell-Palmer L.,Agriculture and Agri Food Canada | Fillmore S.,Agriculture and Agri Food Canada | Zhang Z.,University of South China
Postharvest Biology and Technology | Year: 2013

Ethylene plays an important role in regulating fruit ripening and senescence and directly influences the development of the eating quality of fresh apples, including appearance, color, texture, and flavor. Apple fruit (Malus domestica Borkh.) is a well-known climacteric fruit and a good model system to study fruit ripening and senescence. To better understand fruit ripening and the role of ethylene perception and signal transduction, apples harvested at a pre-climacteric stage were allowed to naturally ripen, or ripening was either stimulated by treatment with 36μLL-1 ethylene for 24h or inhibited by 1-MCP treatment (1.0μLL-1 for 24h), respectively. Postharvest physiological indices including respiration and ethylene production were monitored for 22d for ethylene treatment and 47d for 1-MCP treatment. Based on an efficiency test, 20 genes in relation to ethylene biosynthesis and perception were investigated using real-time qPCR during the post-treatment period. The ETR2, ETR5, ERSs, EIL4, ERFs genes together with ACS1 and ACO1 genes were significantly up-regulated in fruit during ripening. Ethylene treatment further enhanced the expression of ACO2, ETR1, CTR1s and EIN2A genes, while the ACS3 and ACO3, and EIN2B genes were only slightly affected. 1-MCP treatment significantly inhibited expression of ACS1, ACO1 and ACO2 ethylene biosynthesis genes, which coincided with ethylene production. 1-MCP treatment also reduced expression of ETR1, ETR2, ETR5, ERSs, CTR1, EIN2A, EIL4 and ERFs genes, while having a limited effect on ACS3, ACO3, and EIN2B. This study demonstrated the complexity and dynamic changes of transcriptional profiles of ethylene perception and biosynthesis in response to fruit ripening, ethylene, and 1-MCP treatment. Understanding of the significant changes of these genes and their function may help to explore the mechanisms controlling apple fruit ripening and its response to exogenous ethylene stimuli and action inhibition at the receptor level during ripening and senescence. © 2012.

Zhang L.,Agriculture and Agri Food Canada | Chen H.,Agriculture and Agri Food Canada | Brandizzi F.,Michigan State University | Verchot J.,Oklahoma State University | Wang A.,Agriculture and Agri Food Canada
PLoS Genetics | Year: 2015

The unfolded protein response (UPR) signaling network encompasses two pathways in plants, one mediated by inositol-requiring protein-1 (IRE1)-bZIP60 mRNA and the other by site-1/site-2 proteases (S1P/S2P)-bZIP17/bZIP28. As the major sensor of UPR in eukaryotes, IRE1, in response to endoplasmic reticulum (ER) stress, catalyzes the unconventional splicing of HAC1 in yeast, bZIP60 in plants and XBP1 in metazoans. Recent studies suggest that IRE1p and HAC1 mRNA, the only UPR pathway found in yeast, evolves as a cognate system responsible for the robust UPR induction. However, the functional connectivity of IRE1 and its splicing target in multicellular eukaryotes as well as the degree of conservation of IRE1 downstream signaling effectors across eukaryotes remains to be established. Here, we report that IRE1 and its substrate bZIP60 function as a strictly cognate enzyme-substrate pair to control viral pathogenesis in plants. Moreover, we show that the S1P/S2P-bZIP17/bZIP28 pathway, the other known branch of UPR in plants, does not play a detectable role in virus infection, demonstrating the distinct function of the IRE1-bZIP60 pathway in plants. Furthermore, we provide evidence that bZIP60 and HAC1, products of the enzyme-substrate duet, rather than IRE1, are functionally replaceable to cope with ER stress in yeast. Taken together, we conclude that the downstream signaling of the IRE1-mediated splicing is evolutionarily conserved in yeast and plants, and that the IRE1-bZIP60 UPR pathway not only confers overlapping functions with the other UPR branch in fundamental biology but also may exert a unique role in certain biological processes such as virus-plant interactions. © 2015 Zhang et al.

Hugelius G.,University of Stockholm | Tarnocai C.,Agriculture and Agri Food Canada | Broll G.,University of Osnabrück | Canadell J.G.,CSIRO | And 2 more authors.
Earth System Science Data | Year: 2013

High-latitude terrestrial ecosystems are key components in the global carbon (C) cycle. Estimates of global soil organic carbon (SOC), however, do not include updated estimates of SOC storage in permafrost-affected soils or representation of the unique pedogenic processes that affect these soils. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify the SOC stocks in the circumpolar permafrost region (18.7 × 106 km2). The NCSCD is a polygon-based digital database compiled from harmonized regional soil classification maps in which data on soil order coverage have been linked to pedon data (n Combining double low line 1778) from the northern permafrost regions to calculate SOC content and mass. In addition, new gridded datasets at different spatial resolutions have been generated to facilitate research applications using the NCSCD (standard raster formats for use in geographic information systems and Network Common Data Form files common for applications in numerical models). This paper describes the compilation of the NCSCD spatial framework, the soil sampling and soil analytical procedures used to derive SOC content in pedons from North America and Eurasia and the formatting of the digital files that are available online. The potential applications and limitations of the NCSCD in spatial analyses are also discussed.©Author(s) 2013.

He Y.,National Research Council Canada | Hou L.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Wang H.,Agriculture and Agri Food Canada | Hu K.,China Agricultural University | McConkey B.,Agriculture and Agri Food Canada
Scientific Reports | Year: 2014

Soil surface texture is an important environmental factor that influences crop productivity because of its direct effect on soil water and complex interactions with other environmental factors. Using 30-year data, an agricultural system model (DSSAT-CERES-Wheat) was calibrated and validated. After validation, the modelled yield and water use (WU) of spring wheat (Triticum aestivum L.) from two soil textures (silt loam and clay) under rain-fed condition were analyzed. Regression analysis showed that wheat grown in silt loam soil is more sensitive to WU than wheat grown in clay soil, indicating that the wheat grown in clay soil has higher drought tolerance than that grown in silt loam. Yield variation can be explained by WU other than by precipitation use (PU). These results demonstrated that the DSSAT-CERES-Wheat model can be used to evaluate the WU of different soil textures and assess the feasibility of wheat production under various conditions. These outcomes can improve our understanding of the long-term effect of soil texture on spring wheat productivity in rain-fed condition.

Gao Z.,Agricultural University of Hebei | Yuan H.,Agricultural University of Hebei | Ma W.,Agricultural University of Hebei | Liu X.,China Agricultural University | Desjardins R.L.,Agriculture and Agri Food Canada
Environmental Pollution | Year: 2011

Accurately determining methane emission factors of dairy herd in China is imperative because of China's large population of dairy cattle. An inverse dispersion technique in conjunction with open-path lasers was used to quantify methane emissions from a dairy feedlot during the fall and winter seasons in 2009-2010. The methane emissions had a significant diurnal pattern during both periods with three emission peaks corresponding to the feeding schedule. A 10% greater emission rate in the fall season was obtained most likely by the higher methane emission from manure during that period. An annual methane emission rate of 109 ± 6.7 kg CH4 yr-1 characterized with a methane emission intensity of 32.3 ± 1.59 L CH4 L-1 of milk and a methane conversion factor (Ym) of 7.3 ± 0.38% for mature cattle was obtained, indicating the high methane emission intensity and low milk productivity in Northern China. © 2011 Elsevier Ltd. All rights reserved.

Nicolai T.,University of Maine, France | Britten M.,Agriculture and Agri Food Canada | Schmitt C.,Nestlé
Food Hydrocolloids | Year: 2011

The literature is reviewed on the formation and the structure of β-lactoglobulin and whey protein isolate (WPI) aggregates in aqueous solution induced by heating. The focus is on the effects of the pH and added salt. The use of β-lactoglobulin and WPI aggregates in cold-set gels, foams and emulsions, encapsulation, and films and coatings is also reviewed. © 2011 Elsevier Ltd.

Beaulieu A.D.,Prairie Swine Center Inc. | Aalhus J.L.,Agriculture and Agri Food Canada | Williams N.H.,PIC | Patience J.F.,Prairie Swine Center Inc. | Patience J.F.,Iowa State University
Journal of Animal Science | Year: 2010

The objective of this study was to investigate the relationships among birth weight, birth order, or litter size on growth performance, carcass quality, and eating quality of the ultimate pork product. Data were collected from 98 pig litters and, with the addition of recording birth weight and birth order, farrowing and piglet management were according to normal barn practices. In the nursery and during growout, the pigs received the normal feeding program for the barn and, with the addition of individual tattooing, were marketed as per standard procedure. From 24 litters, selected because they had at least 12 pigs born alive and represented a range of birth weights, 4 piglets were chosen (for a total of 96 piglets) and sent to Agriculture and Agri-Food Canada-Lacombe Research Centre (Lacombe, Alberta, Canada) when they reached 120 kg for extensive meat quality and sensory analysis. Individual BW was measured at birth, on the day of weaning, 5 wk after weaning, at nursery exit, at first pull, and at the time of marketing. Litter sizes were divided into 3 categories: small (3 to 10 piglets), medium (11 to 13 piglets), and large (14 to 19 piglets). There were 4 birth-weight quartiles: 0.80 to 1.20, 1.25 to 1.45, birth weight, carcass quality, 1.50 to 1.70, and 1.75 to 2.50 kg. Increased litter size resulted in reduced mean birth weight (P < 0.05), but had no effect on within litter variability or carcass quality (P > 0.05) when slaughtered at the same endpoint. Lighter birth-weight pigs had reduced BW at weaning, 5 and 7 wk postweaning, and at first pull and had increased days to market (P < 0.05). Birth weight had limited effects on carcass quality, weight of primal cuts, objective quality, and overall palatability of the meat at the same slaughter weight (P > 0.05). In conclusion, increased litter size resulted in decreased mean birth weight but no change in days to market. Lighter birth-weight pigs took longer to reach market. Despite some differences in histological properties, birth weight had limited effects on carcass composition or final eating quality of the pork when slaughtered at the same BW and large litter size resulted in more pigs weaned and marketed compared with the smaller litters. We concluded that based on the conditions of this study, other than increased days to market, there is no reason based on pig performance or pork quality to slow down the goal of the pork industry to increase sow productivity as a means to increase efficiency. © 2010 American Society of Animal Science.

Bykova N.V.,Agriculture and Agri Food Canada | Moller I.M.,University of Aarhus | Gardestrom P.,Umeå University | Igamberdiev A.U.,Memorial University of Newfoundland
Mitochondrion | Year: 2014

Oxidation of glycine in photorespiratory pathway is the major flux through mitochondria of C3 plants in the light. It sustains increased intramitochondrial concentrations of NADH and NADPH, which are required to engage the internal rotenone-insensitive NAD(P)H dehydrogenases and the alternative oxidase. We discuss here possible mechanisms of high photorespiratory flux maintenance in mitochondria and suggest that it is fulfilled under conditions where the concentrations of glycine decarboxylase reaction products NADH and CO2 achieve an equilibrium provided by malate dehydrogenase and carbonic anhydrase, respectively. This results in the removal of these products from the glycine decarboxylase multienzyme active sites and in the maintenance of their concentrations at levels sufficiently low to prevent substrate inhibition of the reaction. © 2014 Elsevier B.V.

Zahiri R.,University of Turku | Kitching I.J.,Natural History Museum in London | Lafontaine J.D.,Agriculture and Agri Food Canada | Mutanen M.,University of Oulu | And 3 more authors.
Zoologica Scripta | Year: 2011

To examine the higher level phylogeny and evolutionary affinities of the megadiverse superfamily Noctuoidea, an extensive molecular systematic study was undertaken with special emphasis on Noctuidae, the most controversial group in Noctuoidea and arguably the entire Lepidoptera. DNA sequence data for one mitochondrial gene (cytochrome oxidase subunit I) and seven nuclear genes (Elongation Factor-1α, wingless, Ribosomal protein S5, Isocitrate dehydrogenase, Cytosolic malate dehydrogenase, Glyceraldehyde-3-phosphate dehydrogenase and Carbamoylphosphate synthase domain protein) were analysed for 152 taxa of principally type genera/species for family group taxa. Data matrices (6407bp total) were analysed by parsimony with equal weighting and model-based evolutionary methods (maximum likelihood), which revealed a new high-level phylogenetic hypothesis comprising six major, well-supported lineages that we here interpret as families: Oenosandridae, Notodontidae, Erebidae, Nolidae, Euteliidae and Noctuidae. © 2010 The Authors. Zoologica Scripta © 2010 The Norwegian Academy of Science and Letters.

Hannoufa A.,Agriculture and Agri Food Canada | Hossain Z.,Environmental Proteomics NB Inc
Biocatalysis and Agricultural Biotechnology | Year: 2012

Carotenoids are plant secondary metabolites with a range of beneficial physiological, health and industrial traits. In this review, we summarize the carotenoid biosynthesis pathway and provide an update on research into its regulation in plants. We discuss some factors that determine the steady-state levels of carotenoids in different plant organs and tissues. These factors include the flux through the biosynthesis pathway, and how certain steps represent rate-limiting (bottlenecks), that were exploited in the metabolic engineering of carotenoids. In addition, we discuss carotenoid catabolism, storage and sequestration, and transcriptional and epigenetic regulation as factors affecting the rate of carotenoid accumulation. © 2012.

Zahiri R.,University of Turku | Holloway J.D.,Natural History Museum in London | Kitching I.J.,Natural History Museum in London | Lafontaine J.D.,Agriculture and Agri Food Canada | And 2 more authors.
Systematic Entomology | Year: 2012

As a step towards understanding the higher-level phylogeny and evolutionary affinities of quadrifid noctuoid moths, we have undertaken the first large-scale molecular phylogenetic analysis of the moth family Erebidae, including almost all subfamilies, as well as most tribes and subtribes. DNA sequence data for one mitochondrial gene (COI) and seven nuclear genes (EF-1α, wingless, RpS5, IDH, MDH, GAPDH and CAD) were analysed for a total of 237 taxa, principally type genera of higher taxa. Data matrices (6407 bp in total) were analysed by parsimony with equal weighting and model-based evolutionary methods (maximum likelihood), which revealed a well-resolved skeleton phylogenetic hypothesis with 18 major lineages, which we treat here as subfamilies of Erebidae. We thus present a new phylogeny for Erebidae consisting of 18 moderate to strongly supported subfamilies: Scoliopteryginae, Rivulinae, Anobinae, Hypeninae, Lymantriinae, Pangraptinae, Herminiinae, Aganainae, Arctiinae, Calpinae, Hypocalinae, Eulepidotinae, Toxocampinae, Tinoliinae, Scolecocampinae, Hypenodinae, Boletobiinae and Erebinae. Where possible, each monophyletic lineage is diagnosed by autapomorphic morphological character states, and within each subfamily, monophyletic tribes and subtribes can be circumscribed, most of which can also be diagnosed by morphological apomorphies. All additional taxa sampled fell within one of the four previously recognized quadrifid families (mostly into Erebidae), which are now found to include two unusual monobasic taxa from New Guinea: Cocytiinae (now in Erebidae: Erebinae) and Eucocytiinae (now in Noctuidae: Pantheinae). © 2011 The Authors. Systematic Entomology © 2011 The Royal Entomological Society.

Xutian S.,Canadian Institute of Complementary and Alternative Medicine Research | Cao D.,Academy of Chinese Medicine Research of Hebei Province | Wozniak J.,Psychology Clinic | Junion J.,AdvanceMed Corporation | Boisvert J.,Agriculture and Agri Food Canada
American Journal of Chinese Medicine | Year: 2012

Traditional Chinese Medicine (TCM) has made great contributions to human history, especially in China, as has been recorded for thousands of years. The characteristics of TCM in both theory and practice make it different from Conventional Western Medicine (CWM). The characteristics of TCM include phenomenological, philosophical, and methodological aspects. This paper briefly discusses some historical turning points and innovations in TCM development in China, explores human body enigmas such as the heart, compares different aspects of TCM and CWM, and identifies the unique characteristics of TCM treatment, as compared to other medical systems. © 2012 World Scientific Publishing Company & Institute for Advanced Research in Asian Science and Medicine.

Champagne C.P.,Agriculture and Agri Food Canada | Raymond Y.,Agriculture and Agri Food Canada | Simon J.-P.,Eurobiotec Brussels
Applied Microbiology and Biotechnology | Year: 2012

Probiotic cultures of Lactobacillus plantarum, Lactobacillus rhamnosus, Bifidobacterium longum, Lactobacillus casei and Lactobacillus acidophilus were grown in media having water activities (a w) adjusted between 0.99 and 0.94 with NaCl or with a mixture of glycerol and sucrose in order to find conditions of osmotic stress which would still allow for good growth. Cultures grown at a w00.96 or 0.99 were then recovered by centrifugation, added to a sucrose- phosphate medium and air-dried. In some assays, a 2-h osmotic stress was applied to the cell concentrate prior to air-drying. Assays were also carried out where betaine, glutamate and proline (BGP) supplements were added as protective compounds to the growth or drying media. For most strains, evidence of osmotic stress and benefits of BGP supplementation on growth occurred at a w00.96. Growing the cells in complex media adjusted at a w00.96 did not enhance their subsequent survival to air-drying, but applying the 2-h osmotic stress did. Addition of the BGP supplements to the growth medium or in the 2-h stress medium did not enhance survival to air-drying. Furthermore, addition of BGP to a sucrose-phosphate drying medium reduced survival of the cultures to air-drying. This study provides preliminary data for producers of probiotics who wish to use air-drying in replacement of freeze-drying for the stabilization of cultures. © Springer-Verlag 2011.

Kasuga T.,Crops Pathology and Genetics Research Unit | Gijzen M.,Agriculture and Agri Food Canada
Trends in Microbiology | Year: 2013

A feature of pathogenic and invasive organisms is their adaptability when confronted with host and environmental challenges. Recent studies have demonstrated that plant pathogens rely on epigenetic processes for this purpose. Epiallelic variation of effector genes that results in evasion of host immunity is one emerging phenomenon. Another is the epigenetically induced reprogramming and diversification of transcriptional patterns by de-repression of transposable elements. These observations indicate that epigenetic control of gene expression provides a versatile means of generating phenotypic diversity that is adaptable and heritable across generations. © 2013 .

Humada M.J.,Research Center rmacion Agrarias Cifa | Serrano E.,Research Center rmacion Agrarias Cifa | Sanudo C.,University of Zaragoza | Rolland D.C.,Agriculture and Agri Food Canada | Dugan M.E.R.,Agriculture and Agri Food Canada
Meat Science | Year: 2012

Thirty-three young bulls from Tudanca local breed were used to investigate the effect of two production systems (semi-extensive vs. intensive) and two slaughter ages (12 vs. 14. months) on meat fatty acid (FA) composition. Longissimus thoracis from semi-extensive animals had a lower percentage of intramuscular fat (p≤ 0.001), saturated FAs (p≤ 0.05), trans-18:1 (p≤ 0.001), n-6/n-3 ratio (p≤ 0.001) and a higher percentage of branched chain FAs (p≤ 0.001), polyunsaturated FAs (p≤ 0.001) and conjugated linoleic acid (CLA) (p≤ 0.001). Few differences were observed in FA composition between slaughter ages. Hence, meat from semi-extensive animals slaughtered at 12 or 14. months displayed a healthier FA profile from a consumer's point of view. © 2011 Elsevier Ltd.

Campos-Vega R.,Autonomous University of Queretaro | Loarca-Pina G.,Autonomous University of Queretaro | Oomah B.D.,Agriculture and Agri Food Canada
Food Research International | Year: 2010

Pulses contain a number of bioactive substances including enzyme inhibitors, lectins, phytates, oligosaccharides, and phenolic compounds. Enzyme inhibitors can diminish protein digestibility, and lectins can reduce nutrient absorption, but both have little effect after cooking. Phytic acid can diminish mineral bioavailability. Some phenolic compounds can reduce protein digestibility and mineral bioavailability, and galactooligosaccharides may cause flatulence. On the other hand, these same compounds may have protective effects. Phytic acid exhibits antioxidant activity and protects DNA damage, phenolic compounds have antioxidant and other important physiological and biological properties, and galactooligosaccharides may elicit prebiotic activity. These compounds can have complementary and overlapping mechanisms of action, including modulation of detoxifying enzymes, stimulation of the immune system, regulation of lipid and hormone metabolism, antioxidant, antimutagen, and antiangiogenic effects, reduction of tumor initiation, and promotion and induction of apoptosis. Secondary metabolites are considerated antinutrients, simultaneously conferring health benefits, so these secondary metabolites are currently marketed as functional foods and nutraceuticals ingredients. © 2009.

Lin S.,Wuhan University of Technology | Huang J.,Wuhan University of Technology | Chang P.R.,Agriculture and Agri Food Canada | Wei S.,Wuhan University of Technology | And 2 more authors.
Carbohydrate Polymers | Year: 2013

New nanocomposites consisting of a castor oil-based polyurethane matrix filled with acetylated cellulose nanocrystals (ACNs) were developed. The ACN exhibited improved dispersion in tetrahydrofuran as a blending medium, and reduced polarity as compared with unmodified cellulose nanocrystals, resulting in a high loading level of 25 wt% in the nanocomposite. As the ACN loading-level increased from 0% to 25%, the tensile strength and Young's modulus of the nanocomposites increased from 2.79 MPa to 10.41 MPa and from 0.98 MPa to 42.61 MPa, respectively. When the ACN loading-level was 10 wt%, the breaking elongation of the nanocomposites reached the maximum value of more than twice that of the polyurethane. The enhanced mechanical performance was primarily attributed to the formation of a three-dimensional ACN network and strong interfacial interactions between filler and matrix. This work produced new polyurethane-based nanocomposites containing modified cellulose nanocrystal with a high biomass content. Its high performance could contribute to potential applications.

Lafond G.P.,Agriculture and Agri Food Canada | Walley F.,University of Saskatchewan | May W.E.,Agriculture and Agri Food Canada | Holzapfel C.B.,Indian Head Agricultural Research Foundation
Soil and Tillage Research | Year: 2011

Meeting the needs of an increasing population requires protection of our arable land base and improvements in productivity. The study compared soil quality characteristics and crop yield to nitrogen (N) fertilizer in two adjacent fields; one field managed with no-till for 31 years while the other for 9 years. In 2003, the two fields along with native prairie were sampled for soil quality parameters across two landscape positions. A small plot study involving five rates of urea N (0, 30, 60 90 and 120kgNha -1) and two phosphorus fertilizer placement methods (seed-placed vs side-banded) was conducted on the two adjacent fields for the period 2002-2009. The rates of N were superimposed on the same plots each year whereas wheat and canola were normally grown in alternate years. An N balance was conducted after 8 years to account for inputs and outputs of N. Soil bulk density values were 0.98gcm -3 for native prairie and 1.46 for LTNT and STNT in the 0-15cm soil layer. The native prairie had 48.2tha -1of SOC vs 44.4 and 36.7 for LTNT and STNT, respectively, in the 0-15cm soil layer and no detectable differences for the 15-30cm soil layer in 2003. Potentially mineralizable N using the Hot KCl digestion in the 0-15cm soil layer was 60kgha -1 of ammonium nitrogen for native prairie and 30 and 22kgha -1 for LTNT and STNT, respectively. For amino sugar-N, native prairie had 558kgha -1 vs 462 and 370kgha -1 for the LTNT and STNT, respectively. This indicates a positive relationship between SOC levels measured and potentially mineralizable N reflecting differences in land management. Phosphorus fertilizer placed in the side-band with N yielded 3.5% more than seed-placed phosphorus in spring wheat and no difference in canola. Grain yields were 14% and 16% more for LTNT than STNT in spring wheat and canola, respectively. Maximum grain N removal averaged in wheat was 87kgha -1 for LTNT and 74kgha -1 for STNT and 71 and 65.4kgha -1 in canola, respectively. A positive N balance was obtained provided that 60kgha -1 of N was applied every year and no accumulation of nitrate-N was noted even with rates that exceeded N removal in the grain. This supports the view that no-till combined with continuous cropping and proper fertility represents a path to sustaining the global soil resource. © 2011 Elsevier B.V.

Newell M.A.,Iowa State University | Cook D.,Iowa State University | Tinker N.A.,Agriculture and Agri Food Canada | Jannink J.-L.,Cornell University
Theoretical and Applied Genetics | Year: 2011

The level of population structure and the extent of linkage disequilibrium (LD) can have large impacts on the power, resolution, and design of genome-wide association studies (GWAS) in plants. Until recently, the topics of LD and population structure have not been explored in oat due to the lack of a high-throughput, high-density marker system. The objectives of this research were to survey the level of population structure and the extent of LD in oat germplasm and determine their implications for GWAS. In total, 1,205 lines and 402 diversity array technology (DArT) markers were used to explore population structure. Principal component analysis and model-based cluster analysis of these data indicated that, for the lines used in this study, relatively weak population structure exists. To explore LD decay, map distances of 2,225 linked DArT marker pairs were compared with LD (estimated as r2). Results showed that LD between linked markers decayed rapidly to r2 = 0. 2 for marker pairs with a map distance of 1.0 centi-Morgan (cM). For GWAS, we suggest a minimum of one marker every cM, but higher densities of markers should increase marker-QTL association and therefore detection power. Additionally, it was found that LD was relatively consistent across the majority of germplasm clusters. These findings suggest that GWAS in oat can include germplasm with diverse origins and backgrounds. The results from this research demonstrate the feasibility of GWAS and related analyses in oat. © 2010 Springer-Verlag (outside the USA).

Kwit C.,University of Tennessee at Knoxville | Moon H.S.,University of Tennessee at Knoxville | Warwick S.I.,Agriculture and Agri Food Canada | Stewart C.N.,University of Tennessee at Knoxville
Trends in Biotechnology | Year: 2011

Incorporation of crop genes into wild and weedy relative populations (i.e. introgression) has long been of interest to ecologists and weed scientists. Potential negative outcomes that result from crop transgene introgression (e.g. extinction of native wild relative populations; invasive spread by wild or weedy hosts) have not been documented, and few examples of transgene introgression exist. However, molecular evidence of introgression from non-transgenic crops to their relatives continues to emerge, even for crops deemed low-risk candidates for transgene introgression. We posit that transgene introgression monitoring and mitigation strategies are warranted in cases in which transgenes are predicted to confer selective advantages and disadvantages to recipient hosts. The utility and consequences of such strategies are examined, and future directions provided. © 2011 Elsevier Ltd.

Danforth B.N.,Cornell University | Cardinal S.,Agriculture and Agri Food Canada | Praz C.,University of Neuchatel | Almeida E.A.B.,University of Sao Paulo | Michez D.,University of Mons
Annual Review of Entomology | Year: 2013

Our understanding of bee phylogeny has improved over the past fifteen years as a result of new data, primarily nucleotide sequence data, and new methods, primarily model-based methods of phylogeny reconstruction. Phylogenetic studies based on single or, more commonly, multilocus data sets have helped resolve the placement of bees within the superfamily Apoidea; the relationships among the seven families of bees; and the relationships among bee subfamilies, tribes, genera, and species. In addition, molecular phylogenies have played an important role in inferring evolutionary patterns and processes in bees. Phylogenies have provided the comparative framework for understanding the evolution of host-plant associations and pollen specialization, the evolution of social behavior, and the evolution of parasitism. In this paper, we present an overview of significant discoveries in bee phylogeny based primarily on the application of molecular data. We review the phylogenetic hypotheses family-by-family and then describe how the new phylogenetic insights have altered our understanding of bee biology. © 2013 by Annual Reviews. All rights reserved.

Luo M.,CAS South China Botanical Garden | Luo M.,National Taiwan University | Liu X.,National Taiwan University | Singh P.,National Taiwan University | And 3 more authors.
Biochimica et Biophysica Acta - Gene Regulatory Mechanisms | Year: 2012

Sensing environmental changes and initiating a gene expression response are important for plants as sessile autotrophs. The ability of epigenetic status to alter rapidly and reversibly could be a key component to the flexibility of plant responses to the environment. The involvement of epigenetic mechanisms in the response to environmental cues and to different types of abiotic stresses has been documented. Different environmental stresses lead to altered methylation status of DNA as well as modifications of nucleosomal histones. Understanding how epigenetic mechanisms are involved in plant response to environmental stress is highly desirable, not just for a better understanding of molecular mechanisms of plant stress response but also for possible application in the genetic manipulation of plants. In this review, we highlight our current understanding of the epigenetic mechanisms of chromatin modifications and remodeling, with emphasis on the roles of specific modification enzymes and remodeling factors in plant abiotic stress responses. This article is part of a Special Issue entitled: Plant gene regulation in response to abiotic stress. © 2011 Elsevier B.V.

Patton R.A.,Nittany Dairy Nutrition Inc. | Hristov A.N.,Pennsylvania State University | Lapierre H.,Agriculture and Agri Food Canada
Veterinary Clinics of North America - Food Animal Practice | Year: 2014

This article summarizes the current literature as regards metabolizable protein (MP) and essential amino acid (EAA) nutrition of dairy cattle. Emphasis has been placed on research since the publication of the National Research Council Nutrient Requirements of Dairy Cattle, Seventh Revised Edition (2001). Postruminal metabolism of EAA is discussed in terms of the effect on requirements. This article suggests methods for practical application of MP and EAA balance in milking dairy cows. © 2014 Elsevier Inc.

