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Lado J.,CSIC - Institute of Agricultural Chemistry and Food Technology | Lado J.,Instituto Nacional Of Investigacion Agropecuaria Inia | Rodrigo M.J.,CSIC - Institute of Agricultural Chemistry and Food Technology | Cronje P.,Stellenbosch University | Zacarias L.,CSIC - Institute of Agricultural Chemistry and Food Technology
Postharvest Biology and Technology | Year: 2015

Grapefruit are among the more sensitive Citrus varieties likely to develop chilling injury (CI) symptoms during postharvest storage at low temperatures. Comparative observations of the incidence of CI in fruit of white Marsh (MSH) and red Star Ruby (SR) grapefruit during postharvest storage at 2. °C plus 7 days at 20. °C to simulate shelf-life revealed that (1) the former was consistently more sensitive to CI, developing cold damage uniformly throughout the whole rind surface, and (2) more strikingly, CI symptoms in fruit of SR grapefruit were restricted to the yellow areas of the rind and the red-colored zones were almost absent of cold damage. This tolerance to CI in red flavedo was associated with high carotenoid (×2) and lycopene (×14) contents, as compared with yellow-colored flavedo. Absence of chilling damage in red areas of SR grapefruit rind was confirmed by cellular ultrastructure observations, in which these epidermal cells were intact, with a well-defined structure and compact vacuoles filled with content. Cells of yellow-colored tissue developing CI, were collapsed, with a contracted vacuole and shrinking organelles. To explore whether the tolerance to CI in red areas of grapefruit rind was due to an elevated lycopene concentration, chemical and environmental stimulation of this carotenoid was performed in fruit of both grapefruit varieties. Application of the inhibitor of the lycopene cyclase activity, CPTA (2-(4-chlorophenylthio) triethylamine hydrochloride) induced red coloration, increased lycopene accumulation (×32) and significantly delayed development of CI symptoms in the rind the CI-sensitive MSH. Bagging of SR grapefruit enhanced a homogenous red coloration and substantially induced lycopene accumulation (×75). CI symptoms in bagged fruit were notably delayed and reduced, as compared with non-bagged yellow fruit, upon subsequent storage at 2. °C for up to 58 days and 7 days at 20. °C. Analysis of the expression of ethylene biosynthetic genes (ACS1, ACS2 and ACO) revealed a significant induction in chilling-damaged tissue of both varieties that was almost absent in red chilling-tolerant tissue. Similarly, accumulation of transcripts of the ethylene receptors ETR1 and ETR3 were also associated with chilling damage, but a cold factor appears to also mediate the expression of these genes. Taken together, our results indicate that high lycopene concentration appears to be responsible for the induction of tolerance to chilling in the red-colored areas of the flavedo of grapefruit during postharvest storage at low temperatures. © 2014 Elsevier B.V..


Bonnecarrere V.,Instituto Nacional Of Investigacion Agropecuaria Inia | Borsani O.,Laboratorio Of Bioquimica | Diaz P.,Laboratorio Of Bioquimica | Capdevielle F.,Instituto Nacional Of Investigacion Agropecuaria Inia | And 2 more authors.
Plant Science | Year: 2011

Two japonica rice genotypes, INIA Tacuarí and L2825CA, were analyzed for tolerance to low temperature during early vegetative growth. Effect on photosynthesis, energy dissipation, pigment content, xanthophyll-cycle pool conversion, hydrogen peroxide accumulation, oxidative damage and antioxidant enzyme activities were determined to better understand potential mechanisms for cold tolerance. Photoinhibition was measured using chlorophyll fluorescence and oxidative damage by lipid peroxidation and electrolyte leakage. Both genotypes were demonstrated to be cold tolerant which was consistent with their reduced levels of photoinhibition and oxidative damage compared with a cold-sensitive genotype during chilling stress. The strategy for cold tolerance differed between the two genotypes, and involved different mechanisms for disposal of excess energy. The presence of high lutein concentrations and the existence of active non-harmful energy dissipation processes through the xanthophyll cycle appeared to be responsible for chilling tolerance in INIA Tacuarí. On the other hand, increased cold tolerance of L2825CA relative to INIA Tacuarí was related to the higher constitutive superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11) and catalase (CAT, EC 1.11.1.6). © 2011 Elsevier Ireland Ltd.


