Effect of Drought Stress After Flowering Period on Morpho-Physiological Characteristics and Yield of Some Winter Genotypes of Rapeseed (Brassica napus L.) in Field Condition

Drought stress is one of the important factors that inhibit growth and yield reduction in rapeseed. This research was conducted to study the morphological and physiology characteristics of winter rapeseed genotypes under control and drought stress conditions. The experiment was performed-based on randomized complete block design with three replications in 2016 at Borujerd agricultural research campus. The results of combined analysis showed that genotype and environment interaction was significant for some traits such as grain yield, flowering period, number of days to flowering and seedling period at 1% probability level. On the other hand, genotype and environment interaction for Chlorophyll was significant at 5% probability level. The results of mean comparisons showed that 1142 genotype had the least grain yield in both control and drought stress conditions. L72 genotype had the highest grain yield under drought stress condition. Growth to flowering and seedling period traits with 94% and 97% in control and drought stress, respectively, had the highest general heritability. In factor analysis, under control and drought stress conditions, the first to fourth and the first to third factors had 82% and 72% of total variance, respectively. Under control and drought stress conditions, the highest genetic distance was observed between genotypes 1139 with Ahmadi and 1139 with 1144, respectively. As a result, genotypes with more genetic distance than each other can be used as candidates for breeding programs in the future.