Partitioning of dry matter and morpho-physiological reactions of bread wheat cultivars committed to drought conditions at different stages of growth

Akbari Moghaddam, H. (2013) Partitioning of dry matter and morpho-physiological reactions of bread wheat cultivars committed to drought conditions at different stages of growth. Doctoral thesis, University of Zabol.

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Plant organs. As dry stress in vegetative stages of growth caused to increase the percentage of root dry weight and to decrease leaf dry weight. On the other hand, it caused to be dominant the percentage of material partitioning in roots to the aboveground parts. Stress in reproductive stage caused a decrease in the percentage of leaf and root dry weights while an increase in stem and spike dry weights. Chamran and Hamoon cultivars containing high dry matter and also had an usual partitioning percentage in their organs before flowering stage, showed a high grain yield after complete ripening (grain filling) in both usual and stressed irrigation conditions because of partitioning more photosynthetic matters to spikes. Hirmand cultivar had no appropriate partitioning of dry matter, so had the lowest grain yield. There was a positive correlation and significance in grain yield, total dry matter, leaf dry weight, stem dry, spike weight and root dry weight, and a negative correlation and significance existed partitioning coefficient of root. The result of physiological investigations revealed that under dry stress in vegetative stages, relative water content (RWC) and foliar chlorophyll content (SPAD) decreased while stomatal resistance and canopy temperature increased. The more the stress is, the more the severity of the decrease and increase of the mentioned issues. Therefore, they are susceptible to changes of soil water and leaf water potential under dry stress. Chamran cultivar had more RWC and SPAD, but less stomatal resistance and canopy temperature. A significant correlation (P<0.01) existed between grain yield, and RWC, stomatal resistance, SPAD and canopy temperature. The result of biochemical analysis showed that drought stress causes to increase proline concentration and soluble carbohydrates in wheat cultivars. Proline accumulation in control treatment in different stages of growth was less than the stressed treatments. Stress caused a reduction in chlorophyll A and B and the total leaf chlorophyll. The highest chlorophyll level was observed in flowering stage. Chamran cultivar consisted of the lowest proline concentration and soluble carbohydrates but the highest chlorophyll concentration than other cultivars in all irrigation regimes tested. Grain yield had a negative correlation to the leaf proline level and soluble carbohydrates. It seems that Chamran cultivar because of having efficient dry matter partitioning to the vegetative and reproductive organs was more fertile than other wheat cultivars. Therefore, partitioning percentages of dry matter to spike، SPAD, canopy temperature, RWC and proline are appropriate scales to evaluate wheat genotypes of high yield in the areas where are under drought stresses.

Item Type: Thesis (Doctoral)
Uncontrolled Keywords: Stress, RWC, Proline, Dry matter partitioning, Grain yield, Wheat
Subjects: S Agriculture > SB Plant culture
Depositing User: admin admin1 admin2
Date Deposited: 01 Nov 2016 07:42
Last Modified: 01 Nov 2016 07:42

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