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Zaharah S.S.,Curtin University Australia | Singh Z.,Curtin University Australia | Symons G.M.,Agricultural Research and Development | Reid J.B.,University of Tasmania
Postharvest Biology and Technology

The role of abscisic acid (ABA) in triggering ethylene biosynthesis and ripening of mango fruit was investigated by applying ABA [S-(+)- cis,. trans-abscisic acid] and an inhibitor of its biosynthesis [nordihydroguaiaretic acid (NDGA)]. Application of 1. mM ABA accelerated ethylene biosynthesis through promoting the activities of ethylene biosynthesis enzymes (1-aminocyclopropane-1-carboxylic acid synthase, ACS; 1-aminocyclopropane-1-carboxylic acid oxidase, ACO) and accumulation of 1-aminocyclopropane-1-carboxylic acid (ACC), enhanced fruit softening and activity of endo-polygalacturonase and reduced pectin esterase activity in the pulp. The activities of ethylene biosynthesis and softening enzymes were significantly delayed and/or suppressed in the pulp of NDGA-treated fruit. The ABA-treated fruit had higher total sugars and sucrose as well as degradation of total organic acids, and citric and fumaric acids compared with NDGA treatment. These results suggest that ABA is involved in regulating mango fruit ripening and its effects are, at least in part, mediated by changes in ethylene production. © 2012 Elsevier B.V. Source

Zaharah S.S.,Curtin University Australia | Singh Z.,Curtin University Australia | Symons G.M.,Agricultural Research and Development | Reid J.B.,University of Tasmania
Journal of Plant Growth Regulation

Rapid ripening of mango fruit limits its distribution to distant markets. To better understand and perhaps manipulate this process, we investigated the role of plant hormones in modulating climacteric ripening of 'Kensington Pride' mango fruits. Changes in endogenous levels of brassinosteroids (BRs), abscisic acid (ABA), indole-3-acetic acid (IAA), and ethylene and the respiration rate, pulp firmness, and skin color were determined at 2-day intervals during an 8-day ripening period at ambient temperature (21 ± 1°C). We also investigated the effects of exogenously applied epibrassinolide (Epi-BL), (+)-cis, trans-abscisic acid (ABA), and an inhibitor of ABA biosynthesis, nordihydroguaiaretic acid (NDGA), on fruit-ripening parameters such as respiration, ethylene production, fruit softening, and color. Climacteric ethylene production and the respiration peak occurred on the fourth day of ripening. Castasterone and brassinolide were present in only trace amounts in fruit pulp throughout the ripening period. However, the exogenous application of Epi-BL (45 and 60 ng g -1 FW) advanced the onset of the climacteric peaks of ethylene production and respiration rate by 2 and 1 day, respectively, and accelerated fruit color development and softening during the fruit-ripening period. The endogenous level of ABA rose during the climacteric rise stage on the second day of ripening and peaked on the fourth day of ripening. Exogenous ABA promoted fruit color development and softening during ripening compared with the control and the trend was reversed in NDGA-treated fruit. The endogenous IAA level in the fruit pulp was higher during the preclimacteric minimum stage and declined during the climacteric and postclimacteric stages. We speculate that higher levels of endogenous IAA in fruit pulp during the preclimacteric stage and the accumulation of ABA prior to the climacteric stage might switch on ethylene production that triggers fruit ripening. Whilst exogenous Epi-BL promoted fruit ripening, endogenous measurements suggest that changes in BRs levels are unlikely to modulate mango fruit ripening. © 2011 Springer Science+Business Media, LLC. Source

Hucl P.,University of Saskatchewan | Briggs C.,University of Saskatchewan | Graf R.J.,Agriculture and Agri Food Canada | Graf R.J.,Agricultural Research and Development | Chibbar R.N.,University of Saskatchewan
Cereal Chemistry

