Mahsa Rafati Alashti; Shahryar Kazemi; Mojdeh Sadat Khayat Moghadam
Abstract
Drought stress is one of the most important factors in reducing yield and seed quality of rapeseed. The present study chiefly tries to evaluate the effect of application of brassinosteroid on seed yield, oil content, oil yield, and fatty acids profile of rapeseed genotypes under late-season water deficit ...
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Drought stress is one of the most important factors in reducing yield and seed quality of rapeseed. The present study chiefly tries to evaluate the effect of application of brassinosteroid on seed yield, oil content, oil yield, and fatty acids profile of rapeseed genotypes under late-season water deficit stresseen considered. A factorial split-plot test has been conducted in a randomized complete blocks design for two cultivation years (2017-2019) in Karaj, Iran. Experimental treatments include two levels of brassinosteroid (i.e., 0 (control) and 0.1μmol) and two levels of irrigation (full irrigation (control) and withholding irrigation from flowering stage) as factorial in the main plots, and rapeseed genotypes (Nafis, Ahmadi, Okapi, Nima, and Niloufar) as subplots. The levels of oleic acid and linoleic acid in the conditions of application of brassinosteroids have been 0.7% and 11% in full irrigation conditions and 1.1% and 6.4% in withholding irrigation conditions, respectively, compared to the control on the other hand, the use of brassinosteroids in withholding irrigation conditions reduce palmitic acid by 14% compared to the control. Okapi genotype has had the highest and lowest erucic acid and grain yield in irrigation conditions, respectively. Under drought stress conditions, the highest seed yield (3112.3 kg/ha) and the lowest amount of erucic acid (0.26%) belonged to Niloufar genotype. The use of brassinosteroids in both irrigation treatments improve the quality of fatty acids and Niloufar cultivar is recommended in both irrigation conditions
Shahryar Kazemi; mahsa rafati alashti; Ghorban Khodabin
Abstract
In order to study the effect of brassinosteroids on yield and physiological characteristics of rapeseed genotypes under late-season drought stress, a factorial split-plot test is conducted in a randomized complete blocks design with three replicates for two cultivation years (2017-2019) in the research ...
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In order to study the effect of brassinosteroids on yield and physiological characteristics of rapeseed genotypes under late-season drought stress, a factorial split-plot test is conducted in a randomized complete blocks design with three replicates for two cultivation years (2017-2019) in the research farm of Islamic Azad University, Karaj (Mahdasht). Experimental treatments include two levels of brassinosteroid (0 (the control) and 0.1 μmol) and two levels of irrigation (full irrigation (the control) and withholding irrigation from 50% flowering stage) as factorial in the main plots, with rapeseed genotypes (Nafis, Ahmadi, Okapi, Nima, and Niloofar) being considered as subplots. Foliar application of brassinosteroid under both full irrigation and withholding irrigation from the flowering stage increase seed yield, chlorophyll, and relative water content, compared to the control. The highest amount of soluble carbohydrates, leaf proline, and oil percentage have been obtained under drought stress and brassinosteroid application, i.e. 24.8%, 16.5%, and 2.5%, respectively, compared to the control conditions. However, Okapi genotype has had the highest stomatal resistance (24.59 s/cm), the lowest chlorophyll (1.49 μmolg-1FW), and seed yield (1960.5 kg/ha) in the conditions of withholding irrigation. Niloufar genotype has had the lowest stomatal resistance, the highest chlorophyll, oil percentage, and seed yield in both irrigation conditions. In general, in both irrigation treatments, the use of brassinosteroids improve physiological traits of rapeseed.