Stewart D.,James Hutton Institute | Kennedy A.,Agriculture and Agri Food Canada | Pavel A.,Morgan
British Journal of Nutrition | Year: 2014

Global interest in food policy is emerging in parallel with mounting challenges to the food supply and the rising prevalence of diet-related chronic health conditions. Some of the foundational elements of food policies are agricultural practices, finite resources, as well as economic burdens associated with a growing and ageing population. At the intersection of these interests is the need for policy synchronisation and a better understanding of the dynamics within local, regional and national government decision-making that ultimately affect the wellness of the populous and the safety, quality, affordability and quantity of the food supply. Policies, synchronised or not, need to be implemented and, for the food industry, this has seen a myriad of approaches with respect to condensing complex nutritional information and health claims. These include front and/or back of pack labelling, traffic light systems, etc. but in general there is little uniformity at the more regional and global scales. This translation of the nutritional and health-beneficial messages accompanying specific products to the consumer will undoubtedly be an area of intense activity, and hopefully interaction with policy makers, as the food industry continues to become a more global industry. Copyright © 2014 The Authors.

Liu J.,Agriculture and Agri Food Canada | Pattey E.,Agriculture and Agri Food Canada | Miller J.R.,York University | McNairn H.,Agriculture and Agri Food Canada | And 2 more authors.
Remote Sensing of Environment | Year: 2010

Crop descriptors, such as leaf area index, crop cover fraction, and leaf chlorophyll content, can be successfully estimated using appropriate spectral indices from the visible and near infrared spectral regions. However, these indices do not provide estimates of dry biomass, an important indicator of crop productivity. For estimating crop aboveground dry biomass and yield, this study developed an approach to integrate crop stressors and crop descriptors derived from optical remote sensing data with the Monteith radiation use efficiency model. Multi-temporal remote sensing data were acquired by the Compact Airborne Spectrographic Imager and the Landsat-5/7 Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM+) sensors to monitor the growth conditions of corn in the 2001 and 2006 growing seasons. The modified triangular vegetation index (MTVI2) derived from the remote sensing data was used to estimate the fraction of absorbed photosynthetically active radiation (fAPAR). A canopy structure dynamics model was then used to simulate the seasonal variation of fAPAR. Crop water stress was estimated from the near and shortwave infrared reflectance of the Landsat images for a dry period in the 2001 growing season. By estimating leaf chlorophyll content using the Transformed Chlorophyll Absorption in Reflectance Index (TCARI) in combination with the Optimized Soil Adjusted Vegetation Index (OSAVI), different levels of nitrogen content could be identified. For the two growing seasons, the aboveground dry biomass and yield were linearly related with the cumulative absorbed photosynthetically active radiation (APAR) using the Monteith radiation use efficiency model. The cumulative APAR accounted for 96% of the corn aboveground dry biomass variability and 72% of the yield variability. Biomass and yield variability were partly explained by the variations in crop water stress intensity, which was dependent on soil texture. The seasonal radiation use efficiency was stable over the 2 years and was about 3.9 g MJ- 1, with a confidence interval of 0.6 g MJ- 1 at the 95% confidence level. The assimilation of remotely sensed data into the radiation use efficiency model performed well for monitoring dry biomass accumulation and estimating corn yields. Crown Copyright © 2009.

Grant C.A.,Agriculture and Agri Food Canada | Mahli S.S.,Agriculture and Agri Food Canada | Karamanos R.E.,Viterra Inc.
Field Crops Research | Year: 2012

Canola or rapeseed (Brassica sp. L.) is a major oilseed, being grown on more than 31 million hectares worldwide. Rapeseed has a high concentration of S in its tissue and seed and a particularly high demand for S relative to its yield potential. Therefore, effective S management is an important part of rapeseed production. Sulfur deficiencies are becoming increasingly prevalent due to higher crop yields, decreasing aerial deposition of S and decreasing mineralization of S from soil organic matter. Seed yields of both open-pollinated and hybrid rapeseed are usually optimized with applications of 15-60kgSha -1 applied as sulfate, which can be applied effectively in the autumn or in the spring, and broadcast, banded or seed-placed, depending on the environment in which the crop is being grown. On coarse-textured soils in high-moisture areas, leaching of autumn-applied sulfate-S may reduce yield response as compared to spring-application. If deficiencies are observed during the growing season, application of sulfate-S as late as bolting to early flowering can be beneficial although yield will generally be lower than if the S had been available from the start of crop growth. Elemental S fertilizers need to oxidize to sulfate before they are available for crop uptake or leaching and will generally not supply sufficient available S to optimize rapeseed yield in the year of application, or possibly for several years, depending on the environmental conditions and the management practices used. Elemental S should be managed in a manner that increases particle dispersion and contact with soil microorganisms to hasten the oxidation process. Management of S fertilizer sources should consider both the short- and long-term impacts on crop yield, seed quality and economics of production. Soil testing to determine the requirements for S fertilizer is challenging due to the spatial and temporal variability in sulfate availability. Improved assessment of S availability needs to consider both the release of S from organic matter and the site-specific distribution of sulfate across the landscape. © 2012.

Latta R.G.,Dalhousie University | Gardner K.M.,Dalhousie University | Gardner K.M.,Agriculture and Agri Food Canada | Staples D.A.,Dalhousie University | Staples D.A.,York University
Genetics | Year: 2010

The genetic architecture of variation in evolutionary fitness determines the trajectory of adaptive change. We identified quantitative trait loci (QTL) affecting fitness in a mapping population of recombinant inbred lines (RILs) derived from a cross between moist- and dry- associated ecotypes of Avena barbata. We estimated fitness in 179 RILs in each of two natural environments in each of 4 years. Two loci account for over half of the variation in geometric mean fitness across environments. These loci are associated in repulsion phase in the wild ecotypes, suggesting the potential for strong transgressive segregation, but also show significant epistasis giving hybrid breakdown. This epistasis is the result of sharply lower fitness in only one of the recombinant genotypes, suggesting that the loci may contain synergistically acting mutations. Within each trial (year/site combination), we can explain less of the variation than for geometric mean fitness, but the two major loci are associated with variation in fitness in most environments. Tests for pleiotropic effects of QTL on fitness in different environments reveal that the same loci are under selection in all trials. Genotype-by-environment interactions are significant for some loci, but this reflects variation in the strength, not the direction of selection. Copyright © 2010 by the Genetics Society of America.

Liu X.,National Taiwan University | Yu C.-W.,National Taiwan University | Duan J.,CAS South China Botanical Garden | Luo M.,National Taiwan University | And 5 more authors.
Plant Physiology | Year: 2012

The molecular mechanism of how the histone deacetylase HDA6 participates in maintaining transposable element (TE) silencing in Arabidopsis (Arabidopsis thaliana) is not yet defined. In this study, we show that a subset of TEs was transcriptionally reactivated and that TE reactivation was associated with elevated histone H3 and H4 acetylation as well as increased H3K4Me3 and H3K4Me2 in hda6 mutants. Decreased DNA methylation of the TEs was also detected in hda6 mutants, suggesting that HDA6 silences the TEs by regulating histone acetylation and methylation as well as the DNA methylation status of the TEs. Similarly, transcripts of some of these TEs were also increased in the methyltransferase1 (met1) mutant, with decreased DNA methylation. Furthermore, H4 acetylation, H3K4Me3, H3K4Me2, and H3K36Me2 were enriched at the coregulated TEs in the met1 and hda6 met1 mutants. Protein-protein interaction analysis indicated that HDA6 physically interacts with MET1 in vitro and in vivo, and further deletion analysis demonstrated that the carboxyl-terminal region of HDA6 and the bromo-adjacent homology domain of MET1 were responsible for the interaction. These results suggested that HDA6 and MET1 interact directly and act together to silence TEs by modulating DNA methylation, histone acetylation, and histone methylation status. © 2011 American Society of Plant Biologists. All Rights Reserved.

Fernandez-Flores S.,National Autonomous University of Mexico | Fernandez-Triana J.L.,University of Guelph | Fernandez-Triana J.L.,Agriculture and Agri Food Canada | Martinez J.J.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia | Zaldivar-Riveron A.,National Autonomous University of Mexico
Molecular Ecology Resources | Year: 2013

The cosmopolitan Microgastrinae is probably the most diverse braconid subfamily of parasitoid wasps, yet its species diversity is far from being known. As part of a global initiative for DNA barcoding Microgastrinae species, here we show the results of a study that assessed the species richness of this subfamily in a Mexican tropical dry forest located in the Chamela region, near the Pacific coast of Jalisco. Barcoding sequences of a total of 551 microgastrine specimens were generated, corresponding to 238 haplotypes. Performance of two species delineation approaches, a 2% corrected pairwise distance criterion and the general mixed Yule-coalescent (GMYC) method, yielded 100 and 112 putative species, respectively, which belong to 13 genera. The species delimited by the above two approaches were mostly congruent with our morphospecies identification. Ten molecular operational taxonomic units (MOTUs) were split into twenty-two species by the GMYC approach. We found morphological differences between the GMYC species corresponding to three of these MOTUs. Thus, a total of 103 microgastrine species were confirmed for the region of study. Thirty-three species were only represented by males, and therefore, their generic assignment is only tentatively proposed. Fornicia, Dolichogenoidea, Distatrix, Glyptapanteles and Pholetesor represent new generic records for the Mexican territory. A new record for the country is also provided for the Diolcogaster-basimacula species group. Based on a comparison of nearly 20 000 barcoding sequences released for Microgastrinae from 75 countries, only five microgastrine species from Chamela were found to occur in other countries, four in Costa Rica and one in Canada and the United States. © 2013 John Wiley & Sons Ltd.

Shang W.,Wuhan University of Technology | Huang J.,Wuhan University of Technology | Luo H.,CAS Wuhan Institute of Physics and Mathematics | Chang P.R.,Agriculture and Agri Food Canada | And 2 more authors.
Cellulose | Year: 2013

Hydrophobic cellulose nanocrystals (CNs) have been prepared by grafting isocyanate-terminated castor oil, a kind of natural vegetable oil, onto their surface. The existence of castor oil component in the modified cellulose nanocrystals was verified by Fourier transform infrared spectroscopy, solid-state 13C NMR spectra and X-ray photoelectron spectroscopy. At the same time, X-ray diffraction and transmission electron micrographs further proved that the crystalline structure and large aspect ratio of cellulose nanocrystals were essentially preserved after chemical grafting. Furthermore, the surface of modified cellulose nanocrystals appeared to be hydrophobic as indicated by contact angle measurements. The value of the polar component of surface energy decreased from 21. 5 mJ/m2 to almost zero via grafting castor oil. These novel hydrophobic castor oil-grafted cellulose nanocrystals appear as valuable alternatives to formulate bionanocomposites with non-polar polymers for optimized performances. © 2012 Springer Science+Business Media Dordrecht.

Cardinal S.,Agriculture and Agri Food Canada | Danforth B.N.,Cornell University
Proceedings of the Royal Society B: Biological Sciences | Year: 2013

Reliable estimates on the ages of the major bee clades are needed to further understand the evolutionary history of bees and their close association with flowering plants. Divergence times have been estimated for a few groups of bees, but no study has yet provided estimates for all major bee lineages. To date the origin of bees and their major clades, we first perform a phylogenetic analysis of bees including representatives from every extant family, subfamily and almost all tribes, using sequence data from seven genes. We then use this phylogeny to place 14 time calibration points based on information from the fossil record for an uncorrelated relaxed clock divergence time analysis taking into account uncertainties in phylogenetic relationships and the fossil record. We explore the effect of placing a hard upper age bound near the root of the tree and the effect of different topologies on our divergence time estimates. We estimate that crown bees originated approximately 123 Ma (million years ago) (113 - 132 Ma), concurrently with the origin or diversification of the eudicots, a group comprising 75 per cent of angiosperm species. All of the major bee clades are estimated to have originated during the Middle to Late Cretaceous, which is when angiosperms became the dominant group of land plants. © 2013 The Author(s) Published by the Royal Society. All rights reserved.

Wilson H.F.,Yale University | Wilson H.F.,Agriculture and Agri Food Canada | Saiers J.E.,Yale University | Raymond P.A.,Yale University | Sobczak W.V.,College of the Holy Cross, Worcester
Ecosystems | Year: 2013

We present the results of a full year of high-resolution monitoring of hydrologic event-driven export of stream dissolved organic matter (DOM) from the forested Bigelow Brook watershed in Harvard Forest, Massachusetts, USA. A combination of in situ fluorescent dissolved organic matter (FDOM) measurement, grab samples, and bioassays was utilized. FDOM was identified as a strong indicator of concentration for dissolved organic carbon (DOC, r 2 = 0.96), dissolved organic nitrogen (DON, r 2 = 0.81), and bioavailable DOC (BDOC, r 2 = 0.81). Relationships between FDOM and concentration were utilized to improve characterization of patterns of hydrological event-driven export and the quantification of annual export. This characterization was possible because DOM composition remained relatively consistent seasonally; however, a subtle shift to increased fluorescence per unit absorbance was observed for summer and fall seasons and percent BDOC did increase slightly with increasing concentrations. The majority of export occurred during pulsed hydrological events, so the greatest impact of bioavailable exports may be on downstream aquatic ecosystems. Export from individual events was highly seasonal in nature with the highest flow weighted mean concentrations (DOCFW) being observed in late summer and fall months, but the highest total export being observed for larger winter storms. Seasonal trends in DOC export coincide with weather driven changes in surface and subsurface flow paths, potential for depletion and rebuilding of a flushable soil organic matter pool, and the availability of terrestrial carbon sources such as leaf litter. Our approach and findings demonstrate the utility of high frequency FDOM measurement to improve estimates of intra-annual temporal trends of DOM export. © 2013 Springer Science+Business Media New York.

Chai L.-K.,Agriculture and Agri Food Canada | Wong M.-H.,Agriculture and Agri Food Canada | Mohd-Tahir N.,University of Malaysia, Terengganu | Hansen H.C.B.,Copenhagen University
Chemosphere | Year: 2010

Acephate is poorly sorbed to soil, thus the risk of leaching to the aquatic environment is high if it is not quickly degraded. The effect of soil moisture, temperature, microbial activity and application rate on acephate degradation has been studied in three Malaysian soils to examine and identify critical variables determining its degradation and mineralization kinetics. First-order kinetics could be used to describe degradation in all cases (r2 > 0.91). Acephate degraded faster in air-dry (t1/2 9-11 d) and field capacity (t1/2 10-16 d) soils than in the wet soils (t1/2 32-77 d). The activation energy of degradation was in the range 17-28 kJ mol-1 and significantly higher for the soil with higher pH and lower clay and iron oxide contents. Soil sterilization caused a 3- to 10-fold decrease in degradation rates compared to non-sterile soils (t1/2 53-116 d) demonstrating that acephate degradation is mainly governed by microbial processes. At 5-fold increase in application rates (25 μg g-1), half-life increased slightly (t1/2 13-19 d) or was unaffected. Half-life from acephate mineralization was similar to those from degradation but much longer at the 5-fold increase in acephate application rates (t1/2 41-96 d) demonstrating that degradation of metabolites is rate limiting. Thus, application of acephate should be restricted or avoided during wet seasons with heavy rainfall and flooded soil as in paddy cultivation. Sandy soils with low microbial activity are more prone to acephate leaching than clayey soils rich in humic matter. © 2010 Elsevier Ltd. All rights reserved.

Scott I.M.,Agriculture and Agri Food Canada | Thaler J.S.,Cornell University | Scott J.G.,Cornell University
Journal of Chemical Ecology | Year: 2010

The up-regulation of plant defense-related toxins or metabolic enzyme binding proteins often leads to a negative effect on herbivorous insects. These negative effects can manifest themselves at three points: changes in food ingestion, post-ingestive-changes, and post-digestive changes. Many studies have related the decrease in herbivore growth and/or survival with expression of chemicals that interfere with post-digestive effects such as the anti-nutritive effects of protease inhibitors. Nevertheless, it is unclear whether such compounds impact herbivores via earlier ingestive processes. We addressed this question by using a jasmonate-deficient mutant (Def-1), a jasmonate-overexpressor mutant (Prosystemin or Prosys), and wild-type tomato in three trials with 5th instar Trichoplusia ni. Decreases in relative growth rate (RGR) confirmed that T. ni fed on the Prosys plants developed poorly compared to those feeding on Def-1 plants (larvae on wild-types were intermediate). Preingestive and postingestive processes contributed to this effect. Total food ingested and the consumptive index were 25% lower on Prosys plants compared to Def-1 plants. Post-ingestive processes, measured by approximate digestibility, were 62% greater on Prosy plants. Post-digestive efficiency measured by conversion of ingested and digested food (ECI and ECD) decreased on Prosys plants two-fold compared to Def-1 plants. This post-digestive interference correlated well with the 2-fold decrease in activity of digestive enzymes, serine proteases, in Prosys-fed T. ni compared to those on Def-1 plants. No difference in detoxifying enzyme activity was detected. © 2010 Her Majesty the Queen in Right of Canada.

Liu D.,South China Agricultural University | Liu D.,Louisiana State University | Zhong T.,South China Agricultural University | Chang P.R.,Agriculture and Agri Food Canada | And 2 more authors.
Bioresource Technology | Year: 2010

Using a method of combined HNO3-KClO3 treatment and sulfuric acid hydrolysis, bamboo cellulose crystals (BCCs) were prepared and used to reinforce glycerol plasticized starch. The structure and morphology of BCCs were investigated using X-ray diffraction, electron microscopy, and solid-state 13C NMR. Results showed that BCCs were of typical cellulose I structure, and the morphology was dependent on its concentration in the suspension. BCC of 50-100 nm were assembled into leaf nervations at low concentration (i.e. 0.1 wt.% of solids), but congregated into a micro-sized "flower" geometry at high concentration (i.e. 10.0 wt.% of solids). Tensile strength and Young's modulus of the starch/BCC composite films (SBC) were enhanced by the incorporation of the crystals due to reinforcement of BCCs and reduction of water uptake. BCCs at the optimal 8% loading level exhibited a higher reinforcing efficiency for plasticized starch plastic than any other loading level. Crown Copyright © 2009.

Debevec A.H.,320 Morrill Hall | Cardinal S.,Agriculture and Agri Food Canada | Danforth B.N.,Cornell University
Zoologica Scripta | Year: 2012

The hymenopteran superfamily Apoidea includes the bees (Anthophila) as well as four predatory wasp families (Heterogynaidae, Ampulicidae, Sphecidae and Crabronidae) collectively referred to as the "sphecoid" or "apoid" wasps. The most widely cited studies suggest that bees are sister to the wasp family Crabronidae, but alternative hypotheses have been proposed based on both morphological and molecular data. We combined DNA sequence data from previously published studies and newly generated data for four nuclear genes (28S, long-wavelength rhodopsin, elongation factor-1α and wingless) to identify the likely sister group to the bees. Analysis of our four-gene data set by maximum likelihood and Bayesian methods indicates that bees most likely arise from within a paraphyletic Crabronidae. Possible sister groups to the bees include Philanthinae, Pemphredoninae or Philanthinae+Pemphredoninae. We used Bayesian methods to explore the robustness of our results. Bayes Factor tests strongly rejected the hypotheses of crabronid monophyly as well as placement of Heterogynaidae within Crabronidae. Our results were also stable to alternative rootings of the bees. These findings provide additional support for the hypothesis that bees arise from within Crabronidae, rather than being sister to Crabronidae, thus altering our understanding of bee ancestry and evolutionary history. © 2012 The Authors. Zoologica Scripta © 2012 The Norwegian Academy of Science and Letters.

Mesterhazy A.,Cereal Research Non profit Company | Lemmens M.,University of Natural Resources and Life Sciences, Vienna | Reid .L.M.,Agriculture and Agri Food Canada
Plant Breeding | Year: 2012

Ear rots caused by different Fusarium spp. are one of the most dangerous food and feed safety challenges in maize production. At present, the majority of the inbreds and hybrids are susceptible. Gibberella and Fusarium ear rots (caused by Fusarium graminearum and Fusarium verticillioides, respectively) are the two main diseases, but more than 10 further Fusarium spp. cause ear rots. Natural infection is initiated by a mixture of the local Fusarium spp., but usually one species predominates. Many maize breeders rely on natural infection to create sufficient levels of disease severity for selection-resistant genotypes; however, there are few locations where the natural infection is sufficiently uniform to make this selection efficient and successful. Thus, an artificial inoculation method normally performed with one fungal species is now used by more breeders. Most published papers on breeding for ear rot resistance are focused on either F. graminearum or F. verticillioides, and reports involving both or more Fusarium spp. are rare. Several reports support the hypothesis that resistance to multiple species especially F. graminearum, F. culmorum and F. verticillioides may be common. Significant differences in genotypic resistance after inoculation exist. Resistance to the two major modes of fungal entry into the ear, via the silk or through kernel wounds, is not correlated in all genotypes. The reason is not clear. When silk channel resistance was assessed, the data from natural and artificial inoculation trials correlated well. Analogous data relating to kernel resistance have not been published. Both native and exotic sources of resistance are important, but surprisingly little information is available. Few papers report on the use of artificial inoculation during inbred development. Most of the publications on inoculation are concerned with testing at later stages when combining ability is tested. Inbreds differ in general and specific combining ability for ear rot resistance. The expression of resistance to disease severity and resistance to toxins is often used as synonyms, but in fact they are not. Higher resistance to visual disease severities mostly results in lower toxin contamination, and the resistance level seems to be the most important factor regulating the toxin content. The mode of inheritance of resistance appears to differ: additive, possibly non-additive effects, digenic (dominant) and polygenic patterns have been identified. Improved phenotyping methods that take into account the influence of stalk rot and the use of several independent isolates are available. The QTLs mostly exhibit small effects and some are validated; however, marker-assisted selection in breeding cannot yet be foreseen. As the severity of natural infections tends to correlate with the artificial inoculation results, the incorporation of artificial inoculation methods in breeding programmes is now the most important task. As genotypic resistance differences between hybrids are high, the registration of hybrids should consider the use of the inoculation tests to choose most resistant hybrids for commercial production. This is the most rapid way to increase feed safety. © 2011 Blackwell Verlag GmbH.

Yemis O.,Agriculture and Agri Food Canada | Yemis O.,Pamukkale University | Mazza G.,Agriculture and Agri Food Canada
Bioresource Technology | Year: 2011

Furfural is a biomass derived-chemical that can be used to replace petrochemicals. In this study, the acid-catalyzed conversion of xylose and xylan to furfural by microwave-assisted reaction was investigated at selected ranges of temperature (140-190°C), time (1-30. min), substrate concentration (1:5-1:200 solid:liquid ratio), and pH (2-0.13). We found that a temperature of 180°C, a solid:liquid ratio of 1:200, a residence time of 20. min, and a pH of 1.12 gave the best furfural yields. The effect of different Brønsted acids on the conversion efficiency of xylose and xylan was also evaluated, with hydrochloric acid being found to be the most effective catalyst. The microwave-assisted process provides highly efficient conversion: furfural yields obtained from wheat straw, triticale straw, and flax shives were 48.4%, 45.7%, and 72.1%, respectively. © 2011.

Lonsdale O.,Plant Pest Diagnostics Center | Lonsdale O.,Agriculture and Agri Food Canada
Zootaxa | Year: 2011

The Californian species of Liriomyza Mik are revised, including descriptions, illustrations, photographs and a key to species. Sixty-three species are now known to occur in the state, 12 of which are described here as new: L. bispinula, L. conclavis, L. cunicularia, L. merga, L. miserabilis, L. nebulosa, L. parabella, L. phyllodes, L. projecta, L. salpingion, L. tricornis and L. trixivora. Liriomyza virginica Spencer is included as a junior synonym of L. helianthi Spencer, and L. similis Spencer is included as a synonym of L. artemisiae Spencer. Two species are newly recorded in the United States: L. equiseti Meijere, previously known from Canada and Europe, and L. montana Sehgal, previously known from Canada. A number of specimens of L. brassicae (Riley) have been identified as potential new host "races" or species. Morphological characters are provided to diagnose the sister species L. huidobrensis (Blanchard) and L. langei Frick, previously recognizable only on the basis of molecular data. Numerous new state, county and host records are also presented, and hosts are compared for five of the most common North American agricultural pests: L. brassicae, L. huidobrensis, L. langei, L. sativae Blanchard and L. trifolii (Burgess). California contains the highest diversity of Liriomyza known to occur in North America, containing approximately 70% of all described species known from the lower 48 states. Copyright © 2011. Magnolia Press.

Mumladze L.,Ilia State University | Murvanidze M.,Biocontrol | Behan-Pelletier V.,Agriculture and Agri Food Canada
Pedobiologia | Year: 2013

Soil inhabiting oribatid mites (Acari: Oribatida) are one of the most interesting groups of animals because of their ecological characteristics at the community level. However, existing knowledge does not provide comprehensive explanations of the mechanisms underlying their community or metacommunity structure. The aim of this study is to investigate peat bog inhabiting oribatid mite metacommunity distribution throughout the Holarctic region. Species incidence data was collected (mainly from published sources) for 46 peat bog localities, comprising a total of 410 species. Characteristics of species composition (coherence, turnover and boundary clumping) were analyzed to reveal patterns of peat bog oribatid metacommunity for different ecological guilds. We also applied correlation and regression analysis to detect whether peat bog oribatid communities show latitudinal gradient and distance decay in compositional similarity. Analysis of metacommunity structure showed non-random structure for all ecological guilds studied with dominating nested and Clementsian patterns. No significant evidence was found for latitudinal gradients in species composition whereas non-linear distance decay in compositional similarity is a common phenomenon for peat bog oribatid communities. We discuss these metacommunity patterns within the framework of existing hypotheses and conclude that the community level structure for peat bog oribatid species is largely determined by interspecific interactions and common biogeographical history, whereas metacommunity patterns are the result of postglacial colonization processes. © 2012 Elsevier GmbH.

Lester G.E.,U.S. Department of Agriculture | Makus D.J.,U.S. Department of Agriculture | Hodges D.M.,Agriculture and Agri Food Canada | Jifon J.L.,Texas AgriLife Research Center
Journal of Agricultural and Food Chemistry | Year: 2013

Comparison of spinach (Spinacia oleracea L.) cultivars Lazio and Samish grown during the summer solstice in the subarctic versus the winter solstice in the subtropics provided insight into interactions between production environment (light intensity), cultivar, and leaf age/maturity/position affecting bionutrient concentrations of vitamins (C, E, folate, K1, provitamin A), lutein, phenolics, and antioxidants. Growing spinach during the winter solstice in the subtropics resulted in increased leaf dry matter %, oxidized (dehydro) ascorbic acid (AsA), α- and γ-tocopherol, and total phenols but lower reduced (free) AsA, α-carotene, folate, and antioxidant capacity compared to summer solstice-grown spinach in the subarctic. Both cultivars had similar bionutrients, except for higher dehydroAsA, and lower α- and γ-tocopherol in 'Samish' compared to 'Lazio'. For most bionutrients measured, there was a linear, and sometimes quadratic, increase in concentrations from bottom to top canopy leaves. However, total phenolics and antioxidant capacity increased basipetally. The current study has thus demonstrated that dehydroAsA, α-tocopherol, and γ-tocopherol were substantially lower in subarctic compared to subtropical-grown spinach, whereas the opposite relationship was found for antioxidant capacity, α-carotene, and folates (vitamin B9). The observations are consistent with previously reported isolated effects of growth environment on bionutrient status of crops. The current results clearly highlight the effect of production environment (predominantly radiation capture), interacting with genetics and plant phenology to alter the bionutrient status of crops. While reflecting the effects of changing growing conditions, these results also indicate potential alterations in the nutritive value of foods with anticipated shifts in global climatic conditions. © 2013 American Chemical Society.

Hwang S.-F.,Crop Diversification Center North | Strelkov S.E.,University of Alberta | Feng J.,Crop Diversification Center North | Gossen B.D.,Agriculture and Agri Food Canada | Howard R.J.,Crop Diversification Center South
Molecular Plant Pathology | Year: 2012

Plasmodiophora brassicae causes clubroot disease in cruciferous plants, and is an emerging threat to Canadian canola (Brassica napus) production. This review focuses on recent studies into the pathogenic diversity of P. brassicae populations, mechanisms of pathogenesis and resistance, and the development of diagnostic tests for pathogen detection and quantification. Taxonomy: Plasmodiophora brassicae is a soil-borne, obligate parasite within the class Phytomyxea (plasmodiophorids) of the protist supergroup Rhizaria. Disease symptoms: Clubroot development is characterized by the formation of club-shaped galls on the roots of affected plants. Above-ground symptoms include wilting, stunting, yellowing and premature senescence. Disease cycle: Plasmodiophora brassicae first infects the root hairs, producing motile zoospores that invade the cortical tissue. Secondary plasmodia form within the root cortex and, by triggering the expression of genes involved in the production of auxins, cytokinins and other plant growth regulators, divert a substantial proportion of plant resources into hypertrophic growth of the root tissues, resulting in the formation of galls. The secondary plasmodia are cleaved into millions of resting spores and the root galls quickly disintegrate, releasing long-lived resting spores into the soil. A serine protease, PRO1, has been shown to trigger resting spore germination. Physiological specialization: Physiological specialization occurs in populations of P. brassicae, and various host differential sets, consisting of different collections of Brassica genotypes, are used to distinguish among pathotypes of the parasite. Detection and quantification: As P. brassicae cannot be cultured, bioassays with bait plants were traditionally used to detect the pathogen in the soil. More recent innovations for the detection and quantification of P. brassicae include the use of antibodies, quantitative polymerase chain reaction (qPCR) and qPCR in conjunction with signature fatty acid analysis, all of which are more sensitive than bioassays. Resistance in canola: Clubroot-resistant canola hybrids, recently introduced into the Canadian market, represent an important new tool for clubroot management in this crop. Genetic resistance must be carefully managed, however, as it has been quickly overcome in other regions. At least three resistance genes and one or two quantitative trait loci are involved in conferring resistance to P. brassicae. Root hair infection still occurs in resistant cultivars, but secondary plasmodia often remain immature and unable to produce resting spores. Fewer cell wall breakages occur in resistant hosts, and spread of the plasmodium through cortical tissue is restricted. More information on the genetics of clubroot resistance in canola is needed to ensure more effective resistance stewardship. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.

