Evaluation of Some Physiological Traits and Oil Yield in Different Safflower Genotypes under Irrigation Interruption

In order to evaluate the safflower genotypes in response to drought stress, a split plot experiment was conducted in a randomized complete block design with three replications in Sarvestan region during 2016 and 2017 growing season. The main plot consisted of two levels of normal irrigation and irrigation interruption from the emergence of the first pods and sub plots including fifteen safflower genotypes. Evaluated indices were included grain yield, relative water content of leaves (RWC), oil content, oil yield and drought tolerance indices. Combined analysis results indicated that water deficit stress had adverse effect on all above indices. Effect of genotypes, also was significant on evaluated indices. Results of combination analysis showed that in two irrigation conditions, Dincer and PI-537598 cultivars had the highest grain yield, RWC and oil yield. Based on GMP and STI drought tolerance indices, Dincer cultivar had the highest GMP and STI, and based on the percentage reduction of grain yield, PI-537636-s genotype (57%) had the least decrease, therefore according to these indices could be considered as the most resistant cultivars.