Water Stress on Wheat Kernel Size, Color and Protein Composition................. 157 (original) (raw)

Effect of Water Stress on Some Wheat Quantitative Traits and Grain Protein Content

A field trial was conducted during the growing season 2004-005 in three environmentally different sites (AL-Algana, Tal Aswad, and Deir Dejla) of the North Eastern area of Syria to evaluate the response of some bread and durum wheat genotypes to drought and heat stress during the critical stages (Flowering and grain filling) of plant growth and development. A significant genetic variation occurred in the response of investigated wheat genotypes for drought and heat stress tolerance. Increased water stress enhanced the rate of photoassimilates translocation from the stem into grains. The rate of assimilates translocation from stems was less sensitive to drought than the rate of dry matter transportation from leaves into grains. The translocation efficiency was significantly higher in the bread wheat genotypes (Cham4 and Cham6) compared with durum wheat genotypes. Stem weight is considered one of the most important traits associated with drought tolerance and maintaining productivity under limited-water conditions. Durum wheat genotypes exhibited significantly higher 1000-kernel weight, while the grain number per plant and grain yield were significantly higher in bread wheat genotypes. Drought during the grain filling stage caused a substantial increase in the grain protein content, but it was significantly higher in the durum wheat compared with bread wheat genotypes. This might be attributed to the reduction of starch accumulation, which indicates that the rate of nitrogenous compounds accumulation is less susceptible to drought than starch accumulation. Key words: Water stress, Photoassimilates translocation efficiency, Stem weight, Nitrogen harvest index, Water use efficiency (WUE), Wheat.

Comparative Morpho-Biochemical Responses of Wheat Cultivars Sensitive and Tolerant to Water Stress

Water stress is likely the most important factor that adversely affects plant growth and development. In this study two wheat cultivars Gemmieza-7 (sensitive) and Sahel-1 (tolerant) were subjected to water stress and compared in terms of growth parameters (growth vigor of root and shoot), water relations (relative water content and saturation water deficit) and protein as well as nucleic acids (DNA and RNA) content in flag leaves of both cultivars. In general, water stress caused noticeable reduction in almost all growth criteria of root, shoot and flag leaf which was consistent with the progressive alteration in water relations, protein and nucleic acids content of both cultivars during grain filling. Furthermore, degree of leaf succulence and degree of leaf sclerophylly were severely affected by water stress in both wheat cultivars. In relation to wheat cultivar, the sensitive was more affected by water stress than the tolerant one. Generally, the application of salicylic acid, trehalose or their interaction induced marked increase in growth vigor of root and shoot, water relations and protein as well as nucleic acids in flag leaves of both wheat cultivars in compare with control and water stressed plants. In conclusion, Sahel-1 has suitable mechanisms to enable it to respond more effectively to water stress than Gemmieza-7.

Studies on Resistance to Biotic and Abiotic Stresses in Wheat

2016

remain in my heart. I am deeply grateful to my co-supervisor Dr. Urmil Bansal for her incredible guidance and edifying training and suggestions during the course of the research. I am truly indebted to her detailed training and assistance in conducting the molecular research and for her constant advises and counselling during the course of my studentship. My deepest gratitude goes to associate-supervisor Assoc. Prof. Margaret Barbour for professional assistance and implausible training, guidance and support in conducting the physiology experiments. My thoughtful thanks also go to Dr. Peng Zhang for her professional help and guidance in molecular cytology. I also extend my gratefulness to National Agricultural Research Organisation of Uganda for awarding me the scholarship and Grains Research and Development Corporation (GRDC) for funding part of my research. I am forever grateful to Dr. William Wagoire for believing in me and for strongly supporting my bid for further studies. I cherish your professional and parental guidance during the time we worked together and during the course of my PhD study. My special thanks to Emeritus Prof. Robert McIntosh for giving valuable time to discuss my results and suggesting valuable information during the study. My sincere appreciation goes to Profs. Robert Park and Peter Sharp for their advice when I was applying for my PhD program at University of Sydney. I express my cordial thanks to my fellow students and friends