Beyhaut E.,Instituto Nacional Of Investigacion Agropecuaria Inia | Larson D.L.,U.S. Geological Survey | Allan D.L.,University of Minnesota | Graham P.H.,University of Minnesota
Plant and Soil | Year: 2014

Background and aims: Prairie restoration aims to create self-sustaining, resilient prairies that ameliorate biodiversity loss and soil deterioration associated with conversion of native grasslands to agriculture. Legumes are a key component of the nitrogen-limited prairie ecosystem. Evidence suggests that lack of suitable rhizobia may explain legume absence from restored prairies. This study explores effects of novel alternative inoculant delivery methods on: (a) prairie legume establishment, (b) soil biological properties, and (c) inoculant strain ability to nodulate the host over time. Methods: Alternative inoculation methods for seven legume species were tested in a replicated field experiment. Legume establishment, microbial biomass carbon and nitrogen, and rhizobial inoculant strain recovery were measured over a 3-year period. Results: Legume species richness in the second growing season was enhanced by a soil-applied granular clay inoculant, while seed-applied powdered peat inoculation was generally ineffective. When Dalea rhizobia were recovered 3-year after planting, only 2 % from the seed-applied inoculation treatment identified with the inoculant strains, whereas this amount ranged from 53 to 100 % in the other inoculation treatments. Some legumes established unexpectedly effective symbioses with strains not originally intended for them. Conclusions: Results provide new insights on inoculation of native legumes, especially when a mix of seeds is involved and the restoration targets harsh environments. © 2013 Springer Science+Business Media Dordrecht.


Perez C.A.,University of Minnesota | Wingfield M.J.,University of Pretoria | Slippers B.,University of Pretoria | Altier N.A.,Instituto Nacional Of Investigacion Agropecuaria Inia | Blanchette R.A.,University of Minnesota
Fungal Diversity | Year: 2010

Species of the Botryosphaeriaceae are important pathogens causing cankers and die-back on many woody plants. In Uruguay, Neofusicoccum eucalyptorum, N. ribis and B. dothidea have previously been associated with stem cankers on plantation-grown Eucalyptus globulus. However, very little is known regarding the occurrence and species diversity of Botryosphaeriaceae in native Myrtaceae forests or what their relationship is to those species infecting Eucalyptus in plantations. The objectives of this study were to identify the Botryosphaeriaceae species present as endophytes or associated with cankers in both introduced and native tree hosts in Uruguay, and to test the pathogenicity of selected isolates obtained from native trees on Eucalyptus. Symptomatic and asymptomatic material was collected countrywide from Eucalyptus plantations and native Myrtaceae trees. Single spore cultures were identified based on conidial morphology and comparisons of DNA sequences of the ITS and EF1-α regions. Six Botryosphaeriaceae species were identified. Botryosphaeria dothidea, N. eucalyptorum and specimens residing in the N. parvum-N. ribis complex were isolated from both introduced Eucalyptus and native Myrtaceae trees, whereas Lasiodiplodia pseudotheobromae was found only on Myrcianthes pungens. Diplodia pseudoseriata sp. nov. and Spencermartinsia uruguayensis sp. nov. are novel species found only on native myrtaceous hosts. Pathogenicity tests showed that isolates obtained from native trees and identified as L. pseudotheobromae, N. eucalyptorum and the N. parvum-N.ribis complex are pathogenic to E. grandis. Interestingly, Lasiodiplodia pseudotheobromae has not previously been found on Eucalyptus in Uruguay and represents a potential threat to this host. © Kevin D. Hyde 2010.