Lartillot N.,University of Montréal | Lartillot N.,CNRS Montpellier Laboratory of Informatics, Robotics and Microelectronics | Rodrigue N.,Agriculture and Agri Food Canada | Rodrigue N.,University of Ottawa | And 2 more authors.
Systematic Biology | Year: 2013

Modeling across site variation of the substitution process is increasingly recognized as important for obtaining more accurate phylogenetic reconstructions. Both finite and infinite mixture models have been proposed and have been shown to significantly improve on classical single-matrix models. Compared with their finite counterparts, infinite mixtures have a greater expressivity.However, they are computationally more challenging. This has resulted in practical compromises in the design of infinite mixture models. In particular, a fast but simplified version of a Dirichlet process model over equilibrium frequency profiles implemented in PhyloBayes has often been used in recent phylogenomics studies, while more refined model structures, more realistic and empirically more fit, have been practically out of reach. We introduce a message passing interface version ofPhyloBayes,implementing the Dirichletprocess mixture models aswell as more classical empirical matrices and finite mixtures. The parallelization is made efficient thanks to the combination of two algorithmic strategies: a partial Gibbs sampling update of the tree topology and the use of a truncated stick-breaking representation for the Dirichlet process prior. The implementation shows close to linear gains in computational speed for up to 64 cores, thus allowing faster phylogenetic reconstruction under complex mixture models. PhyloBayes MPI is freely available from our website [Bayesian inference; Dirichlet process; mixture models; phylogenetics; phylogenomics.] © The Author(s) 2013.

Sun Y.,Yuncheng University | Cui S.W.,Agriculture and Agri Food Canada | Gu X.,Jiangnan University | Zhang J.,Yuncheng University
Carbohydrate Polymers | Year: 2011

Water unextractable polysaccharide from bran of a Chinese black-grained wheat variety was isolated with saturated barium hydroxide as extraction medium. The fraction composed mainly of arabinose (36.53%) and xylose (61.31%), indicating the presence of pure arabinoxylans. The arabinoxylan isolates exhibited the high average molecular weight (Mw) of 3.81 × 105 and an intermediate Ara/Xyl (A/X) ratio of 0.60. The fraction consisted of a β-d-(1→4)-linked xylan backbone, which was mono- or disubstituted with α-l-arabinofuranosyl (Araf) groups at position O-3, O-2 or at both O-2 and O-3 positions. The xylan backbone contained a relatively high amount of unsubstituted xylopyranosyl (Xylp) residues (57.71%) and low amount of disubstituted Xylp residues (6.22%). About 22.0% of Xylp residues were monosubstituted at O-3 position. α-l-Araf side groups were prevalently (1→3)-linked to β-d-Xylp residues as single units. Moreover, small quantities of 2-, and 5-linked α-l-Araf indicated the presence of short arabinan side chains. © 2011 Elsevier Ltd. All rights reserved.

de Clercq P.,Ghent University | Mason P.G.,Agriculture and Agri Food Canada | Babendreier D.,CABI Europe Switzerland
BioControl | Year: 2011

The use of exotic (=alien) arthropods in classical and augmentative biological control programs has yielded huge economic and ecological benefits. Exotic species of arthropods have contributed to the suppression of key pests in agriculture and forestry or have aided in restoring natural systems affected by adventive species. However, adverse non-target effects of exotic biological control agents have been observed in a number of projects. Non-target effects range from very small effects, e. g. 2% parasitization on a non-target insect on a local level, to massive effects on a large scale. Until now, no consensus on how to judge the magnitude of non-target effects and whether these effects can be tolerated or are unacceptable has emerged. In this paper, we briefly review both the benefits of biological control as well as the associated risks including to human and animal health, plant health and particularly the environment. We also make an attempt at identifying the major challenges for assessing risks and for balancing benefits and risks. There is general agreement that sound risk assessment procedures should precede the release of exotic invertebrate biological control agents and a recent shift-especially for arthropod biological control-from introductions done without meaningful risk assessment studies to projects conducting thorough host range testing can be observed. However, overly stringent regulations that would preclude promising agents from being developed must be avoided. © 2011 International Organization for Biological Control (IOBC).

Wright S.G.,Queensland Museum | Skevington J.H.,Agriculture and Agri Food Canada
Zootaxa | Year: 2013

Three species of Episyrphus (Episyrphus) Matsumura, 1917 are here recorded in Australia: E. (E.) viridaureus (Wiedemann, 1824) and two new species E. (E.) oliviae Wright sp. nov. and E. (E.) glaber Wright sp. nov. A key to Australian Episyrphus (Episyrphus) species is provided, important taxonomic characters are illustrated and distributions of the three species are mapped. The distribution of E. (E.) viridaureus is extended to include Australia. Mitochondrial cytochrome c oxidase subunit I (COI) data are provided from some Episyrphus species to test morphological species concepts.

De Jong E.,Avantium Chemicals | Higson A.,NNFCC | Walsh P.,CiSET | Wellisch M.,Agriculture and Agri Food Canada
Biofuels, Bioproducts and Biorefining | Year: 2012

Around the world, significant able steps are being taken to move from today's fossil-based economy to a more sustainable economy based on biomass. A key factor in the realization of a successful bio-based economy will be the development of biorefinery systems allowing highly efficient and cost-effective processing of biological feedstocks to a range of bio-based products, and successful integration into existing infrastructure. The recent climb in oil prices and consumer demand for environmentally friendly products has now opened new windows of opportunity for bio-based chemicals and polymers. Industry is increasingly viewing chemical and polymer production from renewable resources as an attractive area for investment. Within the bio-based economy and the operation of a biorefinery, there are significant opportunities for the development of bio-based building blocks (chemicals and polymers) and materials (fiber products, starch derivatives, etc.). In many cases this happens in conjunction with the production of bioenergy or biofuels. The production of bio-based products could generate US$10-15 billion ofrevenue for the global chemical industry. The economic production of biofuels is often a challenge. The co--production of chemicals, materials food and feed can generate the necessary added value. This paper highlights all bio-based chemicals with immediate potential as biorefinery 'value added products'. The selected products are either demonstrating strong market growth or have significant industry investment in development and demonstration programs. The full IEA Bioenergy Task 42 report is available from © 2012 Her Majesty the Queen in Right of Canada.

Khakbazan M.,Agriculture and Agri Food Canada | Hamilton C.,Deerwood Soil and Water Management Association
Soil and Tillage Research | Year: 2012

The costs, risk, and additional management associated with the conversion of agricultural land from conventional tillage to conservation tillage play a significant role in the producers' likelihood of adoption of such practices. A local watershed organization in the South Tobacco Creek (STC) watershed in southern Manitoba has been collecting land management data for almost 20 years. As part of the national Watershed Evaluation of Beneficial Management Practices (WEBs), a tillage index and model were developed based on field tillage operations and production costs, and net incomes. The index and model quantified economic impacts of land management practices for three crop rotations under three tillage systems at the watershed scale. Based on a tillage index to define tillage levels for zero, minimum, and conventional tillage, a tillage cost function related tillage cost to tillage passes and crop residue management. Net income of crops and typical rotations under three tillage systems has been estimated. For canola, the greatest net income was generated in the conventional tillage (CT) system, which is attributed to the yield response to the tilled seedbed. As tillage frequency decreased, net income for canola declined. In contrast, the income response for cereals, such as wheat, was highest under minimum tillage (MT) due to reduced fuel and depreciation costs relative to conventional tillage. However net income for cereals managed with zero tillage (ZT) was significantly reduced due to increased equipment costs. Using the same tillage index, the model has produced results suggesting that for a wheat-canola rotation there is a significant difference between cropping system costs in areas of labour, oil and fuel, chemical and tillage costs; however, there is no significant difference between the three tillage levels in areas of total costs and net income. Although MT overall performed better compared to ZT or CT, net income of these three different tillage systems was offset between crops of the wheat-canola rotation and generally no statistically significant differences were observed. These results explained why most farmers in the STC watershed prefer conventional or minimum tillage to zero tillage-due to increased machinery investment and lower net returns for zero tillage. If conservation tillage is to be promoted in this region of Manitoba, additional incentives may be required to encourage its further adoption. However, increased net income for conservation tillage of cereals provides a clear incentive to adopt this practice. © 2011.

Li Y.,Rutgers University | Harris L.,Agriculture and Agri Food Canada | Dooner H.K.,Rutgers University
Plant Cell | Year: 2013

Mutator (Mu) elements, one of the most diverse superfamilies of DNA transposons, are found in all eukaryotic kingdoms, but are particularly numerous in plants. Most of the present knowledge on the transposition behavior of this superfamily comes from studies of the maize (Zea mays) Mu elements, whose transposition is mediated by the autonomous Mutator-Don Robertson (MuDR) element. Here, we describe the maize element TED (for Transposon Ellen Dempsey), an autonomous cousin that differs significantly from MuDR. Element excision and reinsertion appear to require both proteins encoded by MuDR, but only the single protein encoded by TED. Germinal excisions, rare with MuDR, are common with TED, but arise in one of the mitotic divisions of the gametophyte, rather than at meiosis. Instead, transposition-deficient elements arise at meiosis, suggesting that the double-strand breaks produced by element excision are repaired differently in mitosis and meiosis. Unlike MuDR, TED is a very low-copy transposon whose number and activity do not undergo dramatic changes upon inbreeding or outcrossing. Like MuDR, TED transposesmostly to unlinked sites and can form circular transposition products. Sequences closer to TED than to MuDR were detected only in the grasses, suggesting a rather recent evolutionary split from a common ancestor. © 2013 American Society of Plant Biologists. All rights reserved.

Kehlmaier C.,C o Senckenberg Natural History Collections Dresden | Dierick M.,Ghent University | Skevington J.H.,Agriculture and Agri Food Canada
Arthropod Systematics and Phylogeny | Year: 2014

The study is based on two Baltic amber inclusions from the middle Eocene, studied by means of micro-computed tomography (micro-CT). Inner male genitalic features are partly visualised and the specimens described as Metanephrocerus groehni Kehlmaier & Skevington sp.n. and Metanephrocerus hoffeinsorum Kehlmaier & Skevington sp.n. Based on a phenetic comparison of the basic morphological composition of male terminalia on a subfamily level, Metanephrocerus Aczél, 1948 and Protonephrocerus Collin, 1931 are excluded from Nephrocerinae and placed into the new subfamily Protonephrocerinae Aczél, 1948 stat.n. An identification key to the named morphospecies of Metanephrocerus is provided. © Senckenberg Gesellschaft für Naturforschung, 2014.

Kuhry P.,University of Stockholm | Dorrepaal E.,Umeå University | Hugelius G.,University of Stockholm | Schuur E.A.G.,University of Florida | Tarnocai C.,Agriculture and Agri Food Canada
Permafrost and Periglacial Processes | Year: 2010

Research on permafrost carbon has dramatically increased in the past few years. A new estimate of 1672 Pg C of belowground organic carbon in the northern circumpolar permafrost region more than doubles the previous value and highlights the potential role of permafrost carbon in the Earth System. Uncertainties in this new estimate remain due to relatively few available pedon data for certain geographic sectors and the deeper cryoturbated soil horizons, and the large polygon size in the soil maps used for upscaling. The large permafrost carbon pool is not equally distributed across the landscape: peat deposits, cryoturbated soils and the loess-like deposits of the yedoma complex contain disproportionately large amounts of soil organic matter, often exhibiting a low degree of decomposition. Recent findings in Alaska and northern Sweden provide strong evidence that the deeper soil carbon in permafrost terrain is starting to be released, supporting previous reports from Siberia. The permafrost carbon pool is not yet fully integrated in climate and ecosystem models and an important objective should be to define typical pedons appropriate for model setups. The thawing permafrost carbon feedback needs to be included in model projections of future climate change. © 2010 John Wiley & Sons, Ltd.

Todd-Brown K.E.O.,University of California at Irvine | Randerson J.T.,University of California at Irvine | Post W.M.,Oak Ridge National Laboratory | Hoffman F.M.,University of California at Irvine | And 4 more authors.
Biogeosciences | Year: 2013

Stocks of soil organic carbon represent a large component of the carbon cycle that may participate in climate change feedbacks, particularly on decadal and centennial timescales. For Earth system models (ESMs), the ability to accurately represent the global distribution of existing soil carbon stocks is a prerequisite for accurately predicting future carbon-climate feedbacks. We compared soil carbon simulations from 11 model centers to empirical data from the Harmonized World Soil Database (HWSD) and the Northern Circumpolar Soil Carbon Database (NCSCD). Model estimates of global soil carbon stocks ranged from 510 to 3040 Pg C, compared to an estimate of 1260 Pg C (with a 95 % confidence interval of 890-1660 Pg C) from the HWSD. Model simulations for the high northern latitudes fell between 60 and 820 Pg C, compared to 500 Pg C (with a 95% confidence interval of 380-620Pg C) for the NCSCD and 290 Pg C for the HWSD. Global soil carbon varied 5.9 fold across models in response to a 2.6-fold variation in global net primary productivity (NPP) and a 3.6-fold variation in global soil carbon turnover times. Model-data agreement was moderate at the biome level (R2 values ranged from 0.38 to 0.97 with a mean of 0.75); however, the spatial distribution of soil carbon simulated by the ESMs at the 1° scale was not well correlated with the HWSD (Pearson correlation coefficients less than 0.4 and root mean square errors from 9.4 to 20.8 kg C m-2). In northern latitudes where the two data sets overlapped, agreement between the HWSD and the NCSCD was poor (Pearson correlation coefficient 0.33), indicating uncertainty in empirical estimates of soil carbon. We found that a reduced complexity model dependent on NPP and soil temperature explained much of the 1° spatial variation in soil carbon within most ESMs (R2 values between 0.62 and 0.93 for 9 of 11 model centers). However, the same reduced complexity model only explained 10% of the spatial variation in HWSD soil carbon when driven by observations of NPP and temperature, implying that other drivers or processes may be more important in explaining observed soil carbon distributions. The reduced complexity model also showed that differences in simulated soil carbon across ESMs were driven by differences in simulated NPP and the parameterization of soil heterotrophic respiration (inter-model R2 = 0.93), not by structural differences between the models. Overall, our results suggest that despite fair global-scale agreement with observational data and moderate agreement at the biome scale, most ESMs cannot reproduce grid-scale variation in soil carbon and may be missing key processes. Future work should focus on improving the simulation of driving variables for soil carbon stocks and modifying model structures to include additional processes. © Author(s) 2013.

Aguiar A.P.,Federal University of Espirito Santo | Gibson G.A.P.,Agriculture and Agri Food Canada
Zootaxa | Year: 2010

A significant procedural problem in describing the leg surfaces of Hymenoptera, which has not been explicitly treated in the literature before, is identified and a mitigating solution is proposed. The first accurate, three-dimensional illustrations of the surfaces of the three pairs of legs are also provided to illustrate the problem and the proposed solution. In Hymenoptera, the orientation of the front, middle and hind pairs of legs relative to the body can and often do differ in direction by up to 180° between the front and hind legs. Furthermore, the tibiae and tarsi are usually held at an abrupt angle relative to the femora. Because of this, the terms anterior, posterior, lateral, outer, mesal, inner, dorsal, and ventral, when applied to surfaces of different parts of different legs will frequently refer to non-homologous areas depending on whether the terms are interpreted or used in an anatomic sense or based on the specific direction and orientation of the part of the leg being described (vernacular sense). Authors often use the vernacular interpretation, but we show that such usage makes the terminology on average 53.1% incompatible for the same anatomical surfaces of the femora, tibiae and tarsi of the three sets of legs. To create equivalence between anatomical and vernacular senses, four intuitive vernacular terms are proposed as explanatory or auxiliary terms for the anatomical terms "dorsal", "ventral" "anterior", and "posterior", respectively, kickface, gripface, foreface, and backface. The terms are proposed as auxiliary or explanatory terms and not as substitutes for the anatomical terms. Copyright © 2010 Magnolia Press.

Liu T.,Harbin Institute of Technology | Ma Y.,Harbin Institute of Technology | Xue S.,Agriculture and Agri Food Canada | Shi J.,Agriculture and Agri Food Canada
LWT - Food Science and Technology | Year: 2012

Maize starch powder was exposed to a 60Co source (0, 1, 2, 5, 10, 20, 50, 100, 200, or 500 kGy) and the effects of γ-irradiation treatment on the structure and physicochemical properties of the starch granules were studied. The results showed that peak, trough, final, and setback viscosities were significantly reduced, whereas the solubility was increased following irradiation. Gelatinization temperature and enthalpy decreased significantly when the dose is higher than 50 kGy. On the surface, the starch granules did not display any visible physical change up to a 500 kGy dose was. X-ray diffraction (XRD) analysis showed that the relative crystallinity of starch decreased slightly, and the starch exhibited an A-pattern without any change. Fourier transform infrared (FTIR) spectral intensity at 1018 cm -1 increased with the irradiation dose up to 200 kGy. Irradiation dose was positively correlated with solubility and negatively correlated with relative crystallinity. There were high positive correlations between thermal properties and pasting properties. © 2011.

Van der Heyden H.,Compagnie de recherche Phytodata Inc. | Carisse O.,Agriculture and Agri Food Canada | Brodeur L.,Compagnie de recherche Phytodata Inc.
Crop Protection | Year: 2012

Botrytis leaf blight (BLB) of onion is a well-documented disease and several management tools are available. However, achieving good control with minimum use of fungicides is time consuming and requires dedication on the part of growers. In this study, three indicators for the initiation of fungicide spray programs were compared. The study was conducted in 2008, 2009 and 2010 at commercial onion farms located in the muck soil area southwest of Montreal. The indicators evaluated were: 1) first airborne Botrytis squamosa conidia detected; 2) cumulative airborne conidium concentration (ACC) of 15conidiam -3; 3) first lesion caused by B. squamosa detected. The interval between subsequent fungicide applications was determined by taking into account sporulation potential, airborne conidium concentration and lesion density. Reliability of the indicators was evaluated on the basis of observed maximum disease level, area under the disease progress curve and rate of disease progress. Initiation of the fungicide spray program when the first airborne B. squamosa conidia were detected resulted in the lowest values for maximum disease level and area under the disease progress curve, followed by initiation when a cumulative concentration of 15conidiam -3 was reached, and by initiation when the first lesion was detected. However, there was no significant difference in rate of disease progress, calculated using data from fields where spray programs were initiated based on the different indicators. The critical disease level for curative fungicide applications (ten lesions per leaf) was not reached when the spray program was initiated upon detection of the first conidia; was reached a few days after bulb initiation for a spray program initiated at a cumulative ACC of 15conidiam -3; and was reached prior to bulb initiation for the spray program initiated when the first lesion was detected. These results suggest that to avoid yield reduction, BLB should be managed such that the disease does not reach the exponential phase. This was achieved by initiating the fungicide spray program based on first conidia detected. © 2011.

Yemis O.,Agriculture and Agri Food Canada | Yemis O.,Pamukkale University | Mazza G.,Agriculture and Agri Food Canada
Bioresource Technology | Year: 2012

Optimization of acid-catalyzed conversion conditions of wheat straw into furfural, 5-hydroxymethylfurfural (HMF), glucose, and xylose was studied by response surface methodology (RSM). A central composite design (CCD) was used to determine the effects of independent variables, including reaction temperature (140-200 °C), residence time (1-41. min), pH (0.1-2.1), and liquid:solid ratio (15-195. mL/g) on furan and sugar production. The surface response analysis revealed that temperature, time and pH had a strong influence on the furfural, HMF, xylose and glucose yield, whereas liquid to solid ratio was found not to be significant. The initial pH of solution was the most important variable in acid-catalyzed conversion of wheat straw to furans. The maximum predicted furfural, HMF, xylose and glucose yields were 66%, 3.4%, 100%, and 65%, respectively. This study demonstrated that the microwave-assisted process was a very effective method for the xylose production from wheat straw by diluted acid catalysis. © 2012.

Kowalenko C.G.,Agriculture and Agri Food Canada | Ihnat M.,2521 Blue Jay Drive
Canadian Journal of Soil Science | Year: 2010

The pH and Mehlich-3extractable concentrations of a variety of elements including those that were study treatments (Ca, Mn and Zn) and those that were expected to be influenced by the treatments (Mg, Sr, K, Rb, Na, Al, Fe, Si and Cu) were determined in soil samples from a cauliflower field trial conducted between 1979 and 1985. The treatments were limestone applied to the soil at three rates (0, 9 and 19 Mg ha-1) and Zn and Mn foliar applications. The pH of air-dried samples varied only slightly when analysed within each year of sampling versus as one batch after the trial was completed, which showed that the samples were stable over the long time the samples had to be stored through the field trial period and until the samples were analysed. Being able to do all the analyses in one batch also facilitated the application of quality control to ensure comparability of results. There were differences in the soil measurements of most of the elements taken pre-plant versus post-harvest, showing that the time of sampling must be consistent for experimental and soil test interpretations. Post-harvest samples (i.e., focusing on residual effects of limestone application) were selected to examine the treatment effects. Limestone application had wide-ranging and variable effects on extractable elements in the soil. Soil pH and extractable Ca increased with increased limestone rate as expected, while the amount of extractable Mn, Zn, K, Mg, Na, Al and Fe decreased. Extractable Sr, Si and Cu increased with limestone applications. Extractable Ca, Zn, Mg, Al and Si were affected to 15-30 cm depth, and pH and extractable Mn, Rb and Fe were affected to 30-60 cm. Subsurface (>15 cm depth) Sr, K, Na and Cu were not influenced by the limestone treatments. The effect of limestone on the elements tended to correspond to the effect previously observed on the contents of these elements in cauliflower plants. The ability of Mehlich-3extract solution to reflect the availability of elements to plants and the effect of limestone applications on other elements simultaneously showed the potential for this soil test solution to predict the need for nutrient amendments to prevent lime-induced deficiencies.

Liu M.,Agriculture and Agri Food Canada | Liu M.,Cereal Disease Laboratories | Hambleton S.,Agriculture and Agri Food Canada
Mycological Progress | Year: 2013

Intra-specific classification of Puccinia coronata has been controversial, with previous approaches falling into three major categories: 1. A two-species system, namely P. coronifera and P. coronata; 2. The same two-species system subdivided into many formae speciales, in which the host range of each is restricted to species within one genus of Poaceae; 3. A one-species system, P. coronata, subdivided into a few varieties with host ranges that may overlap. To re-assess these concepts in the context of multigene analyses and comparative morphological assessments, data were generated for a comprehensive set of herbarium and recently collected specimens, representing a broad range of hosts and geographic origins. Phylogenetic analyses of a combined data set of DNA sequences for four loci (BT, COI, ITS, and RPB2) revealed a high degree of genetic variation. Morphological differences among phylogenetic lineages were overlapping but nine lineages were differentiated using calculated means for teliospore and urediniospore length/width as well as measurements for the teliospore hilum and digitation. The taxon infecting Avena also comprises collections from a wide range of other grass hosts while other lineages, such as those on Bromus and Agrostis, were restricted in host association. Type specimen DNA sequences included in the analyses resolved the placement of five previously described varieties. Based on evidence of host specificity, morphology and multigene analyses, we recognized seven species, one of which was further divided into two varieties. Expanded descriptions, illustrations and a synoptic key are provided. A new series, Puccinia Series Coronata, was erected to accommodate all the lineages comprising P. coronata sensu lato. © 2012 The Author(s).

News Article | November 2, 2016

Including canola oil in a healthy diet may help reduce abdominal fat in as little as four weeks, according to health researchers. "Visceral, or abdominal, fat increases the risk for cardiovascular disease, and is also associated with increased risk for conditions such as metabolic syndrome and diabetes," said Penny M. Kris-Etherton, Distinguished Professor of Nutrition, Penn State. "Monounsaturated fats in canola oil decrease this fat that has adverse health effects." Kris-Etherton and colleagues found that after one month of adhering to diets that included canola oil, participants had .11 kilograms, or a quarter pound, less belly fat than they did before the diet. They also found that the weight lost from the mid-section did not redistribute elsewhere in the body. The researchers report their results at The Obesity Society's Annual Scientific Meeting today (Nov. 2). "As a general rule, you can't target weight loss to specific body regions," said Kris-Etherton. "But monounsaturated fatty acids seem to specifically target abdominal fat." In order to incorporate canola oil into the diet, Kris-Etherton suggests using it when sautéing foods, in baking, adding it to a smoothie and in salad dressings. Canola oil is high in monounsaturated fatty acids, which have been shown to have beneficial effects on body composition, especially in people with obesity. When participants consumed conventional canola oil or high-oleic acid canola oil for just four weeks, they lost abdominal fat. The researchers tested the effect of five different vegetable oil blends in 101 participants' diets through a controlled study. The subjects were randomly assigned to follow for four weeks each of the treatment oil diets: conventional canola, high-oleic acid canola, high-oleic acid canola with DHA (a type of omega-3 fatty acid), corn/safflower and flax/safflower. After each four-week diet period, participants were given a four-week break before starting the next diet period. The participants consumed two smoothies during the day, which contained the specified treatment oil. The quantity of oil was calculated based on the participant's energy needs. For example, a participant who was on a 3,000-calorie diet would receive 60 grams of the treatment oil per day, providing 18 percent of his or her total dietary energy. Each smoothie would then contain 100 grams of orange sherbet, 100 grams of non-fat milk, 100 grams of frozen unsweetened strawberries and 30 grams of canola oil. A hundred grams is equivalent to roughly three-and-a-half ounces and 30 grams is approximately two tablespoons. The canola oil was carefully incorporated into the test diets so as to not exceed the participants' daily calorie needs. All of the participants had abdominal obesity, or increased waist circumference, and were either at risk for or had metabolic syndrome -- a group of conditions including obesity, type 2 diabetes, high blood pressure, high blood sugar, low HDL (also known as good cholesterol) and excess body fat around the waist. The researchers point out that further studies should be conducted to look at the long-term effects of a diet high in monounsaturated fatty acids, like canola oil. Also contributing to this research were Xiaoran Liu, a doctoral student, Sheila G. West, professor, biobehavioral health and nutritional sciences, Jennifer A. Fleming, instructor and clinical research coordinator, nutritional sciences, and Cindy E. McCrea, graduate student, biobehavioral health, all at Penn State; Benoît Lamarche, professor, nutrition, and Patrick Couture, professor, endocrinology and nephrology, both at Laval University; David J. A. Jenkins, professor, nutritional sciences and medicine, University of Toronto; Shuaihua Pu, a doctoral student, and Peter J. H. Jones, Canada Research Chair in Functional Foods and Nutrition, both at University of Manitoba; and Philip W. Connelly, staff scientist, Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto. Agriculture and Agri Food Canada, the Canola Council of Canada, the Dow Agrosciences and Flax Council of Canada and the National Center for Advancing Translational Sciences all supported this research.

Schmidt P.J.,Public Health Agency of Canada | Pintar K.D.M.,Public Health Agency of Canada | Fazil A.M.,Public Health Agency of Canada | Topp E.,Agriculture and Agri Food Canada
Risk Analysis | Year: 2013

Dose-response models are the essential link between exposure assessment and computed risk values in quantitative microbial risk assessment, yet the uncertainty that is inherent to computed risks because the dose-response model parameters are estimated using limited epidemiological data is rarely quantified. Second-order risk characterization approaches incorporating uncertainty in dose-response model parameters can provide more complete information to decisionmakers by separating variability and uncertainty to quantify the uncertainty in computed risks. Therefore, the objective of this work is to develop procedures to sample from posterior distributions describing uncertainty in the parameters of exponential and beta-Poisson dose-response models using Bayes's theorem and Markov Chain Monte Carlo (in OpenBUGS). The theoretical origins of the beta-Poisson dose-response model are used to identify a decomposed version of the model that enables Bayesian analysis without the need to evaluate Kummer confluent hypergeometric functions. Herein, it is also established that the beta distribution in the beta-Poisson dose-response model cannot address variation among individual pathogens, criteria to validate use of the conventional approximation to the beta-Poisson model are proposed, and simple algorithms to evaluate actual beta-Poisson probabilities of infection are investigated. The developed MCMC procedures are applied to analysis of a case study data set, and it is demonstrated that an important region of the posterior distribution of the beta-Poisson dose-response model parameters is attributable to the absence of low-dose data. This region includes beta-Poisson models for which the conventional approximation is especially invalid and in which many beta distributions have an extreme shape with questionable plausibility. © 2013 Society for Risk Analysis.

Li H.,Nanchang University | Li H.,Agriculture and Agri Food Canada | Deng Z.,Nanchang University | Liu R.,Agriculture and Agri Food Canada | And 2 more authors.
Food Chemistry | Year: 2013

The carotenoid compositions, antioxidant activities and the potential cardio-protective role of 13 tomato cultivars with distinct colour were studied. Colour coordinates were evaluated by colorimeter and the carotenoid compositions were analysed by UPLC. Red tomatoes had the highest total carotenoid contents (TCC) and antioxidant activities, followed by purple, orange, pink and yellow ones. The TCC were 120.5-278.0 μg/g DW, and the antioxidant activities were 21.32-40.07 μmol TE/g DW (PCL), 64.42-89.98% (DPPH) and 10.47-13.76 μmol TE/g DW (ORAC), respectively. The lipophilic extracts were also found to prevent cell death in a cell-based model system using cardiac H9c2 cells and H2O2, via attenuation of the caspase-3 and matrix metalloproteinase-2 activities. The extracts of different tomatoes showed strong but different antioxidant activities. Roles of total and individual carotenoids in the antioxidant activities were studied and lycopene showed the highest correlation. Results of this study can be used to guide the development of new tomato cultivars and functional foods, and benefit the consumers. © 2012 Elsevier Ltd. All rights reserved.

