Study of yield, yield components and tolerance to drought stress in safflower genotypes

In order to study of yield, yield components and tolerance to drought stress, 15 safflower genotypes, and two separate experiments were conducted with a Randomized Complete Block Design with three replications in cropping season 2010-2011 in agriculture research station of Zahak. In non stress experiment, irrigation was applied from planting to physiologic ripening and in stress experiment, from appearance 50 % head to growth terminal, irrigation interrupted. Results showed that under non stressed condition, the highest grain yield obtained from variety Goldasht, TN79-582/2, TN79-634/2, TN79-562 and TN79-5325 genotypes with average yield of 4987, 4940, 4648, 4427 and 4413 kg ha-1, respectively. Under stressed condition the highest seed yield obtained from TN79-5325, TN79-581 genotypes, Goldasht variety, TN79-678 and 2811 Arak variety with average yield of 2623, 2572, 2550, 2510 and 2433 kg ha-1, respectively. Goldasht, 5-TN79-5325 and 1-TN79-678 genotypes had higher grain yield in both conditions and showed the highest rates of STI, GMP and MP indices. Biplot graph, according to principle component analysis (PCA), indicated that tolerant genotypes had high yields, and located near to tolerant indices, therefore these genotypes and indices can be suitable sources and criteria for breeding and assessment drought tolerance in safflower.