Retta D.,University of Buenos Aires | Dellacassa E.,University of the Republic of Uruguay | Villamil J.,Instituto Nacional Of Investigacion Agropecuaria Inia | Suarez S.A.,National University of Rio Cuarto | Bandoni A.L.,University of Buenos Aires
Industrial Crops and Products | Year: 2012

Medicinal plants and their extracts are natural resources of compounds used for treatments in ethnomedicine and phytotherapy. They are also a source of natural products used in the development of new related compounds and drugs for conventional medicine. The increasing interest in use of herbal medicines requires a comprehensive assessment of research data in this field to help focus future efforts. Here we review the increasingly important role of Achyrocline satureioides (Lam.) DC (Asteraceae), marcela, which is used extensively in popular medicine. Like most medicinal plants, however, A. satureioides is generally not cultivated and most plants used commercially are harvested from ecologically and edaphically diverse natural habitats. We provide information on the current status of this promising medicinal and aromatic plant, and an overall view of its potential for production of material with more desirable physicochemical and phytochemical properties. © 2012 Elsevier B.V.


Perez E.,Instituto Nacional Of Investigacion Agropecuaria Inia | Blanco O.,Instituto Nacional Of Investigacion Agropecuaria Inia | Berreta C.,Planta de Jugo | Dol I.,University of the Republic of Uruguay | Lado J.,Instituto Nacional Of Investigacion Agropecuaria Inia
Postharvest Biology and Technology | Year: 2011

The extensive use of imazalil (IMZ) in Uruguayan citrus packinghouses to control Penicillium spp. favored the selection and proliferation of resistant isolates. With the aim of detecting Penicillium digitatum biotypes that are not controlled by commercial doses of IMZ, the IMZ concentration within amended potato dextrose agar (PDA) plates was adjusted to 1.0mgL -1 IMZ. This concentration allowed the detection of resistant isolates that were not controlled by commercial applications of 3.0gL -1 IMZ. These isolates were able to grow in fruit with IMZ residues of 0.92 and 3.08mgkg -1. Therefore, environmental monitoring of facilities where commercial dip applications containing 3.0gL -1 IMZ are employed, should be done with 1.0mgL -1 of IMZ in Petri dishes. We can conclude that use of IMZ in postharvest applications of 3.0gL -1 remains effective to control wild Uruguayan P. digitatum isolates but not for resistant ones. A survey of 26 P. digitatum isolates collected in Uruguay indicated IMZ resistant isolates occurred in packinghouses and not in citrus groves. © 2011 Elsevier B.V.


Self-feeding of supplements to livestock can be a useful practice among those producers limited on time and labor resources to handle daily supplementation of cattle. The objective of the study was to evaluate self-feeding of an energetic supplement on the performance of steers (326±23 kg) grazing high quality temperate pastures. Treatments were: 1) control group without supplementation, 2) hand-fed daily supplementation at 1% of body weight (BW), 3) restricted self-feeding supplementation at 1% BW loading the feeder once a week, 4) self-feeding supplementation ad-libitum. The ration used in self-feeding treatments contained 10% salt to limit food intake. Feed intake in self-feeding ad-libitum supplementation (6.7 kg/a/d) was greater than that registered in supplemented treatments at 1% BW either hand-fed (3.6 kg/a/d) or restricted self-feeding (3.7 kg/a/d). In this last treatment, the feeder was empty during 2 to 3 days per week to adjust feed intake at 1% BW. The final BW and average daily gain of supplemented animals (382±29 kg and 1.012±0.546 kg/a/d, respectively) were greater (p < 0.05) compared to those obtained in the control group (329±25 kg and 0.198±0.276 kg/a/d), without differences associated with the delivery method of the ration (p > 0.05). Conversion efficiency of the supplement, expressed as the amount of supplement (kg) required to gain 1 kg of live weight above the performance of the control group, tended to worsen in self-feeding treatments (5.2 and 6.9 kg restricted and ad-libitum, respectively) compared to the hand-fed daily supplementation (4.7 kg). Supplemented animals registered a greater rib eye area and fat (intramuscular and subcutaneous) than animals in the control group. Self-feeding supplementation is a useful strategy to cope with the high cost and/or lack of labor in livestock operations although supplement feed conversion can be negatively affected due to the high intake of ration and its associated salt.