Hannoufa A.,Agriculture and Agri Food Canada | Pillai B.V.S.,Dow AgroSciences | Chellamma S.,Dow AgroSciences
Transgenic Research | Year: 2014

The ultimate value of the Brassica napus (canola) seed is derived from the oil fraction, which has long been recognized for its premium dietary attributes, including its low level of saturated fatty acids, high content of monounsaturated fatty acids, and favorable omega-3 fatty acid profile. However, the protein (meal) portion of the seed has also received favorable attention for its essential amino acids, including abundance of sulfur-containing amino acids, such that B. napus protein is being contemplated for large scale use in livestock and fish feed formulations. Efforts to optimize the composition of B. napus oil and protein fractions are well documented; therefore, this article will review research concerned with optimizing secondary metabolites that affect the quality of seed oil and meal, from undesirable anti-nutritional factors to highl value beneficial products. The biological, agronomic, and economic values attributed to secondary metabolites have brought much needed attention to those in Brassica oilseeds and other crops. This review focuses on increasing levels of beneficial endogenous secondary metabolites (such as carotenoids, choline and tochopherols) and decreasing undesirable antinutritional factors (glucosinolates, sinapine and phytate). Molecular genetic approaches are given emphasis relative to classical breeding. © 2013 Her Majesty the Queen in Right of Canada.

Borucki Castro S.I.,Agriculture and Agri Food Canada | Berthiaume R.,Agriculture and Agri Food Canada | Robichaud A.,Food Directorate | Lacasse P.,Agriculture and Agri Food Canada
Journal of Dairy Science | Year: 2012

Two studies were conducted to determine the effects of dietary iodine and teat-dipping practices on iodine concentrations in milk. In the first study, 63 cows in mid lactation were assigned to a 3 × 3 factorial design in which the main effects were dietary iodine levels (0.3, 0.6, and 0.9. mg of dietary I/kg of dry matter) and 3 different postdip managements (chlorhexidine with dip cup, 1% iodine dip cup, and 1% iodine by manual spray). During the 13-d pre-experimental period and the 15-d experimental period, noniodized sanitizers were used in premilking management. During the pre-experimental period, the levels of milk iodine averaged 241.2 ± 5.8 μg/kg, and no relationship was found with lactation number, days in milk, or milk production. Milk iodine concentrations increased linearly with iodine intake. Although teat dipping with 1% iodine had no effect on milk iodine concentration, the same solution applied by spraying greatly increased milk iodine levels. The second study was conducted to determine the effects of udder preparation before milking on milk iodine concentrations. Thirty-two lactating cows were assigned to 4 treatments: no predip (Con); predip with a predip solution containing 0.5% iodine. +. complete cleaning (Comp); predip with a postdip solution containing 1% iodine. +. complete cleaning (Post); and predip with a predip solution containing 0.5% iodine. +. incomplete cleaning (Inc). During the 14-d pre-experimental period and the 19-d experimental period, cows were fed the same diet, and noniodized sanitizers were used for postmilking dipping. During the last week of treatment, milk iodine averaged 164, 189, 218, and 252 ± 9.8 μg/kg for Con, Comp, Post, and Inc, respectively. Preplanned orthogonal contrasts indicated that predipping with a 0.5% iodine predip solution completely wiped off (Comp) tended to increase milk iodine content above that of the control and that the iodine content of Post and Inc were higher than that of the Comp treatment. The results of the first experiment confirm that, to preserve milk safety, iodine should not be fed above requirements. Spraying iodine-based teat-dipping solutions results in large increases in milk iodine content and should be avoided. Predipping teats with an iodine-based sanitizer is an acceptable practice, but must be performed with the appropriate product and completely wiped off before milking. © 2012 American Dairy Science Association.

Xing X.,University of Guelph | Cui S.W.,Agriculture and Agri Food Canada | Nie S.,Nanchang University | Phillips G.O.,Glyndwr University | And 2 more authors.
Carbohydrate polymers | Year: 2015

Main objective of this study was to investigate the detailed structural information about O-acetylated sugar residues in Dendronan(®). A water solution (2%, w/w) of Dendronan(®) was treated with endo-β-mannanase to produce oligosaccharides rich in O-acetylated sugar residues. The oligosaccharides were partly recovered by ethanol precipitation (70%, w/w). The recovered sample (designated Hydrolyzed Dendrobium officinale Polysaccharide, HDOP) had a yield of 24.7% based on the dry weight of Dendronan(®) and was highly O-acetylated. A D2O solution of HDOP (6%, w/w) generated strong signals in (1)H, (13)C, 2D (1)H-(1)H COSY, 2D (1)H-(1)H TOCSY, 2D (1)H-(1)H NOESY, 2D (1)H-(13)C HMQC, and 2D (1)H-(13)C HMBC NMR spectra. Results of NMR analyses showed that the majority of O-acetylated mannoses were mono-substituted with acetyl groups at O-2 or O-3 position. There were small amounts of mannose residues with di-O-acetyl substitution at both O-2 and O-3 positions. Minor levels of mannoses with 6-O-acetyl, 2,6-di-O-acetyl, and 3,6-di-O-acetyl substitutions were also identified. Much information about sugar residue sequence was extracted from 2D (1)H-(13)C HMBC and 2D (1)H-(1)H NOESY spectra. (1)J(C-H) coupling constants of major sugar residues were obtained. Evidences for the existence of branches or O-acetylated glucoses in HDOP were not found. The major structure of Dendronan(®) is shown as follows: [Formula: see text] M: β-D-mannopyranose; G: β-D-glucopyranose; a: O-acetyl group. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Frey S.K.,Agriculture and Agri Food Canada | Rudolph D.L.,University of Waterloo | Lapen D.R.,Agriculture and Agri Food Canada | Ball Coelho B.R.,Ontario Ministry of Agriculture
Water Resources Research | Year: 2012

A scarcity of information exists on how physical processes govern the movement of liquid manure, or other viscous fluids, through layered macroporous soils. To elucidate these complex flow and transport phenomena, a viscosity dependent, two-dimensional dual-permeability model that considers macropore anisotropy is employed to simulate field experiments where liquid swine manure (LSM) was applied to silt loam with both a soil crust and plowpan layer present. Using data from the field experiment as a benchmark, the model was used to predict nutrient (NH 4-N and total P) breakthrough to tile drains; and to assess the influence of reduced permeability crust and plowpan layers, and fluid viscosity, on solute movement within 48 h of LSM application. Results demonstrate the importance of viscosity on flow and transport in macroporous soils. By increasing LSM viscosity, nutrient breakthrough to tile drains can be greatly reduced, and near surface nutrient retention can increase. The presence of a nonmacroporous soil crust layer can also lead to reduced nutrient concentrations in tile discharge by reducing pressure heads in the underlying A-horizon soil matrix, resulting in reduced macropore flow; whereas a low permeability plowpan layer at the base of the A horizon can increase pressure heads in the A-horizon soil matrix and lead to increased macropore flow. Multiple target point parameter sensitivity analysis revealed that relative parameter sensitivity can be a transient characteristic, and that hydraulic properties of the A and B horizon tend to exhibit their greatest influence over the respective early and late time solute breakthrough characteristics. Copyright 2012 by the American Geophysical Union.

Soliman S.S.M.,University of Guelph | Soliman S.S.M.,Zagazig University | Tsao R.,Agriculture and Agri Food Canada | Raizada M.N.,University of Guelph
Journal of Natural Products | Year: 2011

Taxus trees possess fungal endophytes reported to produce paclitaxel. Inhibitors that block early steps in plant paclitaxel biosynthesis were applied to a paclitaxel-producing fungus to determine whether these steps are shared. The plant paclitaxel backbone is reportedly derived from the non-mevalonate terpenoid pathway, while the side chain is phenylalanine-derived. Evidence that the shikimate pathway contributes to fungal paclitaxel was shown by decreased paclitaxel accumulation following inhibition of phenylalanine ammonia lyase. Expression of another shikimate pathway enzyme, 3-dehydroquinate synthase, coincided with paclitaxel production. The importance of the mevalonate pathway in fungal paclitaxel biosynthesis was shown by inhibition of fungal paclitaxel accumulation using compactin, a specific inhibitor of 3-hydroxy-3-methyl- glutaryl-CoA reductase. Expression of another mevalonate pathway enzyme, 3-hydroxy-3-methyl-glutaryl-CoA synthase, coincided with fungal paclitaxel accumulation. Unexpectedly, results from using fosmidomycin suggested that fungal paclitaxel requires 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), an enzyme in the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway normally found in bacteria/plants. Additional lines of evidence support this finding; first, a plant DXR antibody recognized a fungal peptide of the correct size; second, expression of an apparent fungal DXR ortholog correlated to changes in paclitaxel production; finally, BLAST searching identified a gene putatively encoding 1-deoxy-d-xylulose-5-phosphate synthase, the first enzyme in the MEP pathway in Aspergillus. © 2011 The American Chemical Society and American Society of Pharmacognosy.

Yang X.,University of Waterloo | Yang X.,Agriculture and Agri Food Canada | Ma K.,University of Waterloo
Journal of Bacteriology | Year: 2010

A thioredoxin reductase and a thioredoxin were purified to homogeneity from a cell extract of Thermotoga maritima. The thioredoxin reductase was a homodimeric flavin adenine dinucleotide (FAD)-containing protein with a subunit of 37 kDa estimated using SDS-PAGE, which was identified to be TM0869. The amino acid sequence of the enzyme showed high identities and similarities to those of typical bacterial thioredoxin reductases. Although the purified T. maritima thioredoxin reductase could not use thioredoxin from Spirulina as an electron acceptor, it used thioredoxin that was purified from T. maritima by monitoring the dithiothreitoldependent reduction of bovine insulin. This enzyme also catalyzed the reduction of benzyl viologen using NADH or NADPH as an electron donor with apparent Vmax values of 1,111 ± 35 μmol NADH oxidized min-1mg-1 and 115 ± 2.4 μmol NADPH oxidized min-1mg-1, respectively. The apparent K m values were determined to be 89 ± 1.1 μM, 73 ± 1.6 μM, and 780 ± 20 μM for benzyl viologen, NADH, and NADPH, respectively. Optimal pH values were determined to be 9.5 and 6.5 for NADH and NADPH, respectively. The enzyme activity increased along with the rise of temperature up to 95°C, and more than 60% of the activity remained after incubation for 28 h at 80°C. The purified T. maritima thioredoxin was a monomer with a molecular mass of 31 kDa estimated using SDS-PAGE and identified as TM0868, which exhibited both thioredoxin and thioltransferase activities. T. maritima thioredoxin and thioredoxin reductase together were able to reduce insulin or 5,5′-dithio-bis(2-nitrobenzoic acid) using NAD(P)H as an electron donor. This is the first thioredoxin-thioredoxin reductase system characterized from hyperthermophilic bacteria. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Frey S.K.,Agriculture and Agri Food Canada | Rudolph D.L.,University of Waterloo | Parkin G.W.,University of Guelph
Soil Science Society of America Journal | Year: 2012

This study investigated post-harvest temporal changes in macroporosity and hydraulic properties, relative to subsurface drain position, at three different locations within a single fi eld. Tension and double-ring infi ltrometer tests were conducted on the fi eld surface at distances between 0 and 4 m from drains to determine hydraulic conductivity and a soil structural parameter as a function of pressure head [K(ψ) and α′(ψ), respectively], and fi eld-saturated hydraulic conductivity (K fs). At two of the locations, duplicate sets of infi ltration tests were conducted on signifi cantly drier soils about 1 mo after the initial tests. Macroporosity values at each location were determined visually and with capillary theory (i.e., hydraulically effective macroporosity, ε m ), and results from the two methods were compared. At the two fi eld locations with relatively low B horizon permeability, surface soil K fs was greatest above the drains; however, at the location with the greatest B horizon permeability, surface soil K fs increased away from the drain. The K fs was also signifi cantly (P < 0.1) greater under drier soil conditions. Although α′(ψ) and K(ψ) relationships were not infl uenced by drain position, they did exhibit temporal variability. For ψ < -2 cm, both α′(ψ) and K(ψ) were less in dry soil, whereas for ψ > -1 cm, both α′(ψ) and K(ψ) tended to be greater in dry soil. The em was not infl uenced by drain position but tended to be greater in wetter soil, although em attributable to pores with equivalent diameter >0.3 cm tended to be greater in dry soil. The em was approximately 100 times less than visible macroporosity. © Soil Science Society of America.

Reuter T.,Agriculture Center | Alexander T.W.,University of Vermont | McAllister T.A.,Agriculture and Agri Food Canada
Applied and Environmental Microbiology | Year: 2011

Safe disposal of dead livestock and contaminated manure is essential for the effective control of infectious disease outbreaks. Composting has been shown to be an effective method of disposal, but no information exists on its ability to contain diseases caused by spore-forming bacteria, such as Bacillus anthracis. Duplicate composters (east and west), each containing 16 dead cattle, were constructed (final capacity, 85,000 kg). Spores (10 7 CFU/g manure) of Bacillus licheniformis and Bacillus thuringiensis were mixed with autoclaved feedlot manure and placed in either sterile vials or porous nylon bags. Compost temperatures in the west composter were slightly higher than in the east composter. Viable B. thuringiensis spores were reduced to ≤10 2 CFU in all samples after 112 days but were isolated from bags (west composter) at ≤10 2 and at 10 5 CFU (east composter) after 230 days. In contrast, B. licheniformis was at ≤10 2 CFU in vials (west composter) after 112 days but remained at 10 6 CFU after 230 days (east composter). Similarly, B. licheniformis in bags was not detected after 230 days in the west composter but remained at 10 7 CFU in the east composter. Our study suggests that spore viability was reduced in the west composter by exposure to compost and elevated temperatures over time. Different temperature profiles may explain why spores remained viable in the east structure but were largely rendered nonviable in the west structure. Under practical conditions, variation in composting microclimates may preclude the complete inactivation of Bacillus spores, including those of B. anthracis, during composting. However, composting may still have merit as a method of biocontainment, reducing and diluting the transfer of infectious spores into the environment. © 2011, American Society for Microbiology.

Stanford K.,Agriculture Center | Koohmaraie M.,Forest Laboratories | Gill C.O.,Agriculture and Agri Food Canada
Journal of Food Protection | Year: 2013

Due to the expense of monitoring multiple serotypes of Escherichia coli at slaughter, a study was conducted at a beef abattoir in southern Alberta to determine relationships between E. coli and E. coli O157:H7 on hides. Swab samples were collected from carcasses immediately prior to hide removal over 8 weeks in summer (n = 591) and winter (n = 686). Detection of E. coli was highest in summer (P , 0.05), although detection of E. coli O157:H7 did not differ by season. Numbers of E. coli did not vary by season, but were affected by slaughter plant hygiene schedules. E. coli O157:H7 was more likely (P , 0.001) to be detected on hides of carcasses with the most E. coli (.3.5 log CFU/50 cm2). For E. coli ,3.5 log CFU/50 cm2, the likelihood of detecting E. coli O157:H7 did not differ. Consequently, for 83% of carcasses, there was no relationship between numbers of E. coli and detection of E. coli O157:H7 on hides. Copyright ©, International Association for Food Protection.

Li H.,Nanchang University | Li H.,Agriculture and Agri Food Canada | Deng Z.,Nanchang University | Liu R.,Agriculture and Agri Food Canada | And 2 more authors.
Food Chemistry | Year: 2012

All-trans-lutein, lycopene, β-carotene and their 22 cis-isomers in 20 tomato breeding were separated and identified by a rapid and sensitive UPLC method using a 1.7 μm C 18 column and a new gradient mobile phase based on methanol-MTBE-water in 15 min. All-trans-carotenoids were predominant, but 9-cis, 13-cis-lutein, 5-cis, 9-cis, 13-cis, 15-cis, di-cis-lycopene, 9-cis, 13-cis, 15-cis and di-cis-β-carotene were also found. The cis-isomers were identified using absorption around 330 nm and the Q-ratio. The total antioxidant activities as evaluated by PCL and DPPH assays were found to correlate well with the total carotenoid content, but not with the individual carotenoid or its different isomers. This paper provides an efficient analytical method for obtaining a complete picture of carotenoids in tomatoes. It can be a valuable tool for plant breeders, food processors and researchers in developing designer tomatoes and tomato-products with unique carotenoid compositions, and functional properties. © 2011 Elsevier Ltd. All rights reserved.

Nie S.-P.,Nanchang University | Nie S.-P.,Agriculture and Agri Food Canada | Xie M.-Y.,Nanchang University
Food Hydrocolloids | Year: 2011

Tea polysaccharides were found to be mostly glycoconjugates in which a protein carries one or more carbohydrate chains covalently attached to a polypeptide backbone, usually via N- or O-linkages. It has been reported that they have showed various bioactivities, such as anti-cancer, anti-HIV, hypoglycemic and immunological activities, and so on. In this paper, the various aspects of the investigation results of tea polysaccharides in the past 20 years were summarized, including the extraction and purification processes, the structure and bioactivities. © 2010 Elsevier Ltd.

Li H.,Nanchang University | Li H.,Agriculture and Agri Food Canada | Deng Z.,Nanchang University | Wu T.,CAS Xinjiang Technical Institute of Physics and Chemistry | And 3 more authors.
Food Chemistry | Year: 2012

Microwave-assisted extraction (MAE) was investigated for extraction of phenolic compounds from tomato with maximised antioxidant activities using response surface methodology (RSM) coupled with a central composite design, and in vitro antioxidant assays (FRAP and ORAC). MAE was more efficient for greater antioxidant activities and higher total phenolic contents than solvent extraction. The optimal MAE processing parameters were 96.5 °C, 2.06 min, 66.2% ethanol for FRAP, and 96.5 °C, 1.66 min, 61.1% ethanol for ORAC. The models were successfully applied to 20 tomato cultivars, whose total phenolic contents (TPC) and indexes (TPI) were 489.30-997.45 mg gallic acid equivalent/100 g dry weight (DW) and 281.34-468.52 mg/100 g DW, respectively. Eight phenolic compounds were identified. Individual phenolics were 6.10-42.73 mg/100 g DW. The FRAP, but not the ORAC value showed good correlation with the TPC or TPI. The methodologies developed and the knowledge acquired in this study will provide useful information to tomato breeders and food processors. © 2011 Published by Elsevier Ltd. All rights reserved.

Li X.-Q.,Agriculture and Agri Food Canada | Du D.,University of New Brunswick
PLoS ONE | Year: 2014

C+G content (GC content or G+C content) is known to be correlated with genome/chromosome size in bacteria but the relationship for other kingdoms remains unclear. This study analyzed genome size, chromosome size, and base composition in most of the available sequenced genomes in various kingdoms. Genome size tends to increase during evolution in plants and animals, and the same is likely true for bacteria. The genomic C+G contents were found to vary greatly in microorganisms but were quite similar within each animal or plant subkingdom. In animals and plants, the C+G contents are ranked as follows: monocot plants>mammals>non-mammalian animals>dicot plants. The variation in C+G content between chromosomes within species is greater in animals than in plants. The correlation between average chromosome C+G content and chromosome length was found to be positive in Proteobacteria, Actinobacteria (but not in other analyzed bacterial phyla), Ascomycota fungi, and likely also in some plants; negative in some animals, insignificant in two protist phyla, and likely very weak in Archaea. Clearly, correlations between C+G content and chromosome size can be positive, negative, or not significant depending on the kingdoms/groups or species. Different phyla or species exhibit different patterns of correlation between chromosome-size and C+G content. Most chromosomes within a species have a similar pattern of variation in C+G content but outliers are common. The data presented in this study suggest that the C+G content is under genetic control by both trans- and cis- factors and that the correlation between C+G content and chromosome length can be positive, negative, or not significant in different phyla. © 2014 Li, Du.

Sutherland A.B.,University of New Brunswick | Culp J.M.,University of New Brunswick | Benoy G.A.,Agriculture and Agri Food Canada
Limnology and Oceanography: Methods | Year: 2010

Numerous techniques are used to measure deposited sediment and quantify substrate quality in streams. We evaluated the relationship between land disturbance and stream habitat by comparing 25 commonly used deposited sediment parameters to watershed, riparian, and local-scale drivers. We also tested whether land use regressions were improved by accounting for geomorphic setting (measures of slope and channel incision) and how visual versus measurement-based estimations of percent fines and embeddedness were related to each other and to percent agriculture. Of the 16 metrics significantly related to watershed agriculture, subsurface percent fines was the best indicator of land use. Subsurface fines were more strongly related to both watershed and riparian percent agriculture than surface sediment metrics. The second best-performing parameter was the visual assessment of percent fines <2mm. Surface particle counts also performed moderately well. Sediment percentiles (d50, d84) and stability indices were among the weakest indicators of watershed land use. All measures of local percent agriculture were poor predictors of deposited sediment parameters. Mean slope within the entire stream network was nearly as good of a predictor of deposited sediment as watershed percent agriculture. This suggests that we may improve our ability to predict deposited sediment by considering land use within the appropriate geomorphic context. © 2010, by the American Society of Limnology and Oceanography, Inc.

Hugelius G.,University of Stockholm | Kuhry P.,University of Stockholm | Tarnocai C.,Agriculture and Agri Food Canada | Virtanen T.,University of Helsinki
Permafrost and Periglacial Processes | Year: 2010

We investigated total storage and landscape partitioning of soil organic carbon (SOC) in continuous permafrost terrain, central Canadian Arctic. The study is based on soil chemical analyses of pedons sampled to 1-m depth at 35 individual sites along three transects. Radiocarbon dating of cryoturbated soil pockets, basal peat and fossil wood shows that cryoturbation processes have been occurring since the Middle Holocene and that peat deposits started to accumulate in a forest-tundra environment where spruce was present (~6000 cal yrs BP). Detailed partitioning of SOC into surface organic horizons, cryoturbated soil pockets and non-cryoturbated mineral soil horizons is calculated (with storage in active layer and permafrost calculated separately) and explored using principal component analysis. The detailed partitioning and mean storage of SOC in the landscape are estimated from transect vegetation inventories and a land cover classification based on a Landsat satellite image. Mean SOC storage in the 0-100-cm depth interval is 33.8kg Cm 2, of which 11.8 kg C m 2 is in permafrost. Fifty-six per cent of the total SOC mass is stored in peatlands (mainly bogs), but cryoturbated soil pockets in Turbic Cryosols also contribute significantly (17%). Elemental C/N ratios indicate that this cryoturbated soil organic matter (SOM) decomposes more slowly than SOM in surface O-horizons. © 2010 John Wiley & Sons, Ltd.

Goyal R.K.,Agriculture and Agri Food Canada | Mattoo A.K.,U.S. Department of Agriculture
Plant Science | Year: 2014

Crop losses due to pathogens are a major threat to global food security. Plants employ a multilayer defense against a pathogen including the use of physical barriers (cell wall), induction of hypersensitive defense response (HR), resistance (R) proteins, and synthesis of antimicrobial peptides (AMPs). Unlike a complex R gene-mediated immunity, AMPs directly target diverse microbial pathogens. Many a times, R-mediated immunity breaks down and plant defense is compromised. Although R-gene dependent pathogen resistance has been well studied, comparatively little is known about the interactions of AMPs with host defense and physiology. AMPs are ubiquitous, low molecular weight peptides that display broad spectrum resistance against bacteria, fungi and viruses. In plants, AMPs are mainly classified into cyclotides, defensins, thionins, lipid transfer proteins, snakins, and hevein-like vicilin-like and knottins. Genetic distance lineages suggest their conservation with minimal effect of speciation events during evolution. AMPs provide durable resistance in plants through a combination of membrane lysis and cellular toxicity of the pathogen. Plant hormones - gibberellins, ethylene, jasmonates, and salicylic acid, are among the physiological regulators that regulate the expression of AMPs. Transgenically produced AMP-plants have become a means showing that AMPs are able to mitigate host defense responses while providing durable resistance against pathogens. © 2014.Published by Elsevier Ireland Ltd.

Shaner D.L.,U.S. Department of Agriculture | Beckie H.J.,Agriculture and Agri Food Canada
Pest Management Science | Year: 2014

This review is both a retrospective (what have we missed?) and prospective (where are we going?) examination of weed control and technology, particularly as it applies to herbicide-resistant weed management (RWM). Major obstacles to RWM are discussed, including lack of diversity in weed management, unwillingness of many weed researchers to conduct real integrated weed management research or growers to accept recommendations, influence or role of agrichemical marketing and governmental policy and lack of multidisciplinary research. We then look ahead to new technologies that are needed for future weed control in general and RWM in particular, in areas such as non-chemical and chemical weed management, novel herbicides, site-specific weed management, drones for monitoring large areas, wider application of 'omics' and simulation model development. Finally, we discuss implementation strategies for integrated weed management to achieve RWM, development of RWM for developing countries, a new classification of herbicides based on mode of metabolism to facilitate greater stewardship and greater global exchange of information to focus efforts on areas that maximize progress in weed control and RWM. There is little doubt that new or emerging technologies will provide novel tools for RMW in the future, but will they arrive in time? © 2013 Society of Chemical Industry.

Champagne C.P.,Agriculture and Agri Food Canada | Ross R.P.,Teagasc | Saarela M.,VTT Technical Research Center of Finland | Hansen K.F.,Chr. Hansens | Charalampopoulos D.,University of Reading
International Journal of Food Microbiology | Year: 2011

Due to the fact that probiotic cells need to be alive when they are consumed, culture-based analysis (plate count) is critical in ascertaining the quality (numbers of viable cells) of probiotic products. Since probiotic cells are typically stressed, due to various factors related to their production, processing and formulation, the standard methodology for total plate counts tends to underestimate the cell numbers of these products. Furthermore, products such as microencapsulated cultures require modifications in the release and sampling procedure in order to correctly estimate viable counts. This review examines the enumeration of probiotic bacteria in the following commercial products: powders, microencapsulated cultures, frozen concentrates, capsules, foods and beverages. The parameters which are specifically examined include: sample preparation (rehydration, thawing), dilutions (homogenization, media) and plating (media, incubation) procedures. Recommendations are provided for each of these analytical steps to improve the accuracy of the analysis. Although the recommendations specifically target the analysis of probiotics, many will apply to the analysis of commercial lactic starter cultures used in food fermentations as well. © 2011.

Redhead S.A.,Agriculture and Agri Food Canada | Norvell L.L.,Pacific Northwest Mycology Service
Taxon | Year: 2013

The Committee supports recognition of multiple official repositories over a single repository, and accepted three: Fungal Names, Index Fungorum, and MycoBank starting 1 January 2013, noting that parties representing the three have signed a Memorandum of Cooperation that expires immediately following the next International Botanical Congress in 2017. The effectiveness of this arrangement will be evaluated and reviewed by 2014 when the International Mycological Congress must ratify the NCF recommendations.

Wang T.-C.,Henan Agricultural University | Wei L.,Henan Agricultural University | Wang H.-Z.,Chinese Academy of Agricultural Sciences | Ma S.-C.,Henan Polytechnic University | Ma B.L.,Agriculture and Agri Food Canada
Field Crops Research | Year: 2011

In the rain-fed areas of northern China, maize (Zea mays L.) is a main field crop, as it is well adapted to high temperatures and bright sunshine. However, low and variable rainfall and high evapotranspiration rates are common in water-limited environments during the growing season, and often mismatched rainfall events with the critical growth stages, making yield unstable. In this study, the performance of a furrow-planting and straw-mulching system was compared with the conventional flat-planting system in a double-crop culture of winter wheat (Triticum aestivum L.) and summer maize for two consecutive years (2005-2006 and 2006-2007). The four tested treatments were: conventional flat planting (F), furrow planting between ridges (B), flat planting with wheat straw-mulching (FS), and furrow planting between ridges with wheat-straw mulch (BS). Soil water content and leaf area index (LAI) were measured throughout the growing season each year, and grain yield and precipitation-use efficiency (PUEY) were determined.On average, ridge tillage combined with furrow planting increased maize yield by 430kgha-1 (7.3%) and PUEY by 10.7% (1.5kgha-1mm-1), compared with the conventional flat planting; furrow planting coupled with straw mulching increased yield by an additional 16.9% and PUEY by 19.4%, respectively. From jointing to maturity, LAI values of BS were significantly higher than those of F-system (55.6% vs. 26.1% in 2006 and 81.4% vs. 21.7% in 2007). Our data suggest that maize production adopted by furrow planting with straw-covered ridges performed best under seasonal average rainfall below 480mm, which was associated with better synchronization of seasonal soil water supply and crop needs, leading to improved maize yield and PUEY. © 2011.

Levy D.,Hebrew University of Jerusalem | Coleman W.K.,Agriculture and Agri Food Canada | Veilleux R.E.,Virginia Polytechnic Institute and State University
American Journal of Potato Research | Year: 2013

Agriculture that depends upon irrigation is challenged by the increasing scarcity of fresh water and global climate change, and increasing human populations aggravate this situation. The potato crop depends on a regular water supply to secure high quality yields. Abiotic stress factors, such as drought, heat and salinity, have severe, adverse effects on growth and yield. In this review, different approaches to cope with water stress are presented. These approaches include altering morphological, physiological and genetic characteristics of potato and the use of biotechnology. For example, native potato and alien genes have been identified by transcriptomics and may provide useful candidates for deployment against stress. Transgenic potato cultivars harboring many of these genes have been evaluated and show promise for future release as new, stress tolerant cultivars. Potential management tools for economizing water use include efficient irrigation systems and precision agriculture. The use of alternative water resources, such as greywater, recycled wastewater, agricultural drainage water, and desalinated water will contribute to the water requirements of the potato crop and should help meet future challenges. © 2013 Potato Association of America.

