Faculty of Agriculture, Shahid Chamran University, Ahvaz
Abstract: (18 Views)
Rapeseed is one of the most important oilseed crops, and its production in arid and semi-arid regions of the country faces serious challenges due to drought stress. Accordingly, the present study was conducted as a split-plot experiment based on a randomized complete block design with four replications at the experimental farm of Shahid Chamran University of Ahvaz during the 2021–22 growing season. The main plot factor consisted of two irrigation regimes (control with a 7-day irrigation interval and drought stress with a 14-day irrigation interval from the flowering stage), while the subplot factor included five commercial cultivars: Hyola 50, Hyola 4815, Hyola 401, Hyola 61, and Trapper. In this study, morphological, physiological, yield-related traits, and oil percentage were evaluated. The results showed that drought stress caused significant reductions of 25% in stomatal conductance, 29% in relative water content, 24% in plant height, 44% in the number of fertile branches, 16% in biological yield, 55% in seed yield, and 9% in oil percentage. In contrast, relative chlorophyll content and canopy temperature increased by 18% and 24%, respectively. Correlation heatmap analysis under normal and drought stress conditions indicated that, in addition to biomass, the physiological traits stomatal conductance and relative water content exhibited the strongest correlations with seed yield among the cultivars. Furthermore, based on multivariate analyses, Hyola 61 and Hyola 50 were identified as the most drought-tolerant cultivars, as they maintained higher levels of physiological and yield-related traits as well as oil percentage under water-deficit conditions.
Pournabi F, Siahpoosh M R, Hassibi P. Evaluation of Morpho-Physiological Responses of Commercial Rapeseed (Brassica napus L.) Cultivars to Drought Stress at the Flowering Stage under Ahvaz Climatic Conditions. فیزیولوژی گیاهان زراعی 2026; 17 (68) :41-59 URL: http://cpj.ahvaz.iau.ir/article-1-1707-en.html