Perez C.A.,University of the Republic of Uruguay | Wingfield M.J.,University of Pretoria | Altier N.,Instituto Nacional Of Investigacion Agropecuaria Inia | Blanchette R.A.,University of Minnesota
Fungal Biology | Year: 2013

Mycosphaerella species are well-known causal agents of leaf diseases on many economically and ecologically important plant species. In Uruguay, a relatively large number of Mycosphaerellaceae and Teratosphaeriaceae are found on Eucalyptus, but nothing is known of these fungi on native Myrtaceae. The aim of this study was to identify Mycosphaerellaceae and Teratosphaeriaceae species associated with leaf diseases on native Myrtaceae in Uruguay and to consider whether host jumps by the pathogen from introduced Eucalyptus to native Myrtaceae have occurred. Several native forests throughout the country were surveyed with special attention given to those located close to Eucalyptus plantations. Five species belonging to the Mycosphaerellaceae and Teratosphaeriaceae clades were found on native Myrtaceous trees and three of these had previously been reported on Eucalyptus in Uruguay. Those occurring both on Eucalyptus and native Myrtaceae included Pallidocercospora heimii, Pseudocercospora norchiensis, and Teratosphaeria aurantia. In addition, Mycosphaerella yunnanensis, a species known to occur on Eucalyptus but not previously recorded in Uruguay, was found on leaves of two native Myrtaceous hosts. Because most of these species occur on Eucalyptus in countries other than Uruguay, it appears that they were introduced in this country and have adapted to be able to infect native Myrtaceae. These apparent host jumps have the potential to result in serious disease problems and they should be carefully monitored. © 2012 The British Mycological Society.


Umpierrez-Failache M.,University of the Republic of Uruguay | Garmendia G.,University of the Republic of Uruguay | Pereyra S.,Instituto Nacional Of Investigacion Agropecuaria Inia | Rodriguez-Haralambides A.,University of the Republic of Uruguay | And 2 more authors.
International Journal of Food Microbiology | Year: 2013

Members of the Fusarium graminearum species complex (FGSC) are the primary cause of Fusarium head blight (FHB) of wheat, and frequently contaminate grain with trichothecene mycotoxins that pose a serious threat to food safety and animal health. The species identity and trichothecene toxin potential of 151 FGSC isolates collected from wheat in Uruguay were determined via multilocus genotyping. Although F. graminearum with the 15ADON trichothecene type accounted for 86% of the isolates examined, five different FGSC species and all three trichothecene types were identified in this collection. This is the first report of Fusarium asiaticum, Fusarium brasilicum, Fusarium cortaderiae, and Fusarium austroamericanum from Uruguay. In addition, we observed significant (P<. 0.001) regional differences in the composition of FGSC species and trichothecene types within Uruguay. Isolates of F. graminearum with the 15ADON type were the most prevalent in western provinces (95%), while F. asiaticum (43%) and the NIV type (61%) predominated in the new wheat production zone in Cerro Largo along Uruguay's eastern border with Brazil. F. graminearum isolates (15ADON type) were significantly (P<. 0.005) more aggressive on wheat than were isolates from the other species examined (NIV or 3ADON types). However, F. graminearum isolates (15ADON type) were significantly (P<. 0.05) more sensitive to tebuconazole than isolates from other species (NIV type). These results document substantial heterogeneity among the pathogens responsible for FHB in Uruguay. In addition, the regional predominance of the NIV trichothecene type is of significant concern to food safety and indicates that additional monitoring of nivalenol levels in grain may be required. © 2013 Elsevier B.V.


Hartwich F.,Bern University of Applied Sciences | Negro C.,Instituto Nacional Of Investigacion Agropecuaria Inia
Agribusiness | Year: 2010

This study analyzes patterns of collaboration in research and development (R&D) for innovation in New Zealand's dairy industry. Based on a survey of agents contributing to industry innovation, it analyzes existing formal and informal partnerships between R&D organizations and the productive sector and the funding schemes that support such partnerships. The findings suggest that New Zealand's dairy innovation system depends on the capacity of a small number of public and industry agents. Government and industry organizations support innovation initiatives through various funding schemes that do not explicitly foster collaboration, and mechanisms that support informal collaboration are underdeveloped. © 2010 Wiley Periodicals, Inc.

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