Rawson A.,National University of Ireland | Patras A.,University of Guelph | Tiwari B.K.,Manchester Metropolitan University | Noci F.,University College Dublin | And 2 more authors.
Food Research International | Year: 2011

Exotic fruits play a vital role in human diet due to the presence of bioactive compounds. Recent research shows the importance of phytochemicals and antioxidants in human health and nutrition. This review summarizes the recent application of both thermal and non-thermal processing technologies on bioactive content of exotic fruits and their products. This review also discusses the impact of processing conditions on the stability of bioactive compounds in exotic fruits and their products. The information provided will be beneficial for further commercialization and exploration of these novel technologies. © 2011 Elsevier Ltd.

Andrew M.E.,Natural Resources Canada | Wulder M.A.,Natural Resources Canada | Coops N.C.,University of British Columbia | Baillargeon G.,Agriculture and Agri Food Canada
Global Ecology and Biogeography | Year: 2012

Aim: Several lines of evidence suggest that beta diversity, or dissimilarity in species composition, should increase with productivity: (1) the latitudinal species richness gradient is most closely related to productivity and associated latitudinal beta-diversity relationships have been described, and (2) the scale dependence of the productivity-diversity relationship implies that there should be a positive productivity-beta-diversity relationship. However, such a pattern has not yet been demonstrated at broad scales. We test if there is a gradient of increasing beta diversity with productivity. Location: Canada. Methods: Canada was clustered into regions of similar productivity regimes along three remotely sensed productivity axes (minimum and integrated annual productivity, seasonality of productivity) and elevation. The overall (β j), turnover (β sim) and nestedness (β nes) components of beta diversity within each productivity regime were estimated with pairwise dissimilarity metrics and related to cluster productivity with partial linear regression and with spatial autoregression. Tests were performed for all species, productivity breadth-based subsets (e.g. species occurring in many and a moderate number of productivity regimes), and pre- and post-1970 butterfly records. Beta diversity between adjacent clusters along the productivity gradients was also evaluated. Results: Within-cluster β j and β sim increased with productivity and decreased with seasonality. The converse was true for β nes. All species subsets responded similarly; however, productivity-beta-diversity relationships were weaker for the post-1970 temporal subset and strongest for species of moderate breadth. Between-cluster beta diversity (β j) and nestedness (β nes) declined with productivity. Main conclusions: As predicted, beta diversity of communities within productivity regimes was observed to increase with productivity. This pattern was driven largely by a gradient of species turnover. Therefore, beta diversity may make an important contribution to the broad-scale gradient of species richness with productivity. However, this species richness gradient dominates regional beta diversity between productivity regimes, resulting in decreasing between-productivity dissimilarity with productivity driven by a concurrent decline in nestedness. © 2011 Crown in the right of Canada.

King R.R.,Agriculture and Agri Food Canada | Calhoun L.A.,University of New Brunswick
Magnetic Resonance in Chemistry | Year: 2012

The normal levels and types of glycoalkaloids found in commercial varieties of potato (Solanum tuberosum) appear to present no hazard to human health. However when wild Solanum species are used in breeding endeavors, new and untested glycoalkaloids may be introduced. Recent studies of domestic crosses with a wild Solanum oplocense accession indicated that the levels of a non-indigenous glycoalkaloid appeared associated with reduced defoliation by the Colorado potato beetle. The non-indigenous glycoalkaloid was isolated from foliage of the wild S. oplocense accession and unambiguously characterized by high-resolution electrospray ionization mass spectrometry and NM analysis as the glycoalkaloid dehydrocommersonine. Copyright © 2012 John Wiley & Sons, Ltd.

He Z.,Southern Regional Research Center | Olk D.C.,U.S. Department of Agriculture | Cade-Menun B.J.,Agriculture and Agri Food Canada
Soil Science Society of America Journal | Year: 2011

Phosphorus has long been known to be present in soil humic fractions, but little is known about specific P forms in humic fractions or their lability. We extracted the mobile humic acid (MHA) and recalcitrant calcium humate (CaHA) fractions from a Nebraska Hord silt loam soil (a fine-silty, mixed, superactive, mesic Cumulic Haplustoll) under continuous corn (Zea mays L.) receiving either inorganic fertilizer or animal manure. Solution 31P nuclear magnetic resonance spectroscopy demonstrated that P in both MHA and CaHA was predominantly present in organic forms, mostly as orthophosphate monoesters. Spiking experiments indicated no phytate present in these humic fractions, but scyllo-inositol P was identified in all samples. Potato phosphatase hydrolyzed some humicbound P. Fungal phytase released more humic-bound P, which may come from scyllo-inositol P. No additional P was released by including nuclease. Ultraviolet (UV) irradiation increased soluble inorganic P in MHA fractions, but total hydrolyzable P in MHA fractions did not increase, suggesting that the portion of P that was UV labile was also enzymatically hydrolyzable. In contrast, UV irradiation increased soluble inorganic P and total hydrolysable P in CaHA fractions, which suggests that UV-labile P in CaHA fractions did not overlap wiThenzymatically hydrolyzable P. Fertilization management did not significantly alter the lability of humic P in these humic fractions. This research has the potential to improve P management by increasing our knowledge of P lability for more efficient crop uptake. © Soil Science Society of America.

Keller S.R.,University of Minnesota | Olson M.S.,University of Alaska Fairbanks | Salim S.,Agriculture and Agri Food Canada | William S.A.,Agriculture and Agri Food Canada | Peter T.,University of Minnesota
Molecular Ecology | Year: 2010

Rapid range expansions can cause pervasive changes in the genetic diversity and structure of populations. The postglacial history of the Balsam Poplar, Populus balsamifera, involved the colonization of most of northern North America, an area largely covered by continental ice sheets during the last glacial maximum. To characterize how this expansion shaped genomic diversity within and among populations, we developed 412 SNP markers that we assayed for a range-wide sample of 474 individuals sampled from 34 populations. We complemented the SNP data set with DNA sequence data from 11 nuclear loci from 94 individuals, and used coalescent analyses to estimate historical population size, demographic growth, and patterns of migration. Bayesian clustering identified three geographically separated demes found in the Northern, Central, and Eastern portions of the species' range. These demes varied significantly in nucleotide diversity, the abundance of private polymorphisms, and population substructure. Most measures supported the Central deme as descended from the primary refuge of diversity. Both SNPs and sequence data suggested recent population growth, and coalescent analyses of historical migration suggested a massive expansion from the Centre to the North and East. Collectively, these data demonstrate the strong influence that range expansions exert on genomic diversity, both within local populations and across the range. Our results suggest that an in-depth knowledge of nucleotide diversity following expansion requires sampling within multiple populations, and highlight the utility of combining insights from different data types in population genomic studies. © 2010 Blackwell Publishing Ltd.

Olson M.S.,University of Alaska Fairbanks | Robertson A.L.,University of Alaska Fairbanks | Takebayashi N.,University of Alaska Fairbanks | Silim S.,Agriculture and Agri Food Canada | And 2 more authors.
New Phytologist | Year: 2010

Current perceptions that poplars have high levels of nucleotide variation, large effective population sizes, and rapid decay of linkage disequilibrium are based primarily on studies from one poplar species, Populus tremula. We analysed 590 gene fragments (average length 565bp) from each of 15 individuals from different populations from throughout the range of Populus balsamifera. Nucleotide diversity (Θtotal = 0.0028, π = 0.0027) was low compared with other trees and model agricultural systems. Patterns of nucleotide diversity and site frequency spectra were consistent with purifying selection on replacement and intron sites. When averaged across all loci we found no evidence for decay of linkage disequilibrium across 750bp, consistent with the low estimates of the scaled recombination parameter, ρ = 0.0092. Compared with P. tremula, a well studied congener with a similar distribution, P. balsamifera has low diversity and low effective recombination, both of which indicate a lower effective population size in P. balsamifera. Patterns of diversity and linkage indicate that there is considerable variation in population genomic patterns among poplar species and unlike P. tremula, association mapping techniques in balsam poplar should consider sampling single nucleotide polymorphisms (SNPs) at well-spaced intervals. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Wang S.,Natural Resources Canada | McKenney D.W.,Natural Resources Canada | Shang J.,Agriculture and Agri Food Canada | Li J.,Natural Resources Canada
Journal of Geophysical Research D: Atmospheres | Year: 2014

This study examined the long-term water budget closures for 370 watersheds over Canada's landmass by using 30years' (1981-2010) data products recently produced for precipitation (P) gridded using climate station measurements, land surface evapotranspiration (ET), and water surface evaporation (E0) obtained by the Ecological Assimilation of Land and Climate Observations (EALCO) model, and observed streamflow (Q). The results show that 29%, 58%, and 83% of the watersheds were closed within 5%, 10%, and 20% of P, respectively. The positive and negative imbalances among the 370 watersheds are largely offset and the national scale average is 24 mm yr-1, or 4.2% of P. Water budget closures have large variation across the landmass. Regions with sparse or less accurate monitoring of P such as the mountainous region and the Arctic exhibit the largest water imbalances. Further efforts on enhancing the climate observation networks, improving spatial models for P and ET estimates, and streamflow measurements are all likely critical for a better understanding of Canada's water budgets. © 2014 Her Majesty the Queen in Right of Canada.

Barra Caracciolo A.,CNR Water Research Institute | Topp E.,Agriculture and Agri Food Canada | Grenni P.,CNR Water Research Institute
Journal of Pharmaceutical and Biomedical Analysis | Year: 2015

Environmental microorganisms play a key role in fundamental ecological processes such as biogeochemical cycling and organic contaminant degradation. Microorganisms comprise a large unexplored reservoir of genetic diversity and metabolic capability providing several ecosystem services, most importantly the maintenance of soil and water quality. Pharmaceutical occurrence in the environment can compromise microbial community structure and activities in different ways. The fate of a pharmaceutical in soil or water depends on numerous factors, including its inherent physic-chemical properties (e.g. water solubility, lipophilicity, vapour pressure), environmental factors and climate conditions (e.g. temperature, incident radiation, pH) and most importantly the presence and activity of microorganisms that possess the ability to biodegrade it. The presence of a natural microbial community is a necessary prerequisite for an effective response to the various chemicals that can contaminate an ecosystem. The recovery from contamination is only possible if toxicity does not hamper microbial activity. This review presents current knowledge on the effects on natural microbial communities of some pharmaceuticals and of some biocides commonly found as environmental microcontaminants. © 2014 Elsevier B.V.

Thrall P.H.,CSIRO | Laine A.-L.,CSIRO | Laine A.-L.,University of Helsinki | Ravensdale M.,CSIRO | And 5 more authors.
Ecology Letters | Year: 2012

Antagonistic coevolution is a critical force driving the evolution of diversity, yet the selective processes underpinning reciprocal adaptive changes in nature are not well understood. Local adaptation studies demonstrate partner impacts on fitness and adaptive change, but do not directly expose genetic processes predicted by theory. Specifically, we have little knowledge of the relative importance of fluctuating selection vs. arms-race dynamics in maintaining polymorphism in natural systems where metapopulation processes predominate. We conducted cross-year epidemiological, infection and genetic studies of multiple wild host and pathogen populations in the Linum-Melampsora association. We observed asynchronous phenotypic fluctuations in resistance and infectivity among demes. Importantly, changes in allelic frequencies at pathogen infectivity loci, and in host recognition of these genetic variants, correlated with disease prevalence during natural epidemics. These data strongly support reciprocal coevolution maintaining balanced resistance and infectivity polymorphisms, and highlight the importance of characterising spatial and temporal dynamics in antagonistic interactions. © 2012 Blackwell Publishing Ltd/CNRS.

O'Rourke S.M.,University College Dublin | O'Rourke S.M.,University of Sydney | Angers D.A.,Agriculture and Agri Food Canada | Holden N.M.,University College Dublin | Mcbratney A.B.,University of Sydney
Global Change Biology | Year: 2015

Mechanistic understanding of scale effects is important for interpreting the processes that control the global carbon cycle. Greater attention should be given to scale in soil organic carbon (SOC) science so that we can devise better policy to protect/enhance existing SOC stocks and ensure sustainable use of soils. Global issues such as climate change require consideration of SOC stock changes at the global and biosphere scale, but human interaction occurs at the landscape scale, with consequences at the pedon, aggregate and particle scales. This review evaluates our understanding of SOC across all these scales in the context of the processes involved in SOC cycling at each scale and with emphasis on stabilizing SOC. Current synergy between science and policy is explored at each scale to determine how well each is represented in the management of SOC. An outline of how SOC might be integrated into a framework of soil security is examined. We conclude that SOC processes at the biosphere to biome scales are not well understood. Instead, SOC has come to be viewed as a large-scale pool subjects to carbon flux. Better understanding exists for SOC processes operating at the scales of the pedon, aggregate and particle. At the landscape scale, the influence of large- and small-scale processes has the greatest interaction and is exposed to the greatest modification through agricultural management. Policy implemented at regional or national scale tends to focus at the landscape scale without due consideration of the larger scale factors controlling SOC or the impacts of policy for SOC at the smaller SOC scales. What is required is a framework that can be integrated across a continuum of scales to optimize SOC management. © 2015 John Wiley & Sons Ltd.

Olson M.S.,Texas Tech University | Olson M.S.,University of Alaska Fairbanks | Levsen N.,University of Alaska Fairbanks | Soolanayakanahally R.Y.,Agriculture and Agri Food Canada | And 4 more authors.
Molecular Ecology | Year: 2013

The manner in which organisms adapt to climate change informs a broader understanding of the evolution of biodiversity as well as conservation and mitigation plans. We apply common garden and association mapping approaches to quantify genetic variance and identify loci affecting bud flush and bud set, traits that define a tree's season for height growth, in the boreal forest tree Populus balsamifera L. (balsam poplar). Using data from 478 genotypes grown in each of two common gardens, one near the southern edge and another near the northern edge of P. balsamifera's range, we found that broad-sense heritability for bud flush and bud set was generally high (H2 > 0.5 in most cases), suggesting that abundant genetic variation exists for phenological response to changes in the length of the growing season. To identify the molecular genetic basis of this variation, we genotyped trees for 346 candidate single nucleotide polymorphisms (SNPs) from 27 candidate genes for the CO/FT pathway in poplar. Mixed-model analyses of variance identified SNPs in 10 genes to be associated with variation in either bud flush or bud set. Multiple SNPs within FRIGIDA were associated with bud flush, whereas multiple SNPs in LEAFY and GIGANTEA 5 were associated with bud set. Although there was strong population structure in stem phenology, the geographic distribution of multilocus association SNP genotypes was widespread except at the most northern populations, indicating that geographic regions may harbour sufficient diversity in functional genes to facilitate adaption to future climatic conditions in many sites. © 2012 Blackwell Publishing Ltd.

Nangia V.,Agriculture and Agri Food Canada | Mulla D.J.,University of Minnesota | Gowda P.H.,U.S. Department of Agriculture
Journal of Environmental Quality | Year: 2010

Nitrate-N losses to surface waters in the Upper Midwest of the Untied States have increased in recent decades, contributing to hypoxia in the Gulf of Mexico. Th is paper investigates whetherincreasing nitrate-N export from cropland in the Upper Midwest since the late 1960s results from changes in land use or climate. The Agricultural Drainage and Pesticide Transport (ADAPT) Model simulated current and historical agricultural systems under past and recent wet climate for Seven Mile Creek in Minnesota. Simulations were run with management and climate for three distinctly diff erent periods - namely, 1965 to 1969, 1976 to 1980, and 1999 to 2003 (wettest period). Results showed discharge and nitrate-N losses responded more to changes in climate than management. The wetter period (1999-2003) caused a simulated 70% increase in discharge under 1960s-era management compared with that period's observed climate and a simulated 51% increase in discharge under 1970s-era management compared with the 1976 to 1980 climate. The recent, wetter climate also produced a 62% increase in nitrate-N losses for 1960s-era management compared with the actual climate and a 137% increase in nitrate-N losses for 1978 management conditions compared with actual 1970s climate. Had recent climate been in place and stable since 1965, agricultural changes would have decreased discharge by 6.4% through the late 1970s and then by another 21.1% under modern management but would have increased nitrate-N losses by 184% through the late 1970s and then decreased nitrate-N losses by 13.5% between 1978 and 2001. Management changes that were important drivers included increasing N-fertilizer rates, increases in corn acreage, and increases in crop yield. But the most important factor driving increased nitrate-N losses from agriculture since the 1970s was an increasingly wetter climate. Copyright © 2010 by the American Society of Agronomy.

Shellie K.C.,U.S. Department of Agriculture | Bowen P.,Agriculture and Agri Food Canada
Irrigation Science | Year: 2014

Cabernet Sauvignon and Malbec grapevines were irrigated at 70 or 23 % of estimated crop evapotranspiration throughout berry development over four growing seasons. Stomatal behavior was characterized by relating predawn leaf water potential and mid-morning stomatal conductance to mid-morning leaf water potential. Seasonal average weekly midday leaf water potential was lower in Cabernet Sauvignon than Malbec despite similar irrigation amounts. Both cultivars exhibited anisohydric behavior with midday leaf water potential decreasing linearly with declining predawn leaf water potential (r 2 = 0.51) and stomatal conductance (r 2 = 0.42). However, both cultivars utilized hydrodynamic mechanisms to maintain a soil-to-leaf water potential gradient of -0.62 (±0.03) MPa under standard irrigation and -0.75 (±0.04) MPa under reduced irrigation. Berry fresh weight and titratable acidity decreased, and the concentration of total anthocyanins increased in both cultivars in response to decreases in midday leaf water potential. The slope of regression equations for seasonal mean midday leaf water potential was used to estimate cultivar-specific levels of water stress associated with changes in berry weight and berry composition at fruit maturity. © 2013 Springer-Verlag Berlin Heidelberg (outside the USA).

McCormick S.P.,U.S. Department of Agriculture | Alexander N.J.,U.S. Department of Agriculture | Harris L.J.,Agriculture and Agri Food Canada
Applied and Environmental Microbiology | Year: 2010

Fusarium graminearum is a fungal pathogen of cereal crops (e.g., wheat, barley, maize) and produces a number of mycotoxins, including 15-acetyIdeoxynivaIenoI, butenolide, zearalenone, and culmorin. To identify a biosynthetic gene for the culmorin pathway, an expressed-sequence-tag database was examined for terpene cyclase genes. A gene designated CLM1 was expressed under trichothecene-inducing conditions. Expression of CLM1 in yeast (Saccharomyces cerevisiae) resulted in the production of a sesquiterpene alcohol, longiborneol, which has the same ring structure as culmorin. Gene disruption and add-back experiments in F. graminearum showed that CLM1 was required for culmorin biosynthesis. CLM1 gene disruptants were able to convert exogenously added longiborneol to culmorin. Longiborneol accumulated transiently in culmorin-producing strains. The results indicate that CLMl encodes a longiborneol synthase and is required for culmorin biosynthesis in F. graminearum. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Pastell M.,University of Helsinki | Hanninen L.,University of Helsinki | de Passille A.M.,Agriculture and Agri Food Canada | Rushen J.,Agriculture and Agri Food Canada
Journal of Dairy Science | Year: 2010

There is increasing interest in automated methods of detecting lame cows. Hoof lesion data and measures of weight distribution from 61 lactating cows were examined in this study. Lame cows were identified with different numerical rating scores (NRS) used as thresholds (NRS >3 and NRS ≥3.5) for lameness. The ratio of weight applied to a pair of legs (LWR) when the cow was standing was calculated using a special weigh scale, and the cows were gait scored using a 1 to 5 NRS. Hoof lesions were scored and the cows placed into 1 of 4 mutually exclusive categories of hoof lesion: a) no lesions, b) moderate or severe hemorrhages, c) digital dermatitis, and d) sole ulcers. Regression analysis and receiver operating characteristic (ROC) curves were used to analyze the relation between hoof lesions and LWR. A clear relationship was found between NRS and LWR for the cows with sole ulcers (R2=0.79). The LWR could differentiate cows with sole ulcers from sound cows with no hoof lesions [area under the curve (AUC)=0.87] and lame cows from nonlame cows with lameness thresholds NRS >3 (AUC=0.71) and NRS ≥3.5 (AUC=0.88). There was no relationship between LWR and NRS for cows with digital dermatitis. Measurement of how cows distribute their weight when standing holds promise as a method of automated detection of lameness. © 2010 American Dairy Science Association.

Betts A.K.,U.S. National Center for Atmospheric Research | Desjardins R.,Agriculture and Agri Food Canada | Worth D.,Agriculture and Agri Food Canada | Wang S.,Natural Resources Canada | Li J.,Natural Resources Canada
Journal of Geophysical Research: Atmospheres | Year: 2014

Using data from 13 climate stations on the Canadian Prairies, together with opaque cloud cover and daily snow depth, to analyze the winter climate transitions with snow, we find that a snow cover acts as a fast climate switch. Surface temperature falls by about 10 K with fresh snowfall and rises by a similar amount with snowmelt, while the daily range of relative humidity falls to around 5-15% with snow cover. These are robust climate signals. For every 10% decrease in days with snow cover over the Canadian Prairies, the mean October to April climate is warmer by about 1.4 K. Stratifying by daily mean opaque cloud cover across snow transitions shows the rapid shift within 5 days from a diurnal cycle dominated by shortwave cloud forcing to one dominated by longwave cloud forcing. We calculate the change in the surface radiative budget with snow using surface albedo data from the Moderate Resolution Imaging Spectroradiometer and station longwave data. We find that with the fall-winter snow transitions, the surface radiative heating is reduced by 50 Wm -2, with 69% coming from the reduced net shortwave flux, resulting from the increased surface albedo and a small increase in effective cloud albedo, and 31% from a reduced incoming longwave flux. This drop in surface radiative heating is sufficient to produce a drop in the surface radiometric skin temperature of 11 K. We find that in winter, the monthly mean diurnal climate is more closely coupled to the diurnal shortwave forcing than the mean diurnal climate. Key Points Temperature changes by 10K with the spring and fall snow transitions A 10% decrease in days with snow cover increases winter temperatures by 1.4K With snow cover longwave cloud forcing dominates the diurnal cycle ©2014. Her Majesty the Queen in Right of Canada. American Geophysical Union. Reproduced with permission of the Minister of Agriculture and Agri-Food Canada.

Laganiere J.,Natural Resources Canada | Laganiere J.,University of Quebec at Montréal | Angers D.A.,Agriculture and Agri Food Canada | Pare D.,Natural Resources Canada | Pare D.,University of Quebec at Montréal
Global Change Biology | Year: 2010

Deforestation usually results in significant losses of soil organic carbon (SOC). The rate and factors determining the recovery of this C pool with afforestation are still poorly understood. This paper provides a review of the influence of afforestation on SOC stocks based on a meta-analysis of 33 recent publications (totaling 120 sites and 189 observations), with the aim of determining the factors responsible for the restoration of SOC following afforestation. Based on a mixed linear model, the meta-analysis indicates that the main factors that contribute to restoring SOC stocks after afforestation are: previous land use, tree species planted, soil clay content, preplanting disturbance and, to a lesser extent, climatic zone. Specifically, this meta-analysis (1) indicates that the positive impact of afforestation on SOC stocks is more pronounced in cropland soils than in pastures or natural grasslands; (2) suggests that broadleaf tree species have a greater capacity to accumulate SOC than coniferous species; (3) underscores that afforestation using pine species does not result in a net loss of the whole soil-profile carbon stocks compared with initial values (agricultural soil) when the surface organic layer is included in the accounting; (4) demonstrates that clay-rich soils (>33%) have a greater capacity to accumulate SOC than soils with a lower clay content (<33%); (5) indicates that minimizing preplanting disturbances may increase the rate at which SOC stocks are replenished; and (6) suggests that afforestation carried out in the boreal climate zone results in small SOC losses compared with other climate zones, probably because trees grow more slowly under these conditions, although this does not rule out gains over time after the conversion. This study also highlights the importance of the methodological approach used when developing the sampling design, especially the inclusion of the organic layer in the accounting. © 2009 Blackwell Publishing Ltd.

Li X.-Q.,Agriculture and Agri Food Canada | Du D.,University of New Brunswick
PLoS ONE | Year: 2013

Pre-messenger RNA (mRNA) 3′-end cleavage and subsequent polyadenylation strongly regulate gene expression. In comparison with the upstream or downstream motifs, relatively little is known about the feature differences of polyadenylation [poly(A)] sites among major kingdoms. We suspect that the precise poly(A) sites are very selective, and we therefore mapped mRNA poly(A) sites on complete and nearly complete genomes using mRNA sequences available in the National Center for Biotechnology Information (NCBI) Nucleotide database. In this paper, we describe the mRNA nucleotide [i.e., the poly(A) tail attachment position] that is directly in attachment with the poly(A) tail and the pre-mRNA nucleotide [i.e., the poly(A) tail starting position] that corresponds to the first adenosine of the poly(A) tail in the 29 most-mapped species (2 fungi, 2 protists, 18 animals, and 7 plants). The most representative pre-mRNA dinucleotides covering these two positions were UA, CA, and GA in 17, 10, and 2 of the species, respectively. The pre-mRNA nucleotide at the poly(A) tail starting position was typically an adenosine [i.e., A-type poly(A) sites], sometimes a uridine, and occasionally a cytidine or guanosine. The order was U>C>G at the attachment position but A>>U>C≥G at the starting position. However, in comparison with the mRNA nucleotide composition (base composition), the poly(A) tail attachment position selected C over U in plants and both C and G over U in animals, in both A-type and non-A-type poly(A) sites. Animals, dicot plants, and monocot plants had clear differences in C/G ratios at the poly(A) tail attachment position of the non-A-type poly(A) sites. This study of poly(A) site evolution indicated that the two positions within poly(A) sites had distinct nucleotide compositions and were different among kingdoms. © 2013 Li, Du.

Fageria M.S.,University of New Brunswick | Fageria M.S.,Agriculture and Agri Food Canada | Rajora O.P.,University of New Brunswick
Evolutionary Applications | Year: 2013

Forest harvesting of increasing intensities is expected to have intensifying impacts on the genetic diversity and population structure of postharvest naturally regenerated stands by affecting the magnitude of evolutionary processes, such as genetic drift, gene flow, mating system, and selection. We have tested this hypothesis for the first time by employing widely distributed boreal white spruce (Picea glauca) as a model and controlled, replicated experimental harvesting and regeneration experiment at the EMEND project site ( We used two approaches. First, genetic diversity and population structure of postharvest natural regeneration after five harvesting treatments (green tree retention of 75%, 50%, 20%, and 10%, and clearcut) were assessed and compared with those of the unharvested control (pristine preharvest old-growth) in two replicates each of conifer-dominated (CD) and mixed-wood (MW) forest, using 10 (six EST (expressed sequence tag) and four genomic) microsatellite markers. Second, genetic diversity and population structure of preharvest old-growth were compared with those of postharvest natural regeneration after five harvesting treatments in the same treatment blocks in one replicate each of CD and MW forests. Contrary to our expectations, genetic diversity, inbreeding levels, and population genetic structure were similar between unharvested control or preharvest old-growth and postharvest natural regeneration after five harvesting treatments, with clearcut showing no negative genetic impacts. The potential effects of genetic drift and inbreeding resulting from harvesting bottlenecks were counterbalanced by predominantly outcrossing mating system and high gene flow from the residual and/or surrounding white spruce. CD and MW forests responded similarly to harvesting of increasing intensities. Simulated data for 10, 50, and 100 microsatellite markers showed the same results as obtained empirically from 10 microsatellite markers. Similar patterns of genetic diversity and population structure were observed for EST and genomic microsatellites. In conclusion, harvesting of increasing intensities did not show any significant negative impact on genetic diversity, population structure, and evolutionary potential of white spruce in CD and MW forests. Our first of its kind of study addresses the broad central forest management question how forest harvesting and regeneration practices can best maintain genetic biodiversity and ecosystem integrity. © 2013 The Authors. Evolutionary Applications published by Blackwell Publishing Ltd.

Li X.-Q.,Agriculture and Agri Food Canada | Du D.,University of New Brunswick
BMC Evolutionary Biology | Year: 2014

Background: The polyadenylation of RNA is critical for gene functioning, but the conserved sequence motifs (often called signal or signature motifs), motif locations and abundances, and base composition patterns around mRNA polyadenylation [poly(A)] sites are still uncharacterized in most species. The evolutionary tendency for poly(A) site selection is still largely unknown. Results: We analyzed the poly(A) site regions of 31 species or phyla. Different groups of species showed different poly(A) signal motifs: UUACUU at the poly(A) site in the parasite Trypanosoma cruzi; UGUAAC (approximately 13 bases upstream of the site) in the alga Chlamydomonas reinhardtii; UGUUUG (or UGUUUGUU) at mainly the fourth base downstream of the poly(A) site in the parasite Blastocystis hominis; and AAUAAA at approximately 16 bases and approximately 19 bases upstream of the poly(A) site in animals and plants, respectively. Polyadenylation signal motifs are usually several hundred times more abundant around poly(A) sites than in whole genomes. These predominant motifs usually had very specific locations, whether upstream of, at, or downstream of poly(A) sites, depending on the species or phylum. The poly(A) site was usually an adenosine (A) in all analyzed species except for B. hominis, and there was weak A predominance in C. reinhardtii. Fungi, animals, plants, and the protist Phytophthora infestans shared a general base abundance pattern (or base composition pattern) of "U-rich - A-rich - U-rich - Poly(A) site - U-rich regions", or U-A-U-A-U for short, with some variation for each kingdom or subkingdom. Conclusion: This study identified the poly(A) signal motifs, motif locations, and base composition patterns around mRNA poly(A) sites in protists, fungi, plants, and animals and provided insight into poly(A) site evolution. © 2014 Li and Du; licensee BioMed Central Ltd.