Water stress alters physical and chemical quality in grains of common bean, triticale and wheat

Agricultural Water Management, 2020

Wheat, triticale and common bean are planted in both irrigated and rainfed conditions and may suffer the effects of water stress in both situations. The objective of this work was to evaluate the effect of water stress on the physical and chemical qualities of wheat (Triticum aestivum), triticale (Triticosecale wittmack) and common bean (Phaseolus vulgaris L.) grains. The experiment was conducted at the Embrapa Cerrados experimental station, in Planaltina, DF, Brazil. The experimental design was in randomized blocks with four replications. The treatments were composed of four water regimes (187 mm, 304 mm, 410 mm, 535 mm) applied to common bean (BRS Realce), two wheat genotypes (CPAC 0544 and BRS 404) and triticale (BRS Ulisses). The physical quality of grains was evaluated by the weight of a thousand grains (WTG) and color of the grains (represented by the luminosity (L*), chroma (C*) and hue angle (h*); the chemical quality was determined by protein, carbohydrate, lipid, ash, macro and microminerals contents. Water stress reduced grain yield of all species, however it did not reduce the weight of one thousand grains of the wheat genotype BRS 404, showing the potential of this cultivar, though it did lead to reduced WTG in common bean, triticale and the wheat genotype CPAC 0544. There was also a reduction of luminosity (L*) in the grains for both studied wheat genotypes, and chroma (C*) and hue angle (h*) for triticale. Water deficit also affected protein, carbohydrate, lipid and ash contents, with an increase in the protein content and a reduction in the carbohydrate and ash contents in common bean. In general, water stress reduced macro and micromineral contents in the grains, caused an undesirable change in the physical quality of the grains, and affected the chemical quality of the grains. Among the species with prominence in the world production scenario are the common bean (Phaseolus vulgaris L.) and wheat (Triticum aestivum L.). Common bean is a legume consumed worldwide as an important source of protein, fiber, starch and minerals, such as nitrogen and potassium (Castro-Guerrero et al., 2016), and has high potential for reducing malnutrition in poor populations (Chekanai et al., 2018). Wheat is the second most cultivated crop in the world with a production area estimated of approximately 200 million hectares (Zorb et al., 2018). Wheat consumption accounts for 19 % of the calories in the global human diet, since the grain is rich in carbohydrates whilst also having a higher protein content than other cereals such as rice, maize and rye (Liu et al., 2018; Zorb et al., 2018). Triticale (Triticosecale wittmack), is a man-made cereal, resulting from the cross between wheat and rye, which has been gaining importance in human

Effect of water deficit on accumulation of proteins in wheatseedlings correlates with grain filling

Indian Journal Of Agricultural Research, 2016

Nine genotypes of wheat (Triticum aestivum L.) C 306 PBW 154, PBW 175, PBW 396, WH 542, PBW519, PBW520, PBW527 and PBW528 were screened at seedling stage for water stress tolerance at mild (-0.20MPa) and moderate (-0.40 MPa) water potential. Water stress induced by polyethylene glycol. Dehydrins with molecular mass of 24Kd was observed in C306, PBW 396 and PBW 528. The dehydrin bands were absent in PBW154, PBW175, WH542, PBW519 and PBW520. The selected tolerant and susceptible genotypes differing in their drought tolerance viz.C306,PBW154,PBW519,PBW527 were subjected to soil water deficit stress at two developmental stages in field conditions . The leaves of genotype C306 and PBW 527 accumulated dehydrins of Mw 24Kda and 53Kda C306, PBW527 at tillering as well as anthesis stage water deficit stress. The genotypes C306, PBW 527 have lower value of drought susceptibility index showing more tolerance to water stress as compared to PBW 154, PBW 519.