Canadian Western Red Spring (CWRS) market class is the predominant type of wheat (Triticum aestivum L.) grown in Canada since the turn of the 20th century. Wheat cultivars ranging from cv. Red Fife to cv. Superb were field tested in a series of 24 replicated trials spanning 19 years in central Saskatchewan, Canada. The objective of this study was to measure the rate of cultivar improvement in light of relatively narrow end-use quality definitions for the CWRS market class. Regression of cultivar trait means on year of cultivar registration was used to assess the rate of change in yield, productivity traits, and end-use quality parameters. Yield levels were estimated to be increasing at a rate of approximately 15 kg/ha per year in 1970 and 23 kg/ha per year in 1995. Days to spike emergence and plant height decreased over time. Kernel weight, grain protein concentration, SDS sedimentation volume, farinograph absorption, and dough development time increased over time, whereas farinograph mixing tolerance index and yellow pigment concentration decreased. The results show that improvement in key agronomic and end-use traits has been achieved in CWRS wheat. © 2015 AACC International, Inc. Source

Cho W.-J.,Korea Atomic Energy Research Institute | Song B.-S.,Korea Atomic Energy Research Institute | Lee J.-Y.,Agricultural Research and Development | Kim J.-K.,Agricultural Research and Development | And 5 more authors.
Journal of the Korean Society of Food Science and Nutrition

This study was carried out to investigate proximate compositions, acidity, and soluble solids of various blueberries produced in Korea and to prepare jam with optimized overall palatability by a response surface methodology. Proximate compositions were 75~88% in moisture, 0.32~0.62% in crude protein, 0.12~0.39% in crude lipid, and 10.18~23.80% in carbohydrate. Acidity and soluble solids of blueberries showed 0.82~1.58% and 7~12°Brix, respectively. The effect of sucrose (X1, 200~300 g), pectin (X2, 0~10 g), and citric acid (X3, 0~0.5 g) on overall palatability of blueberry jam were investigated at five levels using a central composite design. Overall palatability of blueberry jam showed maximum score in 200 g blueberry, 248 g sucrose, 4.8 g pectin, and 0.26 g citric acid. Source

Tavassolian I.,University of Adelaide | Tavassolian I.,Shahid Bahonar University of Kerman | Rabiei G.,University of New England of Australia | Gregory D.,University of Adelaide | And 7 more authors.
BMC Genomics

Background: Despite a high genetic similarity to peach, almonds (Prunus dulcis) have a fleshless fruit and edible kernel, produced as a crop for human consumption. While the release of peach genome v1.0 provides an excellent opportunity for almond genetic and genomic studies, well-assessed segregating populations and the respective saturated genetic linkage maps lay the foundation for such studies to be completed in almond.Results: Using an almond intraspecific cross between 'Nonpareil' and 'Lauranne' (N × L), we constructed a moderately saturated map with SSRs, SNPs, ISSRs and RAPDs. The N × L map covered 591.4 cM of the genome with 157 loci. The average marker distance of the map was 4.0 cM. The map displayed high synteny and colinearity with the Prunus T × E reference map in all eight linkage groups (G1-G8). The positions of 14 mapped gene-anchored SNPs corresponded approximately with the positions of homologous sequences in the peach genome v1.0. Analysis of Mendelian segregation ratios showed that 17.9% of markers had significantly skewed genotype ratios at the level of P < 0.05. Due to the large number of skewed markers in the linkage group 7, the potential existence of deleterious gene(s) was assessed in the group. Integrated maps produced by two different mapping methods using JoinMap®3 were compared, and their high degree of similarity was evident despite the positional inconsistency of a few markers.Conclusions: We presented a moderately saturated Australian almond map, which is highly syntenic and collinear with the Prunus reference map and peach genome V1.0. Therefore, the well-assessed almond population reported here can be used to investigate the traits of interest under Australian growing conditions, and provides more information on the almond genome for the international community. © 2010 Tavassolian et al; licensee BioMed Central Ltd. Source

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