Duplessis S.,CNRS Trees/Micro-organism Interactions | Bakkeren G.,Agriculture and Agri Food Canada | Hamelin R.,Natural Resources Canada | Hamelin R.,University of British Columbia
Advances in Botanical Research | Year: 2014

Pucciniales are an important group of fungal plant pathogens that cause rust diseases in a diverse group of hosts including ecologically and economically important crops and trees. Rust fungi have intriguing and complex life cycles and are obligate biotrophs. Because of their biological features, these fungi are very difficult to study under laboratory conditions. The recent advances in genomics and transcriptomics have opened great perspectives for making progress in the study of this group of fungi and more particularly to dissect the genetic determinants underlying the host infection process. In this chapter, we provide an overview of the current knowledge on rust genomics and we particularly highlight how next-generation sequencing technologies are moving this field forward, providing new avenues in the understanding of fungal biotrophy. © 2014 Elsevier Ltd.

Danielescu S.,University of New Brunswick | Danielescu S.,Agriculture and Agri Food Canada | MacQuarrie K.T.B.,University of New Brunswick
Biogeochemistry | Year: 2013

In Prince Edward Island, Canada, widespread intensive potato production has contributed to elevated nitrate concentrations in groundwater and streams, and eutrophic or anoxic conditions occur regularly in several estuarine systems. In this research, the stable isotopes of nitrogen and oxygen in nitrate in intertidal groundwater discharge and stream water were used, in conjunction with water quality and quantity data and land use information, to better understand the characteristics of nitrate delivered to two small estuaries with contrasting land use in their contributory catchments. Most of the water samples collected during the two-year study had isotopic signatures that fell in the range expected for nitrate derived from ammonium-based fertilizers (26.5 % of the samples) or in the overlapping range formed between ammonium-based fertilizers and nitrate derived from soil (64 % of the samples). Overall, isotopic signatures spanned over relatively narrow ranges, and correlations with other water quality parameters, or catchment characteristics, were weak. Nitrate in groundwater discharge and surface water in the Trout River catchment exhibited significantly different isotopic signatures only for the nitrogen isotope, while in the McIntyre Creek catchment groundwater discharge and surface water had similar isotopic signatures. When the isotopic results for the waters from the two catchments were compared, the surface waters were found to be similar, while the isotopic signatures of nitrate in groundwater were distinct only for the nitrogen isotope. Denitrification in the two study catchments was not evident based on the isotopic results for nitrate; however, in the case of the Trout River catchment, where a small freshwater pond exists, an average nitrate load reduction of 14 % was inferred based on a comparison of nitrate loads entering and leaving the pond. Overall, it appears that natural attenuation processes, occurring either in the streams or groundwater flow systems, do not significantly reduce nitrate loading to these estuaries. © 2013 Springer Science+Business Media Dordrecht.

Lee J.,U.S. Department of Agriculture | Dossett M.,Oregon State University | Dossett M.,Agriculture and Agri Food Canada | Finn C.E.,U.S. Department of Agriculture
Food Chemistry | Year: 2012

Here we attempt to clarify contemporary scientific findings of Rubus fruit phenolics, focusing mainly on published peer-reviewed work from the last 6 years. Our review focuses on research papers that identified phenolics of Rubus fruit, although other edible parts of Rubus plants (i.e. leaves, roots) also contain phenolics. With an increased awareness given to the potential health benefits of consuming berries high in phenolics, efforts have been directed at enhancing Rubus fruit quality and colour (through plant selection, harvesting, storage, etc.) for processors and consumers alike. Assessment of any progress requires knowing the state of the starting material, so effective research into Rubus phenolics relies upon the accurate identification of the components in Rubus fruit in the initial investigations. We have summarised these reports into three sections: anthocyanins, phenolic monomers other than anthocyanins, and phenolic polymers. More work is needed in identification and quantification, and further opportunities remain for deciphering and clarifying existing phenolic information for Rubus fruit. © 2011 Elsevier Ltd. All rights reserved.

Knight A.L.,U.S. Department of Agriculture | Light D.M.,U.S. Department of Agriculture | Trimble R.M.,Agriculture and Agri Food Canada
Environmental Entomology | Year: 2011

Laboratory and field studies were conducted to measure the responses of adult codling moth, Cydia pomonella (L.), to several plant volatiles presented alone and in combination with acetic acid. Plant volatiles included ethyl (E,Z)-2,4-decadienoate (pear ester), (E)-β-farnesene, (Z)-3-hexenyl acetate, ± farnesol, and (E)-4,8-dimethyl-l,3,7-nonatriene (DMNT). Male codling moth exhibited upwind behavioral responses to each compound in flight tunnel tests with acetic acid > DMNT > ± farnesol > (Z)-3-hexenyl acetate > pear ester > (E)-β-farnesene. In apple orchards, however, only pear ester was an effective lure when used alone with clear pane traps. Choice tests in a flight tunnel with delta traps baited with DMNT plus acetic acid caught significantly more male and females than unbaited traps and significantly more females than DMNT-baited traps. Combining pear ester or DMNT loaded in septa lures with separate vials containing acetic acid significantly increased both male and female moth catch compared with the plant volatile alone, acetic acid alone, and unbaited pane traps in field trials. Similar results were not obtained with the other three plant volatiles. Septum loadings of 1 and 10 mg with either pear ester or DMNT in combination with acetic acid caught similar numbers of moths in orange delta traps. Sixty to 75% of the moths captured in traps baited with DMNT plus acetic acid were females. Moth catches in traps baited with DMNT plus acetic acid were ≈ 40% of catches in similar traps baited with pear ester plus acetic acid. © 2011 Entomological Society of America.

Lester G.E.,U.S. Department of Agriculture | Makus D.J.,U.S. Department of Agriculture | Mark Hodges D.,Agriculture and Agri Food Canada
Journal of Agricultural and Food Chemistry | Year: 2010

Current retail marketing conditions allow produce to receive artificial light 24 h per day during its displayed shelf life. Essential human-health vitamins [ascorbic acid (vit C), folate (vit B9), phylloquinone (vit K1), α-tocopherol (vit E), and the carotenoids lutein, violaxanthin, zeaxanthin, and β-carotene (provit A)] also are essential for photosynthesis and are biosynthesized in plants by light conditions even under chilling temperatures. Spinach leaves, notably abundant in the aforementioned humanhealth compounds, were harvested from flat-leaf 'Lazio' and crinkle-leafed 'Samish' cultivars at peak whole-plant maturity as baby (top- and midcanopy) and larger (lower-canopy) leaves. Leaves were placed as a single layer in commercial, clear-polymer retail boxes and stored at 4 °C for up to 9 days under continuous light (26.9 μmol-m2 -s) or dark. Top-canopy, baby-leaf spinach generally had higher concentrations of all bioactive compounds, on a dry weight basis, with the exception of carotenoids, than bottom-canopy leaves. All leaves stored under continuous light generally had higher levels of all bioactive compounds, except β-carotene and violaxanthin, and were more prone to wilting, especially the flat-leafed cultivar. All leaves stored under continuous darkness had declining or unchanged levels of the aforementioned bioactive compounds. Findings from this study revealed that spinach leaves exposed to simulated retail continuous light at 4 °C, in clear plastic containers, were overall more nutritionally dense (enriched) than leaves exposed to continuous darkness.

Levy D.,Hebrew University of Jerusalem | Tai G.C.C.,Agriculture and Agri Food Canada
Agricultural Water Management | Year: 2013

Ten potato varieties, commonly grown in the Mediterranean region, were grown on sandy soil in an arid desert area of Israel. The potatoes were drip-irrigated with three water sources: fresh water (control - ENV1), saline water from a local well (intermediate salinity - ENV2) and the local well water enriched with NaCl (high salinity - ENV3). The average salinity levels expressed as the electrical conductivity (EC) measured in the soil extracts from the root zone were 2.35, 5.1 and 8.5dSm-1 for the ENV1, ENV2 and ENV3 treatments, respectively. Salinity stress decreased fresh tuber yields, increased tuber dry matter and soluble solids, increased tuber electrolyte content and lowered osmotic potential (OP) of the tuber sap in all varieties. ANOVA and Fisher's LSD pair-comparisons revealed highly significant differences among the varieties in all traits. Correlation analyses showed negative associations between tuber yield and tuber traits (dry matter, DM; total soluble solids, TSS, EC and OP). Positive associations were found between tuber DM and TSS, EC and OP. There was no positive association between early maturation or yielding capacity and tolerance to salinity. Vivaldi, a high-yielding variety and Almera, a low-yielding variety were found significantly less susceptible to salinity than Mondial, a late-maturing and high-yielding variety, and Charlotte, an early-maturing and low-yielding variety. The significant differences in the response to salinity stress indicated genotypic variation in the response to salinity and support the potential of breeding for tolerance to salinity in potatoes. When seed tubers of the three irrigation treatments were grown with fresh water irrigation during the following season, there were no significant differences in plant growth or tuber yields from the three seed sources in most varieties indicating the possibility of using saline water for the production of potato seed tubers. © 2012 Elsevier B.V.

Dinu L.-D.,Agriculture and Agri Food Canada | Dinu L.-D.,University of Bucharest | Bach S.,Agriculture and Agri Food Canada
Applied and Environmental Microbiology | Year: 2011

Escherichia coli O157:H7 continues to be an important human pathogen and has been increasingly linked to food-borne illness associated with fresh produce, particularly leafy greens. The aim of this work was to investigate the fate of E. coli O157:H7 on the phyllosphere of lettuce under low temperature and to evaluate the potential hazard of viable but nonculturable (VBNC) cells induced under such stressful conditions. First, we studied the survival of six bacterial strains following prolonged storage in water at low temperature (4°C) and selected two strains with different nonculturable responses for the construction of E. coli O157:H7 Tn7gfp transformants in order to quantitatively assess the occurrence of human pathogens on the plant surface. Under a suboptimal growth temperature (16°C), both E. coli O157:H7 strains maintained culturability on lettuce leaves, but under more stressful conditions (8°C), the bacterial populations evolved toward the VBNC state. The strain-dependent nonculturable response was more evident in the experiments with different inoculum doses (10 9 and 10 6 E. coli O157:H7 bacteria per g of leaf) when strain BRMSID 188 lost culturability after 15 days and strain ATCC 43895 lost culturability within 7 days, regardless of the inoculum dose. However, the number of cells entering the VBNC state in high-cell-density inoculum (approximately 55%) was lower than in low-cell-density inoculum (approximately 70%). We recorded the presence of verotoxin for 3 days in samples that contained a VBNC population of 4 to 5 log 10 cells but did not detect culturable cells. These findings indicate that E. coli O157:H7 VBNC cells are induced on lettuce plants, and this may have implications regarding food safety. © 2011, American Society for Microbiology.

Rezvani E.,University of Natural Resources and Life Sciences, Vienna | Schleining G.,University of Natural Resources and Life Sciences, Vienna | Taherian A.R.,Agriculture and Agri Food Canada
LWT - Food Science and Technology | Year: 2012

Rheological properties, opacity, specific gravity, zeta potential, surface tension, particle size, and physical stability of orange oil-in-water beverage emulsions as a function of water phase and oil phase concentrations were investigated. Emulsions were formed by addition of oil phase (19.02-29.87. g/100. g) into the hydrated arabic gum (6.78-12.71. g/100. g) and inclusion of tragacanth gum (0.09-0.34. g/100. g). The specific gravity of oil phase was adjusted using a constant combination of weighting agent (ester gum) and orange oil. Response surface methodology (RSM) was used to evaluate the effect of independent variables (arabic gum:water, tragacanth:water and orange oil:water) on properties of prepared emulsions. The results showed that the two unstable emulsions, relatively, carry less electrical charges (-32.3. mV and -33. mV), have higher surface tensions (47.2. mN/m and 47.2. mN/m) and larger particle size (0.82 μm and 0.71 μm). The emulsion with apparent viscosity (at shear rate 0.1/s) of 32.26. mPa. s and particle size of 0.54 μm was more stable compared to the emulsion with apparent viscosity (at shear rate 0.1/s) of 400.67. mPa. s and particle size of 0.82 μm. Since the later emulsion also carried less electrical charges, it was suggested that electrostatic stabilization was dominant over steric stabilization. It was also noticed that the level of oil phase and arabic gum has the most significant effect on all response variables which prove that the concentration of these two components play a key role on formulation of beverage emulsion. © 2012.

Van Hezewijk B.H.,Agriculture and Agri Food Canada | Van Hezewijk B.H.,Natural Resources Canada | Bourchier R.S.,Agriculture and Agri Food Canada
Biological Control | Year: 2012

The root weevil . Cyphocleonus achates (Fahr.), and the seed-head weevil, . Larinus minutus Gyll. were introduced into North America as part of a classical biological control program against spotted (. Centaurea stoebe L. ssp. . micranthos (Gugler) Hayek) and diffuse knapweed (. Centaurea diffusa Lamarck). The impact of . C. achates alone, or in combination with . L. minutus, has not been assessed on diffuse knapweed. In a field study, densities of . C. achates were initially manipulated to measure its impact on the density, size, shape, and reproductive potential of diffuse knapweed. Subsequently . L. minutus was released at a constant rate across all experimental treatments to determine how attack by this species was affected by previous impacts of . C. achates. . C. achates reduced plant density by 58%, height by 29%, seed-head diameter by 4.6% as well as the number of seed heads per plant through its effect on plant height. Rosettes attacked by . C. achates also produced more flowering stems than unattacked plants and these plants produced fewer seed heads than unattacked plants after accounting for plant size. The reductions in seed-head size had a small negative effect on attack rates by . L. minutus but this was generally balanced by a positive effect of reduced seed-head numbers on . L. minutus attack rates. After accounting for direct impacts of root herbivory, attack rates by . L. minutus were still significantly lower in . C. achates plots. We conclude that the negative effects of . C. achates on diffuse knapweed outweigh the potential negative interactions with . L. minutus and that the two species will likely have additive effects when released in combination at diffuse knapweed sites. © 2012.

King R.R.,Agriculture and Agri Food Canada | Calhoun L.A.,University of New Brunswick
Phytochemistry | Year: 2010

1H NMR analysis established that a potential suberin intermediate isolated from potato common scab lesions contained three O-methyl groups, a phenylcoumaran-type linkage and a conjugated trans double bond. Mass spectral data determined its molecular formula as indicative of a dehydrotrimer structure formed from three feruloyltyramine units. 1H and 13C NMR correlation studies supported the structure as that of a grossamide unit (3) linked through its double bond to the feruloyl phenolic of a third feruloyltyramine group. Identification of the feruloyltyramine trimer (4) expands the number of cross-linked intermediates potentially involved in the suberization process and highlights the presence of a second type of inter-unit linkage available for synthesis of the poly-phenolic domains. © 2010 Elsevier Ltd. All rights reserved.

Yan W.,Agriculture and Agri Food Canada | Pageau D.,Agriculture and Agri Food Canada | Fregeau-Reid J.,Agriculture and Agri Food Canada | Durand J.,Semi Can Inc
Crop Science | Year: 2011

The success of a plant breeding program depends on many factors; one crucial factor is the selection of suitable breeding and testing locations. A test location must be discriminating so that genetic differences among genotypes can be easily observed, it must be representative of the target environments so that selected genotypes have the desired adaptation, and its representation of the target environment should also be repeatable so that genotypes selected in 1 yr will have superior performance in future years. Using the yield data of 2006 through 2010 Quebec Oat Registration and Recommendation Trials as an example, we presented a method to visualize the representativeness and repeatability of test locations based on a genotype main effect plus genotype × environment interaction (GGE) biplot. The repeatability of a test location could also be quantified by mean genetic correlations between years within the location. Based on representativeness and repeatability, four categories of test locations were classified and their usefulness in plant breeding discussed. © Crop Science Society of America.

Silim S.N.,Agriculture and Agri Food Canada | Ryan N.,Agriculture and Agri Food Canada | Kubien D.S.,University of New Brunswick
Photosynthesis Research | Year: 2010

To examine the role of acclimation versus adaptation on the temperature responses of CO2 assimilation, we measured dark respiration (Rn) and the CO2 response of net photosynthesis (A) in Populus balsamifera collected from warm and cool habitats and grown at warm and cool temperatures. Rn and the rate of photosynthetic electron transport (J) are significantly higher in plants grown at 19 versus 27°C; Rn is not affected by the native thermal habitat. By contrast, both the maximum capacity of rubisco (Vcmax) and A are relatively insensitive to growth temperature, but both parameters are slightly higher in plants from cool habitats. A is limited by rubisco capacity from 17-37°C regardless of growth temperature, and there is little evidence for an electron-transport limitation. Stomatal conductance (gs) is higher in warm-grown plants, but declines with increasing measurement temperature from 17 to 37°C, regardless of growth temperature. The mesophyll conductance (gm) is relatively temperature insensitive below 25°C, but gm declines at 37°C in cool-grown plants. Plants acclimated to cool temperatures have increased Rn/A, but this response does not differ between warm- and cool-adapted populations. Primary carbon metabolism clearly acclimates to growth temperature in P. balsamifera, but the ecotypic differences in A suggest that global warming scenarios might affect populations at the northern and southern edges of the boreal forest in different ways. © 2010 Springer Science+Business Media B.V.

Silversides F.G.,Agriculture and Agri Food Canada | Purdy P.H.,U.S. Department of Agriculture | Blackburn H.D.,U.S. Department of Agriculture
British Poultry Science | Year: 2012

1. There have been substantial losses of chicken lines kept for research in recent years and the objective of this research was to critically review alternative methods of preserving genetic resources.2. The costs of programmes using living populations, semen cryopreservation and reconstitution, and ovary and semen cryopreservation and reconstitution were evaluated over 20 years using biological parameters of cryopreservation and population reconstitution that were derived from the literature.3. Keeping live populations was most cost effective for periods of up to three years, but keeping live populations is increasingly difficult to justify with longer periods and any research population that will not be used within five years should be cryoconserved and in situ maintenance discontinued.4. The rapid reconstitution possible using ovaries and semen would allow the inclusion of cryopreserved material in a short-term research project with the cost of recovery included in the budget. The low cost of cryoconservation suggests that all avian material should be conserved and reconstituted when needed for research. © 2012 Copyright Taylor and Francis Group, LLC.

Druzhinina I.S.,Vienna University of Technology | Kubicek C.P.,Vienna University of Technology | Komo-Zelazowska M.,Vienna University of Technology | Mulaw T.B.,Vienna University of Technology | Bissett J.,Agriculture and Agri Food Canada
BMC Evolutionary Biology | Year: 2010

Background. The mitosporic fungus Trichoderma harzianum (Hypocrea, Ascomycota, Hypocreales, Hypocreaceae) is an ubiquitous species in the environment with some strains commercially exploited for the biological control of plant pathogenic fungi. Although T. harzianum is asexual (or anamorphic), its sexual stage (or teleomorph) has been described as Hypocrea lixii. Since recombination would be an important issue for the efficacy of an agent of the biological control in the field, we investigated the phylogenetic structure of the species. Results. Using DNA sequence data from three unlinked loci for each of 93 strains collected worldwide, we detected a complex speciation process revealing overlapping reproductively isolated biological species, recent agamospecies and numerous relict lineages with unresolved phylogenetic positions. Genealogical concordance and recombination analyses confirm the existence of two genetically isolated agamospecies including T. harzianum sensu stricto and two hypothetical holomorphic species related to but different from H. lixii. The exact phylogenetic position of the majority of strains was not resolved and therefore attributed to a diverse network of recombining strains conventionally called 'pseudoharzianum matrix'. Since H. lixii and T. harzianum are evidently genetically isolated, the anamorph - teleomorph combination comprising H. lixii/T. harzianum in one holomorph must be rejected in favor of two separate species. Conclusions. Our data illustrate a complex speciation within H. lixii - T. harzianum species group, which is based on coexistence and interaction of organisms with different evolutionary histories and on the absence of strict genetic borders between them. © 2010 Druzhinina et al; licensee BioMed Central Ltd.

Lee J.,U.S. Department of Agriculture | Dossett M.,Agriculture and Agri Food Canada | Finn C.E.,U.S. Department of Agriculture
Journal of Functional Foods | Year: 2013

The interest in black raspberry products has been increasing due to its flavor and potential health benefits. While black raspberries grown in North America are Rubus occidentalis, there has been some confusion regarding the identity of black raspberry grown in Korea (known as bokbunja; Rubus coreanus). As such, there is a need to define the anthocyanin profile of R. coreanus fruit collected from a verified source. We analyzed three genotypes of bokbunja fruit for anthocyanin profiles. While each varied in its anthocyanin proportions and total concentration, bokbunja fruit contained three anthocyanins: cyanidin-3-glucoside, cyanidin-3-rutinoside, and pelargonidin-3-glucoside, and lacked the xylose containing glycosides characteristic of R. occidentalis: cyanidin-3-sambubioside, and cyanidin-3-xylosylrutinoside. Due to mix-ups of bokbunja identity, research claiming to be conducted on bokbunja fruit requires confirmation that the fruit was sourced from a correctly identified plant. The distinct anthocyanin profiles between the two species can be used to confirm plant identity. © 2013.

Fageria M.S.,University of New Brunswick | Fageria M.S.,Agriculture and Agri Food Canada | Rajora O.P.,University of New Brunswick
Tree Genetics and Genomes | Year: 2014

Forest harvesting and renewal practices using clearcut harvesting followed by artificial and natural regeneration (NR) may impact genetic diversity in subsequent forest tree populations. Plantations (PL) and phenotypic selections may exhibit lower genetic diversity than natural old growth (OG) and naturally-regenerated young populations because they may have a narrow genetic base. We used ten (six EST and four genomic) microsatellite loci, to reassess genetic impacts of silvicultural practices in white spruce (Picea glauca), previously assessed by using 51 RAPD markers by Rajora (1999). Allelic diversity at the genomic microsatellite loci was about three times higher than at the EST-derived microsatellite loci. Although the trends for microsatellite genetic diversity among different stands types were similar to that observed for RAPD markers, with natural OG stands showing the highest and tree improvement selections the lowest allelic and genotypic genetic diversity, no significant differences were observed for microsatellite genetic diversity among OG, young NR, PL and open-pollinated progeny of first-generation phenotypic selections (SEL). The inbreeding levels and genetic differentiation among populations within OG, NR and PL were also similar. However, phenotypic selections had somewhat different genetic constitution as they showed the highest genetic distances with OG, NR and SEL. On the other hand, the lowest genetic distances were observed between the OG and NR stands, which also had similar levels of genetic diversity. Our study suggests no significant negative impacts of harvesting and alternative reforestation practices on microsatellite genetic diversity in white spruce and calls for using more than one marker type in assessing the genetic impacts of silvicultural practices in forest trees. © 2013 Springer-Verlag Berlin Heidelberg.

Mutanen M.,University of Oulu | Hausmann A.,Zoologische Staatssammlung Munich | Hebert P.D.N.,University of Guelph | Landry J.-F.,Agriculture and Agri Food Canada | And 2 more authors.
PLoS ONE | Year: 2012

Many cold adapted species occur in both montane settings and in the subarctic. Their disjunct distributions create taxonomic complexity because there is no standardized method to establish whether their allopatric populations represent single or different species. This study employs DNA barcoding to gain new perspectives on the levels and patterns of sequence divergence among populations of 122 arctic-alpine species of Lepidoptera from the Alps, Fennoscandia and North America. It reveals intraspecific variability in the barcode region ranging from 0.00-10.08%. Eleven supposedly different species pairs or groups show close genetic similarity, suggesting possible synonymy in many cases. However, a total of 33 species show evidence of cryptic diversity as evidenced by the presence of lineages with over 2% maximum barcode divergence in Europe, in North America or between the two continents. Our study also reveals cases where taxonomic names have been used inconsistently between regions and exposes misidentifications. Overall, DNA barcodes have great potential to both increase taxonomic resolution and to make decisions concerning the taxonomic status of allopatric populations more objective. © 2012 Mutanen et al.

Chung H.-J.,Agriculture and Agri Food Canada | Chung H.-J.,Korea University | Liu Q.,Agriculture and Agri Food Canada | Lee L.,Potato Research Academy | Wei D.,East China University of Science and Technology
Food Hydrocolloids | Year: 2011

The in vitro digestibility and molecular and crystalline structures of rice starches (Long-grain, Arborio, Calrose, and Glutinous) differing in amylose content were investigated and the relationship between the structure and in vitro digestibility of starch was studied. Long-grain showed the highest amylose content (27.2%), whereas Glutinous showed the lowest amylose content (4.2%). Long-grain had the highest average amylopectin branch chain length (18.8) and proportion (8.7%) of long branch chains (DP≥37), and the lowest proportion (26.9%) of short branch chains (DP 6-12). Among the non-waxy rice starches (Long-grain, Arborio, and Calrose), Calrose had the lowest average chain length (17.7) and the lowest proportion (7.1%) of long branch chains (DP≥37). The relative crystallinity of rice starch followed the order: Glutinous (33.5%)>Calrose (31.4%)>Arborio (31.0%)>Long-grain (29.9%). Long-grain had the highest gelatinization temperature and the lowest gelatinization temperature range, whereas Glutinous showed the highest gelatinization temperature range and gelatinization enthalpy. Arborio had the highest melting enthalpy for amylose-lipid complex among the tested rice starches. Pasting temperature, setback, and final viscosity increased with increasing amylose content, whereas the peak viscosity and breakdown showed negative correlations with amylose content. The rapidly digestible starch (RDS) content of the tested rice starches followed the order: Glutinous (71.4%)>Calrose (52.2%)>Arborio (48.4%)>Long-grain (39.4%). Contrary to this, the slowly digestible starch (SDS) and resistant starch (RS) contents showed an opposite trend compared to RDS. Digestibility (RDS, SDS, and RS) of the rice starches was significantly correlated (p≤0.05) with amylose content, proportions of DP 6-12 and DP 13-24, relative crystallinity, intensity ratio (of 1047cm-1 to 1022cm-1 from Fourier transform infrared spectroscopy), swelling factor, amylose leaching, onset temperature of gelatinization, gelatinization temperature range, gelatinization enthalpy, pasting temperature, peak viscosity, breakdown, setback, and final viscosity. © 2010.

Bartlett C.R.,University of Delaware | Hamilton K.G.A.,Agriculture and Agri Food Canada
Zootaxa | Year: 2011

The new genus Aethodelphax gen. nov. is described to include one new species, Aethodelphax prairianus sp. nov. and 7 species transferred from Delphacodes: Aethodelphax aetocephalus (Beamer, 1948), comb. nov., A. alatus (Beamer, 1948), comb. nov., A. caninus (Beamer, 1947), comb. nov., A. concavus (Beamer, 1948), comb. nov., A. megadontus (Beamer, 1951), comb. nov., A. paraparvulus (Beamer, 1948), comb. nov., and A. sagittatus (Beamer, 1947), comb. nov. A diagnosis for all species, illustrations and an identification key is provided. All species are found in the midwestern and southeastern states of the U.S., except A. caninus which is recorded from Arizona and New Mexico, and are all associated with native grasslands. © 2011 Magnolia Press.

Regnault-Roger C.,University of Pau and Pays de l'Adour | Vincent C.,Agriculture and Agri Food Canada | Arnason J.T.,University of Ottawa
Annual Review of Entomology | Year: 2012

In recent years, the use of essential oils (EOs) derived from aromatic plants as low-risk insecticides has increased considerably owing to their popularity with organic growers and environmentally conscious consumers. EOs are easily produced by steam distillation of plant material and contain many volatile, low-molecular-weight terpenes and phenolics. The major plant families from which EOs are extracted include Myrtaceae, Lauraceae, Lamiaceae, and Asteraceae. EOs have repellent, insecticidal, and growth-reducing effects on a variety of insects. They have been used effectively to control preharvest and postharvest phytophagous insects and as insect repellents for biting flies and for home and garden insects. The compounds exert their activities on insects through neurotoxic effects involving several mechanisms, notably through GABA, octopamine synapses, and the inhibition of acetylcholinesterase. With a few exceptions, their mammalian toxicity is low and environmental persistence is short. Registration has been the main bottleneck in putting new products on the market, but more EOs have been approved for use in the United States than elsewhere owing to reduced-risk processes for these materials. © 2012 by Annual Reviews. All rights reserved.

Wei T.,Agriculture and Agri Food Canada | Wei T.,University of Western Ontario | Wei T.,Fujian Agriculture and forestry University | Zhang C.,Agriculture and Agri Food Canada | And 6 more authors.
PLoS Pathogens | Year: 2013

All positive-strand RNA viruses induce the biogenesis of cytoplasmic membrane-bound virus factories for viral genome multiplication. We have previously demonstrated that upon plant potyvirus infection, the potyviral 6K2 integral membrane protein induces the formation of ER-derived replication vesicles that subsequently target chloroplasts for robust genome replication. Here, we report that following the trafficking of the Turnip mosaic potyvirus (TuMV) 6K2 vesicles to chloroplasts, 6K2 vesicles accumulate at the chloroplasts to form chloroplast-bound elongated tubular structures followed by chloroplast aggregation. A functional actomyosin motility system is required for this process. As vesicle trafficking and fusion in planta are facilitated by a superfamily of proteins known as SNAREs (soluble N-ethylmaleimide-sensitive-factor attachment protein receptors), we screened ER-localized SNARES or SNARE-like proteins for their possible involvement in TuMV infection. We identified Syp71 and Vap27-1 that colocalize with the chloroplast-bound 6K2 complex. Knockdown of their expression using a Tobacco rattle virus (TRV)-based virus-induced gene silencing vector showed that Syp71 but not Vap27-1 is essential for TuMV infection. In Syp71-downregulated plant cells, the formation of 6K2-induced chloroplast-bound elongated tubular structures and chloroplast aggregates is inhibited and virus accumulation is significantly reduced, but the trafficking of the 6K2 vesicles from the ER to chloroplast is not affected. Taken together, these data suggest that Syp71 is a host factor essential for successful virus infection by mediating the fusion of the virus-induced vesicles with chloroplasts during TuMV infection. © 2013 Wei et al.

Boye J.,Food and Agriculture Organization of the United Nations | Boye J.,Agriculture and Agri Food Canada | Wijesinha-Bettoni R.,Food and Agriculture Organization of the United Nations | Burlingame B.,Food and Agriculture Organization of the United Nations
British Journal of Nutrition | Year: 2012

In 1989 the Joint FAO/WHO Expert Consultation on Protein Quality Evaluation recommended the use of the Protein Digestibility Corrected Amino Acid Score (PDCAAS) method for evaluating protein quality. In calculating PDCAAS, the limiting amino acid score (i.e., ratio of first limiting amino acid in a gram of target food to that in a reference protein or requirement) is multiplied by protein digestibility. The PDCAAS method has now been in use for 20 years. Research emerging during this time has provided useful data on various aspects of protein quality evaluation that has made a review of the current methods used in assessing protein quality necessary. This paper provides an overview of the use of the PDCAAS method as compared to other methods and addresses some of the key challenges that remain in regards to protein quality evaluation. Furthermore, specific factors influencing protein quality including the effects of processing conditions and preparation methods are presented. Protein quality evaluation methods and recommended protein intakes currently used in different countries vis-à-vis the WHO/FAO/UNU standards are further provided. As foods are frequently consumed in complement with other foods, the significance of the PDCAAS of single protein sources may not be evident, thus, protein quality of some key food groups and challenges surrounding the calculation of the amino acid score for dietary protein mixtures are further discussed. As results from new research emerge, recommendations may need to be updated or revised to maintain relevance of methods used in calculating protein quality. © 2012 The Authors.

Klima C.L.,Agriculture and Agri Food Canada | Klima C.L.,University of Western Ontario | Zaheer R.,Agriculture and Agri Food Canada | Cook S.R.,Agriculture and Agri Food Canada | And 4 more authors.
Journal of Clinical Microbiology | Year: 2014

In this study, we determined the prevalence of bovine respiratory disease (BRD)-associated viral and bacterial pathogens in cattle and characterized the genetic profiles, antimicrobial susceptibilities, and nature of antimicrobial resistance determinants in collected bacteria. Nasopharyngeal swab and lung tissue samples from 68 BRD mortalities in Alberta, Canada (n = 42), Texas (n = 6), and Nebraska (n = 20) were screened using PCR for bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus, bovine herpesvirus 1, parainfluenza type 3 virus, Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni. Excepting bovine herpesvirus 1, all agents were detected. M. haemolytica (91%) and BVDV (69%) were the most prevalent, with cooccurrence in 63% of the cattle. Isolates of M. haemolytica (n = 55), P. multocida (n = 8), and H. somni (n = 10) from lungs were also collected. Among M. haemolytica isolates, a clonal subpopulation (n = 8) was obtained from a Nebraskan feedlot. All three bacterial pathogens exhibited a high rate of antimicrobial resistance, with 45% exhibiting resistance to three or more antimicrobials. M. haemolytica (n = 18), P. multocida (n = 3), and H. somni (n = 3) from Texas and Nebraska possessed integrative conjugative elements (ICE) that conferred resistance for up to seven different antimicrobial classes. ICE were shown to be transferred via conjugation from P. multocida to Escherichia coli and from M. haemolytica and H. somni to P. multocida. ICE-mediated multidrug-resistant profiles of bacterial BRD pathogens could be a major detriment to many of the therapeutic antimicrobial strategies currently used to control BRD. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Zhang Y.,University of Manitoba | Rempel C.,Canola Council of Canada | Liu Q.,Agriculture and Agri Food Canada
Critical Reviews in Food Science and Nutrition | Year: 2014

Canola Council of Canada, Winnipeg, Manitoba, Canada The rising costs of nonrenewable feedstocks and environmental concerns with their industrial usage have encouraged the study and development of renewable products, including thermoplastic starch (TPS). Starch is an abundant, plant-based biodegradable material with interesting physicochemical characteristics that can be exploited, and this has received attention for development of TPS products. Starch exhibits usable thermoplastic properties when plasticizers, elevated temperatures, and shear are present. The choice of plasticizer has an effect on TPS, even when these have similar plasticization principles. Most TPS have glass transition temperature, Tg, in the range of approximately -75 to 10°C. Glassy transition of TPS is detected by differential scanning calorimeter (DSC) and thermodynamic analyzer (DMA), although DMA has been found to be more sensitive and effective. TPS has low tensile properties, typically below 6 MPa in tensile strength (TS). The addition of synthetic polymers, nanoclay, and fiber can improve TS and water-resistance ability. The moisture sorption behavior of TPS is described in GAB and BET models, from which monolayer moisture content and specific area are derived. Current studies on surface tension, gas permeability, crystallinity, and so on of the TPS are also reviewed. © 2014 Copyright Taylor and Francis Group, LLC.

Rock L.,Queen's University of Belfast | Ellert B.H.,Agriculture and Agri Food Canada | Mayer B.,University of Calgary
Soil Biology and Biochemistry | Year: 2011

Soils comprise a critical interface between the atmosphere, lithosphere, hydrosphere and biosphere, and play a major role in the cycling of nitrogen (N), an element crucial to plant growth. Isotope techniques constitute a powerful tool to study the origin and fate of N compounds (e.g. NO3 -) within the environment including soils. The objective of our study was to test the usefulness of the isotope composition of soil NO3 - extracted with 2 M KCl (soil NO3) as a tool to investigate the origin and fate of NO3 - in the environment. Specifically issues related to repeat extractions, crop type, length of fertilization, and soil depth were addressed. Soils from four contrasting agricultural management regimes were sampled. Within the relatively confined study area (4 ha), the isotopic compositions of soil NO3 differed markedly due to management treatments (up to 6 and 17‰ for δ15N and δ18O, respectively), but were repeatable among replicate plots (±1‰). Differences in both δ15N and δ18O values were observed between legume and non-legume treatments, as well as fertilized versus non-fertilized treatments, which were larger than the variability observed between replicate plots. Differences in the isotopic composition of extractable soil nitrate were not limited to the surface layer, but also occurred within deeper soil layers. This study indicates that the analysis of the natural abundance stable isotope composition of soil NO3 may provide a promising additional tool for tracing the origin and fate of NO3 - in the soil zone. © 2011 Elsevier Ltd.

Huang T.-S.,Agriculture and Agri Food Canada | Huang T.-S.,University of Western Ontario | Wei T.,Agriculture and Agri Food Canada | Wei T.,University of Western Ontario | And 3 more authors.
Plant Physiology | Year: 2010

The viral genome-linked protein, VPg, of potyviruses is a multifunctional protein involved in viral genome translation and replication. Previous studies have shown that both eukaryotic translation initiation factor 4E (eIF4E) and eIF4G or their respective isoforms from the eIF4F complex, which modulates the initiation of protein translation, selectively interact with VPg and are required for potyvirus infection. Here, we report the identification of two DEAD-box RNA helicase-like proteins, PpDDXL and AtRH8 from peach (Prunus persica) and Arabidopsis (Arabidopsis thaliana), respectively, both interacting with VPg. We show that AtRH8 is dispensable for plant growth and development but necessary for potyvirus infection. In potyvirus-infected Nicotiana benthamiana leaf tissues, AtRH8 colocalizes with the chloroplast-bound virus accumulation vesicles, suggesting a possible role of AtRH8 in viral genome translation and replication. Deletion analyses of AtRH8 have identified the VPg-binding region. Comparison of this region and the corresponding region of PpDDXL suggests that they are highly conserved and share the same secondary structure. Moreover, overexpression of the VPg-binding region from either AtRH8 or PpDDXL suppresses potyvirus accumulation in infected N. benthamiana leaf tissues. Taken together, these data demonstrate that AtRH8, interacting with VPg, is a host factor required for the potyvirus infection process and that both AtRH8 and PpDDXL may be manipulated for the development of genetic resistance against potyvirus infections. © 2009 American Society of Plant Biologists.

Shalviri A.,University of Toronto | Liu Q.,Agriculture and Agri Food Canada | Abdekhodaie M.J.,University of Toronto | Abdekhodaie M.J.,Sharif University of Technology | Wu X.Y.,University of Toronto
Carbohydrate Polymers | Year: 2010

This work was intended to develop a new cross-linked gelatinized starch-xanthan gum hydrogel system, to characterize the properties of the new material, and to explore its potential applications in controlled drug delivery. Cross-linked starch-xanthan gum polymers were synthesized with varying levels of xanthan gum and sodium trimetaphosphate (STMP). The reaction of starch-xanthan gum polymers with STMP was examined using solid 31P NMR spectroscopy and FTIR. Morphology of the films made from the new polymers was studied by scanning electron microscopy. The swelling properties and the network parameters such as gel mesh size of the films were investigated. The permeation of solutes with various molecular weights and charges across the films was determined. 31P NMR and FTIR spectra showed that both starch and xanthan gum were reacted with STMP. The swelling ratio of the films was higher at higher STMP and xanthan gum levels. The gel mesh size increased with increasing swelling ratio varying from 2.84 to 6.74 nm. Permeability of anionic drugs across the polymeric films was significantly lower than their neutral form due mainly to the electrostatic repulsion between the negatively charged drugs and the polymer. The results suggest that the new cross-linked starch-xanthan gum hydrogels can be potentially used as a film-forming material in controlled release formulations. © 2009 Elsevier Ltd. All rights reserved.

Anzar M.,Agriculture and Agri Food Canada | Kroetsch T.,Semex Alliance | Boswall L.,Agriculture and Agri Food Canada
Animal Reproduction Science | Year: 2011

In the Canadian Animal Genetic Resource Program, bull semen is donated in frozen or fresh (diluted) states. This study was designed to assess the cryopreservation of diluted bull semen shipped at 4. °C overnight, and to determine the post-thaw quality of shipped semen using different straw volumes and freezing rates. Semen was collected from four breeding bulls (three ejaculates per bull). Semen was diluted in Tris-citric acid-egg yolk-glycerol (TEYG) extender, cooled to 4. °C and frozen as per routine (control semen). After cooling to 4. °C, a part of semen was removed and shipped overnight to the research laboratory via express courier (shipped semen). Semen was packaged in 0.25 or 0.5. ml straws and frozen in a programmable freezer using three freezing rates, i.e., -10, -25 or -40. °C/min. Control semen was also shipped to the research laboratory. Post-thaw sperm motility characteristics were assessed using CASA, and post-thaw sperm plasma membrane, mitochondrial membrane potential and normal acrosomes were assessed using flow cytometry. Post-thaw sperm quality was greater in shipped semen as compared to control (P<. 0.001). The shipped semen packaged in 0.25. ml straws had better post-thaw sperm quality than in 0.5. ml straws (P<. 0.001). Freezing rate had no effect on post-thaw sperm quality. In conclusion, bull semen can be shipped overnight for subsequent cryopreservation and gene banking. Overnight shipping of semen was found advantageous for bull semen cryopreservation. Semen packaging in 0.25. ml straws yielded better post-thaw quality than 0.5. ml straws. © 2011.

Vicente-Serrano S.M.,CSIC - Pyrenean Institute of Ecology | Zouber A.,Agriculture and Agri Food Canada | Lasanta T.,CSIC - Pyrenean Institute of Ecology | Pueyo Y.,CSIC - Pyrenean Institute of Ecology
Ecological Monographs | Year: 2012

Semiarid Mediterranean regions are highly susceptible to desertification processes. This study investigated the influence of increasing climate aridity in explaining the decline in vegetation cover in highly vulnerable gypsum semiarid shrublands of the Mediterranean region. For this purpose, we have used time series of percent cover of vegetation obtained from remote sensing imagery (Landsat satellites). We found a dominant trend toward decreased vegetation cover, mainly in summer and in areas affected by the most severe water stress conditions (low precipitation, higher evapotranspiration rates, and sunexposed slopes). We show that past human management and current climate trends interact with local environmental conditions to determine the occurrence of vegetation degradation processes. The results suggest that degradation could be a consequence of the past overexploitation that has characterized this area (and many others in the Mediterranean region), but increased aridity, mainly related to global warming, may be triggering and/or accelerating the degradation processes. The observed pattern may be an early warning of processes potentially affecting more areas of the Mediterranean, according to the most up-todate climate change models for the 21st century. © 2012 by the Ecological Society of America.

Jia D.,Fujian Agriculture and forestry University | Mao Q.,Fujian Agriculture and forestry University | Chen H.,Fujian Agriculture and forestry University | Wang A.,Agriculture and Agri Food Canada | And 4 more authors.
Journal of Virology | Year: 2014

The plant reoviruses, plant rhabdoviruses, tospoviruses, and tenuiviruses are transmitted by insect vectors in a persistent propagative manner. These viruses induce the formation of viral inclusions to facilitate viral propagation in insect vectors. The intestines of insect vectors are formed by epithelial cells that lie on the noncellular basal lamina surrounded by visceral muscle tissue. Here, we demonstrate that a recently identified plant reovirus, southern rice black-streaked dwarf virus (SRBSDV), exploits virus-containing tubules composed of virus-encoded nonstructural protein P7-1 to directly cross the basal lamina from the initially infected epithelium toward visceral muscle tissues in the intestine of its vector, the white-backed planthopper (Sogatella furcifera). Furthermore, such tubules spread along visceral muscle tissues through a direct interaction of P7-1 and actin. The destruction of tubule assembly by RNA interference with synthesized double-stranded RNA targeting the P7-1 gene inhibited viral spread in the insect vector in vitro and in vivo. All these results show for the first time that a virus employs virus-induced tubule as a vehicle for viral spread from the initially infected midgut epithelium through the basal lamina, facilitating the rapid dissemination of virus from the intestine of the insect vector. © 2014, American Society for Microbiology.

Marti R.,Agriculture and Agri Food Canada | Scott A.,Agriculture and Agri Food Canada | Tien Y.-C.,Agriculture and Agri Food Canada | Murray R.,Agriculture and Agri Food Canada | And 3 more authors.
Applied and Environmental Microbiology | Year: 2013

Consumption of vegetables represents a route of direct human exposure to bacteria found in soil. The present study evaluated the complement of bacteria resistant to various antibiotics on vegetables often eaten raw (tomato, cucumber, pepper, carrot, radish, lettuce) and how this might vary with growth in soil fertilized inorganically or with dairy or swine manure. Vegetables were sown into field plots immediately following fertilization and harvested when of marketable quality. Vegetable and soil samples were evaluated for viable antibiotic-resistant bacteria by plate count on Chromocult medium supplemented with antibiotics at clinical breakpoint concentrations. DNA was extracted from soil and vegetables and evaluated by PCR for the presence of 46 gene targets associated with plasmid incompatibility groups, integrons, or antibiotic resistance genes. Soil receiving manure was enriched in antibiotic-resistant bacteria and various antibiotic resistance determinants. There was no coherent corresponding increase in the abundance of antibiotic-resistant bacteria enumerated from any vegetable grown in manure-fertilized soil. Numerous antibiotic resistance determinants were detected in DNA extracted from vegetables grown in unmanured soil. A smaller number of determinants were additionally detected on vegetables grown only in manured and not in unmanured soil. Overall, consumption of raw vegetables represents a route of human exposure to antibiotic-resistant bacteria and resistance determinants naturally present in soil. However, the detection of some determinants on vegetables grown only in freshly manured soil reinforces the advisability of pretreating manure through composting or other stabilization processes or mandating offset times between manuring and harvesting vegetables for human consumption. © 2013, American Society for Microbiology.

Vandenbygaart A.J.,Agriculture and Agri Food Canada | Kroetsch D.,Agriculture and Agri Food Canada | Gregorich E.G.,Agriculture and Agri Food Canada | Lobb D.,362 Ellis Building
Global Change Biology | Year: 2012

Erosion influences the lateral and vertical distribution of soil in agricultural landscapes. A better understanding of the effects of erosion and redistribution on soil organic carbon (C) within croplands would improve our knowledge of how management practices may affect global C dynamics. In this study, the vertical and lateral distribution of soil organic C was characterized to evaluate the amounts and timescales of soil organic C movement, deposition and burial over the last 50 years in different agroecosystems across Canada. There was strong evidence that a substantial portion of eroded sediment and soil organic C was deposited as colluvium close to its source area, thereby burying the original topsoil. The deepest aggraded profile was in a potato field and contained over 70 cm of deposited soil indicating an accumulation rate of 152 Mg ha yr -1; aggraded profiles in other sites had soil deposition rates of 40-90 Mg ha -1 yr -1. The largest stock of soil organic C was 463 Mg ha -1 (to 60 cm depth) and soil C deposition ranged from about 2 to 4 Mg ha -1 yr -1 across all sites. A distinct feature observed in the aggraded profiles at every site was the presence of a large increase in soil organic C concentration near the bottom of the A horizon; the concentration of this C was greater than that at the soil surface. Compared to aggraded profiles, the SOC concentration in eroded profiles did not differ with depth, suggesting that dynamic replacement of soil organic C had occurred in eroded soils. A large amount of soil organic C is buried in depositional areas of Canadian croplands; mineralization of this stock of C appears to have been constrained since burial, but it may be vulnerable to future loss by management practices, land use change and a warming climate. © Her Majesty the Queen in Right of Canada 2011.

Chen H.Y.H.,Lakehead University | Shrestha B.M.,Lakehead University | Shrestha B.M.,Agriculture and Agri Food Canada
Soil Biology and Biochemistry | Year: 2012

Soil organic carbon (SOC) in mineral soil accounts for a large portion of total ecosystem carbon (C) in boreal forests. We evaluated the effects of stand age and disturbance origin on SOC, soil aggregate stability, and aggregate-associated SOC in the boreal forests of Ontario, Canada. Mineral soils at 0-15 cm depth were sampled in 27 stands of six post-fire age classes (2- to 203-year-old) and three post-clearcut age classes (2- to 29-year-old), each with three replications. In post-fire stands, the SOC pool increased from 2- and 10-year-old to 29-, 85- and 140-year-old, and then decreased in 203-year-old stands. Aggregate-associated SOC showed a similar trend. Abundance of water stable aggregates (>0.25 mm in diameter) was the highest in 2-year-old stands. Compared with the same-aged post-fire stands, the SOC pool and aggregate-associated SOC were higher, and aggregate stability was lower in 2- and 10-year-old post-clearcut stands. But the differences in SOC pool, aggregate-associated SOC, and aggregate stability between the two stand origins diminished or became less dramatic in 29-year-old stands. Our results indicate that aggregate stability is more dependent on thermal modification of SOC by fire than on aggregate-associated SOC. Our results also show higher SOC pool and aggregate-associated SOC but lower aggregate stability in post-clearcut than post-fire stands shortly after disturbance; however, differences between the two stand origins diminish when stands become older. © 2012 Elsevier Ltd.

Lee H.-S.,Gyeongnam Agricultural Research and Extension Services | Gillespie D.R.,Agriculture and Agri Food Canada
Experimental and Applied Acarology | Year: 2011

Development time, reproduction, survival and sex ratio were determined for the omnivorous mite Amblyseius swirskii at nine constant temperatures (13, 15, 18, 20, 25, 30, 32, 34 and 36°C) on pepper leaf disks with cattail, Typha latifolia, pollen for food. These data were used to derive life table parameters at these constant temperatures. No development was observed at 13°C. The lower development threshold, based on the fit to the linear portion of the development curve, was 11.3°C. The upper development threshold was 37.4 ± 1.12°C, and the optimum temperature was calculated to be 31.5°C. Average lifetime fecundity ranged from a low of 1.3 ± 0.24 eggs/female at 15°C to a high of 16.1 ± 0.34 eggs/female at 25°C, and rm was greatest at 32°C. Non-linear regression of the relationship between temperature and rm produced an estimate of 15.49 ± 0.905°C for the lower threshold for population growth and 36.99 ± 0.816°C for the upper threshold for population growth, and an optimum temperature of 30.1°C. These values suggest that A. swiskii populations should grow quickly in response to food availability (pollen or prey) between 20 and 32°C, but that, especially below 20°C, population growth could be slow and impacts on prey populations should be monitored carefully. © 2010 Her Majesty the Queen in Right of Canada.

Joensuu J.J.,VTT Technical Research Center of Finland | Joensuu J.J.,Agriculture and Agri Food Canada | Conley A.J.,Agriculture and Agri Food Canada | Conley A.J.,University of Western Ontario | And 4 more authors.
Plant Physiology | Year: 2010

Insufficient accumulation levels of recombinant proteins in plants and the lack of efficient purification methods for recovering these valuable proteins have hindered the development of plant biotechnology applications. Hydrophobins are small and surface-active proteins derived from filamentous fungi that can be easily purified by a surfactant-based aqueous two-phase system. In this study, the hydrophobin HFBI sequence from Trichoderma reesei was fused to green fluorescent protein (GFP) and transiently expressed in Nicotiana benthamiana plants by Agrobacterium tumefaciens infiltration. The HFBI fusion significantly enhanced the accumulation of GFP, with the concentration of the fusion protein reaching 51% of total soluble protein, while also delaying necrosis of the infiltrated leaves. Furthermore, the endoplasmic reticulum-targeted GFP-HFBI fusion induced the formation of large novel protein bodies. A simple and scalable surfactant-based aqueous two-phase system was optimized to recover the HFBI fusion proteins from leaf extracts. The single-step phase separation was able to selectively recover up to 91% of the GFP-HFBI up to concentrations of 10 mg mL-1. HFBI fusions increased the expression levels of plant-made recombinant proteins while also providing a simple means for their subsequent purification. This hydrophobin fusion technology, when combined with the speed and posttranslational modification capabilities of plants, enhances the value of transient plant-based expression systems. © 2009 American Society of Plant Biologists.

Chung H.-J.,Korea University | Liu Q.,Agriculture and Agri Food Canada
International Journal of Biological Macromolecules | Year: 2010

In this study, potato and bean starches were treated by gamma-irradiation up to 50. kGy. Molecular structure and physicochemical properties of irradiated potato and bean starches were investigated. Microscopic observation under scanning electron microscope (SEM) and polarized microscope showed that some of potato and bean starch granules were destroyed by gamma-irradiation and the breakage was much greater at a higher dose (50. kGy). Carboxyl content and amylose leaching increased, whereas the swelling factor and apparent amylose content decreased after irradiation in both potato and bean starches. The proportions of short (DP 6-12) and long (DP ≥ 37) amylopectin chains as well as average chain length increased with increasing irradiation dose. However, the proportion of DP 13-24 decreased by irradiation. The relative crystallinity, the degree of granule surface order, and gelatinization enthalpy decreased with an increase in irradiation dose. The extent of decrease in potato starch was greater than that in bean starch. The exothermic peak around 90-110°C was observed in DSC thermogram when the potato starch was irradiated at 50. kGy. The pasting viscosity significantly decreased with an increase in irradiation dose. The proportion of slowly digestible starch (SDS) decreased and resistant starch (RS) content increased by irradiation in both potato and bean starches. However, the rapidly digestible starch (RDS) of potato starch increased with increasing irradiation dose, whereas the bean starch showed the opposite trend to potato starch in RDS content. © 2010 .

McKellar R.C.,Agriculture and Agri Food Canada | Leblanc D.I.,University of Moncton | Lu J.,Food Research and Development Center | Delaquis P.,Agriculture and Agri Food Canada
Foodborne Pathogens and Disease | Year: 2012

The temperature of packaged lettuce was recorded throughout a retail supply chain in Canada during the various stages of storage and shipping from the processor to retail. Temperatures were monitored in 27 cases of lettuce destined for three stores in three replicate trials conducted during the winter. A dynamic model that predicts the effect of temperature on the growth or die-off of Escherichia coli O157:H7 in packaged fresh-cut lettuce was applied to simulate the behavior of E. coli O157:H7 in the system. Simulations were carried out using distributions to account for variation in the temperature parameter and the die-off coefficient of the dynamic growth/death model. The results indicate that there was a predicted overall mean decline in cell numbers of 0.983 log cfu g -1 and that the extent of cell death was proportional to the total time spent in the cold chain. Slight growth was predicted in a few instances when the dynamic temperature was above the permissive temperature of 5°C. These results suggest that generally there would be little or no growth of E. coli O157:H7 in product maintained at the proper temperature in the chain. Moreover, the predicted decline in cell numbers at refrigeration temperatures suggests that storage at 5°C or below prior to consumption would reduce populations of the pathogen in fresh-cut lettuce. © 2012, Mary Ann Liebert, Inc.

Cote J.,INRS Institute Armand Frappier | Caillet S.,INRS Institute Armand Frappier | Doyon G.,Agriculture and Agri Food Canada | Sylvain J.,Atoka Cranberries Inc. | Lacroix M.,INRS Institute Armand Frappier
Critical Reviews in Food Science and Nutrition | Year: 2010

Cranberries are healthy fruit that contribute color, flavor, nutritional value, and functionality. They are one of only three fruits native to America. Over the past decade, public interest for the North American cranberry (Vaccinium macrocarpon) has been rising with reports of their potential health benefits linked to the numerous phytochemicals present in the fruit the anthocyanins, the flavonols, the flavan-3-ols, the proanthocyanidins, and the phenolic acid derivatives. The presence of these phytochemicals appears to be responsible for the cranberry property of preventing many diseases and infections, including cardiovascular diseases, various cancers, and infections involving the urinary tract, dental health, and Helicobacter pylori-induced stomach ulcers and cancers. Recent years have seen important breakthroughs in our understanding of the mechanisms through which these compounds exert their beneficial biological effects, yet these remain to be scientifically substantiated. In this paper these characteristics, as well as the antioxidant, radical scavenging, antibacterial, antimutagen, and anticarcinogen properties of cranberry major bioactive compounds are explained. © Taylor and Francis Group, LLC.

Cote J.,INRS Institute Armand Frappier | Caillet S.,INRS Institute Armand Frappier | Doyon G.,Agriculture and Agri Food Canada | Sylvain J.-F.,Atoka Cranberries Inc. | Lacroix M.,INRS Institute Armand Frappier
Critical Reviews in Food Science and Nutrition | Year: 2010

There is a growing public interest for the North American cranberry (Vaccinium macrocarpon) as a functional food because of the potential health benefits linked to phytochemical compounds present in the fruit-the anthocyanin pigments, responsible for its brilliant red color, and other secondary plant metabolites (flavonols, flavan-3-ols, proanthocyanidins, and phenolic acid derivatives). Isolation of these phenolic compounds and flavonoids from a sample matrix is a prerequisite to any comprehensive analysis scheme. By far the most widely employed analytical technique for the characterization of these compounds has been high-performance liquid chromatography(HPLC) coupled with ultraviolet-visible(UV/Vis) and mass spectrometer(MS) detection. This review covers the cranberry major bioactive compounds, the extraction and purification methods, and the analytical conditions for HPLC used to characterize them. Extraction, chromatographic separation and detection strategies, analyte determinations, and applications in HPLC are discussed and the information regarding methods of specific cranberry analyte analyses has been summarized in tabular form to provide a means of rapid access to information pertinent to the reader. © Taylor and Francis Group, LLC.

Yan L.,Jiangxi Science and Technology Normal University | Chang P.R.,Agriculture and Agri Food Canada | Zheng P.,Jiangxi Science and Technology Normal University | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2012

The hydrophobicity of carbon nanotubes (CNTs) limits their extensive application. The hydrophilicity and biocompatibility of CNTs can be improved by modifying them with biopolymers. As a natural biopolymer, guar gum (GG) was covalently grafted on the surfaces of multiwall carbon nanotube (MWCNT) to obtain GG-MWCNT composite. Then iron oxide nanoparticles were synthesized on the GG-MWCNT to prepare the magnetic GG-MWCNT-Fe 3O 4. The obtained nanocomposites were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, ultraviolet-visible (UV-vis) spectroscopy and X-ray diffraction. GG-MWCNT was composed of about 21.6 wt% GG components, which enhanced the dispersion of GG-MWCNT in aqueous solution and also acted as a template for growth of iron oxide nanoparticles. GG-MWCNT-Fe 3O 4 exhibited superparamagnetic with a saturation magnetization (13.3 emu g -1), and good adsorption on neutral red and methylene blue. GG-MWCNT-Fe 3O 4 could be easily separated from the aqueous solution in a magnetic field. © 2011 Elsevier Ltd. All rights reserved.

Chang P.R.,Agriculture and Agri Food Canada | Qian D.,Tianjin University | Anderson D.P.,Agriculture and Agri Food Canada | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2012

Porous starch (PS) was prepared by replacing ice crystals in frozen starch gel with ethanol using a solvent exchange technique. It was then modified by succinic anhydride (SA) in a solvent/catalyst-free medium, and the obtained SA-modified PSs (SAPSs) were characterized. The degrees of substitution (DSs) of SA could be controlled by changing the SA/starch molar ratios. A high linear relationship (>0.99) between the DS and molar ratio was found. The effect of different DSs (0-1.90) on the pore size, apparent density, moisture adsorption, oil adsorption capacity and methylene blue (MB) adsorption of SAPSs was investigated. Apparent density, oil adsorption capacity and methylene blue (MB) adsorption of SAPSs increased gradually with the increasing DSs. SAPSs exhibited higher moisture content at equilibrium than PS. In addition, the adsorption of MB by SAPSs could be described well by a pseudo second-order model. © 2011 Elsevier Ltd. All rights reserved.

Chang P.R.,Agriculture and Agri Food Canada | Wu D.,Tianjin University | Anderson D.P.,Agriculture and Agri Food Canada | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2012

Sodium rectorite clay (REC) was attached to cationic guar gum (CGG) using a cationic-exchange reaction to obtain CGG modified-REC (CREC). It was found that CGG appeared on the surface of REC's layered structure and represented about 30.1% wt. in CREC. REC and CREC were, respectively, used as fillers in a plasticized starch (PS) matrix to prepare PS/REC and PS/CREC composites using the casting process. Rapid Visco Analyser and scanning electron microscopy revealed that an interaction existed between the REC (or CREC) filler and the matrix. Both REC and CREC had obvious reinforcing effects on the matrix. Compared to the neat matrix, REC or CREC improved the thermal stability of the composites. By increasing the filler content from 0 to 10 wt%, water vapor permeability (WVP) values of PS/REC composites obviously decreased, while WVP values of PS/CREC composites decreased slightly. © 2012 Published by Elsevier Ltd. All rights reserved.

Gupta U.C.,Agriculture and Agri Food Canada | Gupta S.C.,Loma Linda University
Pedosphere | Year: 2014

Mineral nutrients are fundamentally metals and other inorganic compounds. The life cycle of these mineral nutrients begins in soil, their primary source. Soil provides minerals to plants and through the plants the minerals go to animals and humans; animal products are also the source of mineral nutrients for humans. Plant foods contain almost all of the mineral nutrients established as essential for human nutrition. They provide much of our skeletal structure, e.g., bones and teeth. They are critical to countless body processes by serving as essential co-factors for a number of enzymes. Humans can not utilize most foods without critical minerals and enzymes responsible for digestion and absorption. Though mineral nutrients are essential nutrients, the body requires them in small, precise amounts. We require them in the form found in crops and they can be classified into three different categories: major, secondary, and micro or trace minerals. This classification is based upon their requirement rather than on their relative importance. Major minerals such as potassium (K) and phosphorus (P) are required in amounts of up to 10 g d-1. The daily requirement of secondary and micro minerals ranges from 400 to 1 500 mg d-1 and 45 μg d-1 to 11 mg d-1, respectively. To protect humans from mineral nutrient deficiencies, the key is to consume a variety of foods in modest quantities, such as different whole grains, low fat dairy, and different meats, vegetables and fruits. For insurance purposes, a supplement containing various mineral nutrients can be taken daily. © 2014 Soil Science Society of China.

Ma T.,Tianjin University | Chang P.R.,Agriculture and Agri Food Canada | Zheng P.,Jiangxi Science and Technology Normal University | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2013

The graphite was oxidized to prepare graphene oxide (GO), and GO was reduced by glucose to obtain reduced graphene oxide (RGO) sheet. There were abundant and residual oxygen-containing groups on GO and RGO, respectively. Compared to graphite, the GO and RGO sheets appeared flat and transparent, and the aqueous suspensions followed the Lambert-Beer's law well. The composites were also fabricated by using GO and RGO as the filler in plasticized-starch (PS) matrix. Because of more oxygen-containing groups, GO could form the stronger interaction with PS matrix than RGO. And GO/PS composites exhibited better tensile strength, elongation at break and moisture barrier than RGO/PS composites, but lower thermal stability. GO/PS composites could protect against UV light, while the conductivities of RGO/PS composites could reach 1.07 × 10-4, 6.92 × 10-4 and 0.01 S/cm, respectively stored at RH50, 75 and 100%. Crown Copyright © 2013 Published by Elsevier Ltd. All rights reserved.

Yu J.,Tianjin University | Chang P.R.,Agriculture and Agri Food Canada | Chang P.R.,University of Saskatchewan | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2010

Dialdehyde starch (DAS) is prepared by periodate oxidation of starch, and DAS with different aldehyde contents is plasticized by glycerol to obtain thermoplastic DAS (TPDAS). DAS is characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The crystalline starch is destroyed and oxidized to form amorphous DAS, while amorphous starch inside of starch granules is degraded. As a result, DAS containing 93.05% aldehyde content formes a ring shape. Compared to thermoplastic native starch, the re-crystallization of DAS can not take place in TPDAS during the storage period, because periodate oxidation has destroyed the crystallization of starch. With the increasing of aldehyde contents of DAS, the tensile strength and the resistance of both moisture absorption and water vapor permeability of TPDAS are improved. It is ascribed to the cross-linking of aldehyde groups in TPDAS. © 2009 Elsevier Ltd. All rights reserved.

Wu D.,Tianjin University | Chang P.R.,Agriculture and Agri Food Canada | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2011

The Zn-Al layered double hydroxide (LDH) was fabricated using carboxymethyl-cellulose sodium (CMC) as the stabilizer in aqueous solution, and then used as the filler to prepare LDH-CMC/glycerol plasticized-starch (GPS) nanocomposites in the casting process. Transmission electron microscopy exhibited the platelets of LDH-CMC with a lateral size of 30-60 nm and the thickness of 5-10 nm. X-ray diffraction showed that the presence of CMC decreased the thickness of LDH. The chemical formulas of LDH was [Zn 0.64·Al0.36·(OH)2]Cl 0.36·nH2O, and the content of CMC was about 37.5 wt%. LDH-CMC possessed the good stability in water because of hydrophilic CMC components and the smaller size of each LDH stack. A low loading of LDH-CMC (below 6 wt%) could obviously improve mechanical properties and water vapor barrier of the nanocomposites, because LDH-CMC could form the good interaction with GPS matrix.© 2011 Elsevier Ltd All rights reserved.

Chang P.R.,Agriculture and Agri Food Canada | Yu J.,Tianjin University | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2011

In this communication, a facile and green method is introduced for the preparation of porous starch (PS), citric acid-modified PS (CAPS) and porous ZnO. PS was created by replacing ice crystals in frozen starch gel with selected solvent using a solvent exchange technique. The porosity of PS was greatly affected by the ethanol/water volume ratios. PS was further modified with citric acid (CA) in order to preserve or maintain its porous state, especially upon contact with aqueous solution. CAPS was subsequently used as a structure-directing agent to prepare ZnO with a porous network structure. The thus obtained PS, CAPS and porous ZnO may find their niche in applications such as adsorbent, structure-directing agents for porous metal oxides or as sensors. © 2010 Elsevier Ltd. All rights reserved.

Xie Y.,Tianjin University | Chang P.R.,Agriculture and Agri Food Canada | Wang S.,Tianjin University | Yu J.,Tianjin University | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2011

A traditional Chinese medicine, Dioscorea opposita Thunb. is rich in starch, which was isolated and used to prepare the plasticized starch (PS). And PS was composited with halloysite nanotube (HNT) by the casting process. Amylose content of native starch was about 24.5%, and the granules were in the size of about 20 μm. The starch showed the typical B-type with relative crystallinity of 26.9%. According to the characterization of the composites with scanning electron microscope, mechanical tensile testing, rapid visco-analyser, thermogravimetric analysis and water vapor permeability, HNT could obviously improve the pasting viscosity, mechanical properties, thermal stability and water vapor barrier of the composites. When HNT contents varied from 0 to 9 wt%, the tensile strength increased from 3.9 to 9.7 MPa, and the water vapor permeability decreased from 8.48 × 10-10 to 6.61 × 10-10 g m-1 s-1 Pa-1 at RH 75% and from 14.54 × 10-10 to 11.7 × 10-10 g m -1 s-1 Pa-1 at RH 100%. © 2010 Elsevier Ltd.

Qian D.,Tianjin University | Chang P.R.,Agriculture and Agri Food Canada | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2011

Porous starch (PS) was created by replacing ice crystals in frozen starch gel with ethanol using a solvent exchange technique. In the single freezing process, the porous structures of PSs were controlled by changing the starch paste concentrations. With the increasing of concentrations from 5 to 20%, pore size, moisture adsorption, oil adsorption capacity and methylene blue (MB) adsorption of PSs decreased greatly, while the apparent density increased from 0.093 to 0.689 g/cm3. In the dual freezing process, the porous structures of citric acid-modified PS (CAPS0) were full of starch pastes with different concentrations (1.5, 2.5 and 3.5%), and then frozen again. Compared to CAPS0, PSs from the dual freezing process exhibited larger apparent density and MB adsorption, but lower moisture adsorption and oil adsorption capacity. And the starch paste concentrations (1.5-3.5%) had few effects on the properties of PSs in the second freezing process. Copyright © 2011 Published by Elsevier Ltd. All rights reserved.

Chang P.R.,Agriculture and Agri Food Canada | Chang P.R.,University of Saskatchewan | Yu J.,Tianjin University | Ma X.,Tianjin University | Anderson D.P.,Agriculture and Agri Food Canada
Carbohydrate Polymers | Year: 2011

In this study, superparamagnetic Fe3O4 nanoparticles were individually prepared with one of three polysaccharides as stabilizer, i.e. soluble starch, carboxymethyl cellulose sodium (CMC) and agar. Since polysaccharides present the dynamic supramolecular associations facilitated by inter- and intra-molecular hydrogen bonding, they can act as templates for the growth of nanosized Fe3O4. The resultant polysaccharide-Fe3O4 were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) analysis, transmission electron microscopy (TEM), X-ray diffraction (XRD) and magnetic properties. TEM revealed that Fe3O4 was encapsulated by polysaccharides. The particle size of starch-Fe3O4 (SF) was obviously smaller than those from CMC-Fe3O4 (CF) and agar-Fe3O4 (AF). TG analysis was used to calculate the Fe3O4 contents of SF, CF and AF - 62.7, 47.8 and 57.4%, respectively. The saturation magnetization (20.43 emu/g) of AF was much lower than that of SF (36.16 emu/g) and CF (35.75 emu/g). The polysaccharide-Fe 3O4 exhibited an extremely small hysteresis loop and low coercivity. © 2010 Elsevier Ltd. All rights reserved.

Hagel J.M.,University of Calgary | Krizevski R.,Newe Ya'ar Research Center | Marsolais F.,Agriculture and Agri Food Canada | Lewinsohn E.,Newe Ya'ar Research Center | Facchini P.J.,University of Calgary
Trends in Plant Science | Year: 2012

Amphetamine analogs are produced by plants in the genus Ephedra and by Catha edulis, and include the widely used decongestants and appetite suppressants pseudoephedrine and ephedrine. A combination of yeast (Candida utilis or Saccharomyces cerevisiae) fermentation and subsequent chemical modification is used for the commercial production of these compounds. The availability of certain plant biosynthetic genes would facilitate the engineering of yeast strains capable of de novo pseudoephedrine and ephedrine biosynthesis. Chemical synthesis has yielded amphetamine analogs with myriad functional group substitutions and diverse pharmacological properties. The isolation of enzymes with the serendipitous capacity to accept novel substrates could allow the production of substituted amphetamines in synthetic biosystems. Here, we review the biology, biochemistry and biotechnological potential of amphetamine analogs in plants. © 2012 Elsevier Ltd.

Betts A.K.,U.S. National Center for Atmospheric Research | Desjardins R.,Agriculture and Agri Food Canada | Worth D.,Agriculture and Agri Food Canada
Journal of Geophysical Research: Atmospheres | Year: 2013

This analysis uses 40 years of hourly observations of temperature (T), relative humidity (RH), and opaque cloud cover from 14 climate stations across the Canadian Prairies to analyze the diurnal cycle climate, represented by the mean T and RH and their diurnal ranges. From April to October, when incoming shortwave radiation dominates over longwave cooling, maximum temperature and the diurnal ranges of T and RH increase with decreasing opaque cloud cover, while minimum temperature is almost independent of cloud. During the winter period, both maximum and minimum temperatures fall with decreasing cloud, as longwave cooling dominates over the net shortwave flux, which is reduced by the high solar zenith angle and surface reflection by snow. We relate the daily mean opaque cloud cover to the longwave and shortwave cloud forcing and the effective cloud albedo, using multiyear measurements of downward shortwave and longwave fluxes, and longwave fluxes under clear skies from historical weather reanalysis. We provide quadratic fits to compute effective cloud albedo and net longwave fluxes from opaque cloud cover. During the warm season, the daytime rise of temperature is related to the net radiation, and the nighttime fall is related to the net longwave cooling. The diurnal range of T, RH, and all the net radiative fluxes have a quasi-linear dependence on the effective cloud albedo. This gives a seasonal climate perspective on the coupled land-surface system of T, RH, and cloud cover over the Canadian Prairies, and the winter transitions in snowy climates. © 2013. Her Majesty the Queen in Right of Canada. American Geophysical Union.

Chang P.R.,Agriculture and Agri Food Canada | Zheng P.,Jiangxi Science and Technology Normal University | Liu B.,Tianjin University | Anderson D.P.,Agriculture and Agri Food Canada | And 2 more authors.
Journal of Hazardous Materials | Year: 2011

Soluble starch-functionalized multiwall carbon nanotube composites (MWCNT-starch) were prepared to improve the hydrophilicity and biocompatibility of MWCNTs. Characterization of the MWCNT-starch by Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM) and thermogravimetric analysis (TG), showed that the starch component (about 14.3. wt%) was covalently grafted onto the surface of MWCNT. MWCNT-starch-iron oxide composites, intended for use as adsorbents for the removal of dyes from aqueous solutions, were prepared by synthesizing iron oxide nanoparticles at the surface of MWCNT-starch. Starch acts as a template for growth of iron oxide nanoparticles which are uniformly dispersed on the surface of the MWCNT-starch. MWCNT-starch-iron oxide exhibits superparamagnetic properties with a saturation magnetization (23.15. emu/g) and better adsorption for anionic methyl orange (MO) and cationic methylene blue (MB) dyes than MWCNT-iron oxide. © 2011 Elsevier B.V.

Zheng P.,Jiangxi Science and Technology Normal University | Chang P.R.,Agriculture and Agri Food Canada | Ma X.,Tianjin University
Industrial and Engineering Chemistry Research | Year: 2013

The mineral clay rectorite (REC) was used successfully to prepare ultralight gels by the simple process of freezing the aqueous gel precursor, exchanging the solvent (ice-ethanol), and performing ethanol drying rather than employing supercritical drying technology. The light bulk density of the rectorite (REC) gel was only 18.95 mg/cm3. Three-dimensional networks in REC gels were composed of REC sheets. Cationic guar gum could intercalate into the REC layers or attach on the REC surface and consolidate the REC gel networks. This novel porous REC gel material contained many macropores and a few mesopores. The REC gel could adsorb ethanol and soybean oil as much as 5.62 and 15.8 times the weight of the gel, respectively. In addition, the adsorptions of methylene blue dye and stearic acid (phase-change material) could reach 95.24 mg/g and 39.7 g/g, respectively. REC gels thus have potential for applications in wastewater treatment and thermal energy storage. © 2013 American Chemical Society.

Betts A.K.,U.S. National Center for Atmospheric Research | Desjardins R.,Agriculture and Agri Food Canada | Worth D.,Agriculture and Agri Food Canada | Cerkowniak D.,Agriculture and Agri Food Canada
Journal of Geophysical Research: Atmospheres | Year: 2013

This paper uses hourly observations from 1953 to 2011 of temperature, relative humidity, and opaque cloud cover from 14 climate stations across the Canadian Prairies to analyze the impact of agricultural land use change on the diurnal cycle climate, represented by the mean temperature and relative humidity and their diurnal ranges. We show the difference between the years 1953-1991 and 1992-2011. The land use changes have been largest in Saskatchewan where 15-20% of the land area has been converted in the past four decades from summer fallow (where the land was left bare for 1 year) to annual cropping. During the growing season from 20 May to 28 August, relative humidity has increased by about 7%. During the first 2 months, 20 May to 19 July, maximum temperatures and the diurnal range of temperature have fallen by 1.2°C and 0.6°C, respectively, cloud cover has increased by about 4%, reducing surface net radiation by 6 W m-2, and precipitation has increased. We use the dry-downs after precipitation to separate the impact of cloud cover and show the coupling between evapotranspiration and relative humidity. We estimate, using reanalysis data from ERA-Interim, that increased transpiration from the larger area of cropland has reduced the surface Bowen ratio by 0.14-0.2. For the month on either side of the growing season, cloud cover has fallen slightly; maximum temperatures have increased, increasing the diurnal temperature range and the diurnal range of humidity. Key Points Increased annual cropping has cooled and moistened the summer climate More transpiration has increased precipitation and lowered cloud base Changing seasonal diurnal temperature and humidity ranges ©2013. Her Majesty the Queen in Right of Canada. American Geophysical Union. Reproduced with permission of the Minister of Agriculture and Agri-Food Canada.

Chang P.R.,Agriculture and Agri Food Canada | Jian R.,Tianjin University | Zheng P.,Jiangxi Science and Technology Normal University | Yu J.,Tianjin University | Ma X.,Tianjin University
Carbohydrate Polymers | Year: 2010

In this paper, cellulose nanoparticles (CN) were coagulated from a NaOH/urea/H2O solution of microcrystalline cellulose (MC) using an ethanol/HCl aqueous solution as the precipitant. CN ranged in size from about 50 to 100 nm. Compared to MC, CN formed a new crystalline lattice of cellulose II. The glycerol plasticized-wheat starch (GPS)/CN nanocomposites were prepared using CN as filler in GPS matrix by a casting process. At a low loading level, CN was dispersed evenly in the GPS matrix. The tensile strength increased from 3.15 to 10.98 MPa when CN content went from 0 to 5 wt.%. CN may increase the thermal stability of GPS/CN composites. Moreover, water vapor permeability decreased from 5.75 × 10-10 to 3.43 × 10-10 g m-1 s-1 Pa-1. The improvements in these properties may be attributed to the good interaction between CN filler and GPS matrix because of the similar polysaccharide structures of cellulose and starch. © 2009 Elsevier Ltd. All rights reserved.

McKellar R.C.,Agriculture and Agri Food Canada | Delaquis P.,Research Scientist
International Journal of Food Microbiology | Year: 2011

Escherichia coli O157:H7, an occasional contaminant of fresh produce, can present a serious health risk in minimally processed leafy green vegetables. A good predictive model is needed for Quantitative Risk Assessment (QRA) purposes, which adequately describes the growth or die-off of this pathogen under variable temperature conditions experienced during processing, storage and shipping. Literature data on behaviour of this pathogen on fresh-cut lettuce and spinach was taken from published graphs by digitization, published tables or from personal communications. A three-phase growth function was fitted to the data from 13 studies, and a square root model for growth rate (μ) as a function of temperature was derived: μ=(0.023*(Temperature-1.20)) 2. Variability in the published data was incorporated into the growth model by the use of weighted regression and the 95% prediction limits. A log-linear die-off function was fitted to the data from 13 studies, and the resulting rate constants were fitted to a shifted lognormal distribution (Mean: 0.013; Standard Deviation, 0.010; Shift, 0.001). The combined growth-death model successfully predicted pathogen behaviour under both isothermal and non-isothermal conditions when compared to new published data. By incorporating variability, the resulting model is an improvement over existing ones, and is suitable for QRA applications. © 2011.

Cheng J.,Tianjin University | Chang P.R.,Agriculture and Agri Food Canada | Zheng P.,Jiangxi Science and Technology Normal University | Ma X.,Tianjin University
Industrial and Engineering Chemistry Research | Year: 2014

β-Cyclodextrin (CD) grafted carbon nanotube (CNT) composites were prepared by the reduction of oxidized CNT with hydrazine hydrate in the presence of CD. The obtained reduced CNT-CD (RCNT-CD) was attached to iron oxide particles in preparation of magnetic RCNT-CD (M-RCNT-CD). These composites were characterized by Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetric analysis (TG). About 17 wt % CD was grafted onto RCNT, and about 23.5 wt % iron oxide particles were attached to the RCNT-CD. The kinetic adsorption fit the pseudo-second-order model, and the isotherm data followed the Langmuir model. The maximum adsorption capacity reached 196.5 mg/g for M-RCNT-CD, indicating that it is a good adsorbent for methylene blue. The positive free energy change (ΔG) and negative enthalpy change (ΔH) illustrated that the adsorption process was spontaneous and endothermic. M-RCNT-CD can be easily separated from solution in the magnetic field. © 2014 American Chemical Society.

Chang P.R.,Agriculture and Agri Food Canada | Chang P.R.,University of Saskatchewan | Jian R.,Tianjin University | Yu J.,Tianjin University | Ma X.,Tianjin University
Food Chemistry | Year: 2010

Chitosan nanoparticles (CNs), obtained by physical crosslinking between tripolyphosphate and protonised chitosan, were used as filler in a glycerol plasticised-starch (GPS) matrix to be used in food packaging. In GPS/CN composites, the chemical structures of the matrix and the filler are similar because they are both polysaccharides. The influences of the filler content on the morphology, viscosity, mechanical properties, dynamic mechanical properties, water vapour permeation and thermal degradation of GPS/CN composites were studied. It was shown that the obvious improved effect on the tensile strength, storage modulus, glass transition temperature, water vapour barrier and thermal stability could be attributed to the filler/matrix interactions, which occurred when CN was dispersed uniformly in the GPS matrix at low content. However, higher CN loads (8 wt.%) resulted in the aggregation of CN in the composites. © 2009 Elsevier Ltd. All rights reserved.

Sanborn P.,University of Northern British Columbia | Lamontagne L.,Agriculture and Agri Food Canada | Hendershot W.,McGill University
Canadian Journal of Soil Science | Year: 2011

Podzolic soils occupy 14.3% of the Canadian landmass, and occur in two widely separated areas, eastern Canada (northern Ontario, Quebec, Maritimes) and British Columbia, usually under coniferous forest and on non-calcareous parent materials. Broad climatic control of Podzol distribution and properties is evident at the national scale, with higher organic matter concentrations (Ferro-Humic Podzols) in wetter climates, in contrast to Humo-Ferric Podzols predominating in drier boreal forest regions. Humic Podzols are least abundant and are restricted to the wettest landscape positions. International and Canadian research suggests that a more diverse range of processes is involved in podzolization than was envisioned in the 1960s, and proposed mechanisms must account for observed patterns of organic matter distribution and a diverse array of inorganic amorphous constituents in profiles. Taxonomic concepts of Podzolic soils in the Canadian System of Soil Classification have remained consistent since the late 1970s, and the higher-level criteria defining the order and its great groups have proved to be meaningful in new applications, such as delineating soil carbon stocks across Canadian landscapes. Canadian contributions to pedological research on Podzols declined dramatically after 1990, coincident with shifting research priorities in soil science and diminished activity in soil survey.

Gunnaiah R.,McGill University | Kushalappa A.C.,McGill University | Duggavathi R.,McGill University | Fox S.,Agriculture and Agri Food Canada | Somers D.J.,Vineland Research and Innovation Center
PLoS ONE | Year: 2012

Background: Resistance in plants to pathogen attack can be qualitative or quantitative. For the latter, hundreds of quantitative trait loci (QTLs) have been identified, but the mechanisms of resistance are largely unknown. Integrated non-target metabolomics and proteomics, using high resolution hybrid mass spectrometry, were applied to identify the mechanisms of resistance governed by the fusarium head blight resistance locus, Fhb1, in the near isogenic lines derived from wheat genotype Nyubai. Findings: The metabolomic and proteomic profiles were compared between the near isogenic lines (NIL) with resistant and susceptible alleles of Fhb1 upon F. graminearum or mock-inoculation. The resistance-related metabolites and proteins identified were mapped to metabolic pathways. Metabolites of the shunt phenylpropanoid pathway such as hydroxycinnamic acid amides, phenolic glucosides and flavonoids were induced only in the resistant NIL, or induced at higher abundances in resistant than in susceptible NIL, following pathogen inoculation. The identities of these metabolites were confirmed, with fragmentation patterns, using the high resolution LC-LTQ-Orbitrap. Concurrently, the enzymes of phenylpropanoid biosynthesis such as cinnamyl alcohol dehydrogenase, caffeoyl-CoA O-methyltransferase, caffeic acid O-methyltransferase, flavonoid O-methyltransferase, agmatine coumaroyltransferase and peroxidase were also up-regulated. Increased cell wall thickening due to deposition of hydroxycinnamic acid amides and flavonoids was confirmed by histo-chemical localization of the metabolites using confocal microscopy. Conclusion: The present study demonstrates that the resistance in Fhb1 derived from the wheat genotype Nyubai is mainly associated with cell wall thickening due to deposition of hydroxycinnamic acid amides, phenolic glucosides and flavonoids, but not with the conversion of deoxynivalenol to less toxic deoxynivalenol 3-O-glucoside. © 2012 Gunnaiah et al.

Thang C.L.,McGill University | Boye J.I.,Agriculture and Agri Food Canada | Zhao X.,McGill University
Journal of Nutrition | Year: 2013

Probiotic supplementation and oral tolerance induction can reduce certain types of food allergy. The objectives of this study were to investigate the allergy-reducing effects of probiotics (VSL#3) and/or oral tolerance induction via low doses of an allergen supplementation in β-lactoglobulin (BLG)-sensitized mice. Three-week-old, male BALB/c mice were divided into 6 groups (n = 8/group): sham-sensitized negative control (CTL-), BLG-sensitized positive control (CTL+), oral tolerance-induced and BLG-sensitized group (OT), probiotic-supplemented OT group (OTP), probiotic-supplemented CTL2 (PRO), and probiotic-supplemented and BLG-sensitized (PROC) groups. Mice were i.p. sensitized with BLG and alum and then orally challenged with BLG. Immunological responses were assessed by monitoring hypersensitivity scores and measuring levels of BLG-specific serum Igs, total serum IgE and fecal IgA, and cytokines from serum and spleen lysates. Hypersensitivity scores were significantly lower in the PROC (2.00 ± 0.53), OT (0.75 ± 0.46), and OTP mice (1.00 6 0.53) than in the CTL+ mice (2.63 6 0.52) as were BLG-specific serum IgE concentrations (34.3 6 10, 0.442 ± 0.36, 3.54 ± 3.5, and 78.5 ± 8.7 μg/L for PROC, OT, OTP, and CTL+, respectively). Our results suggest that supplementation of VSL#3 suppressed the allergic reaction mainly through increased intestinal secretary IgA (sIgA) in PROC mice, and oral tolerance offered allergen-specific protective effects to BLG-induced allergy, probably through CD4+CD25+ regulatory T cellmediated active suppression. In OTP mice, probiotics did not induce a further reduction of hypersensitivity score compared with OT mice but may provide additional protection to unforeseen nonspecific challenges through increased intestinal sIgA. J. Nutr. 143: 136-141, 2013. © 2013 American Society for Nutrition.

Chen C.,McGill University | Whalen J.K.,McGill University | Guo X.,Agriculture and Agri Food Canada
Soil Biology and Biochemistry | Year: 2014

Nitrous oxide (N2O) is a greenhouse gas that is released from both nitrification and denitrification processes. Soil moisture content is a key controller of the biochemical pathways leading to N2O emission, causing a switch between nitrification and denitrification processes. Earthworms are reported to increase N2O emissions from soil under aerobic and anaerobic conditions, but how earthworm-induced N2O emissions are affected by soil drying and rewetting cycles is unknown. The objectives of this study were to (1) evaluate earthworm-induced N2O emissions from soils with aerobic, anaerobic, and fluctuating soil moisture conditions; and (2) determine the earthworm effects on soil denitrifiers responsible for N2O fluxes. Soils were kept in mesocosms (polyvinyl chloride plastic tubes, 10cm diameter, filled with soil to 15cm depth) at constant 33% water-filled pore space (WFPS), constant 97% WFPS or underwent three wetting-drying cycles (WD). Each soil moisture treatment had 2 earthworm treatments, including (1) a mixture of endogeic Aporrectodea turgida and anecic Lumbricus terrestris and (2) no earthworm treatment. These gave a total of 6 treatments in this study, with 5 replicates for each treatment. The N2O fluxes were quantified every one to three days, and the soil denitrifier activities were measured after 69 days, when the experiment ended. Soil moisture significantly affected N2O emissions and the WD treatment had the highest cumulative N2O emissions. Earthworms increased N2O emissions by 50% in the 33% WFPS treatment but decreased N2O emissions by 34% in the 97% WFPS treatment, probably due to more complete reduction of N2O to N2. Earthworms strongly reduced N2O emission rate in WD treatment, and they significantly reduced cumulative N2O emissions by 82%. Soil denitrification enzyme activity (DEA) increased significantly when earthworms were present. Abundance of 16S rRNA, nirS, and nosZ genes was affected significantly by the earthworm×soil moisture interaction, with the highest 16S rRNA and nosZ abundance in soil from the WD treatments. We conclude that the decrease in cumulative N2O emissions from soil at 97% WFPS and the WD treatment by earthworms was due to an alteration of the denitrifying bacterial community composition. © 2013 Elsevier Ltd.

Royaute R.,McGill University | Royaute R.,Agriculture and Agri Food Canada | Buddle C.M.,McGill University | Vincent C.,Agriculture and Agri Food Canada
Ethology | Year: 2014

Variations in environmental conditions can influence behavioral syndromes (correlated tendencies in behaviors), and understanding the factors that shape trait covariation is particularly relevant when species are challenged by environmental changes. We investigated how behavioral syndromes varied at extremes of a gradient of anthropogenic disturbance, using apple orchards with different histories of insecticidal applications as a model system. Eris militaris (Araneae: Salticidae) jumping spiders were sampled from an insecticide-free orchard and an insecticide-treated orchard from Southern Québec. Spiders were tested for activity, aggression, boldness, and voracity under standardized conditions. Behavioral syndrome structure was compared between the two populations using Bayesian multiresponse models and structural equation modeling. Syndrome structure differed significantly between the two populations. The insecticide-free population showed evidence of a syndrome involving all measured traits, while only aggression, boldness and voracity were correlated in the insecticide-treated population. The insecticide-free population showed negative correlations between active and voracious behavioral types vs. aggressive and bold types while the insecticide-treated population showed a negative correlation between aggression-boldness and voracity. This research is a first step in investigating the impact of anthropogenic disturbances on behavioral syndromes and demonstrates that behavioral syndromes may vary with respect to insecticidal applications. © 2013 Blackwell Verlag GmbH.

Huang H.,McGill University | Liu L.,McGill University | Ngadi M.O.,McGill University |