Effect of seed priming on morphological and biochemical characteristics of safflower (Carthamus tinctorius L.) under drought stress

A split plot experiment laid out in RCBD with three replications was used to investigate the effect of seed priming on morphologic and biochemical characteristics of safflower (Carthamus tinctorius L.) under drought stress. The experimental factors included drought stress as the main factor with two levels of appropriate irrigation and withdrawing irrigation at stem elongation stage, and also seed priming methods including osmo-priming, hydro-priming, hormo-priming and control (no priming) and safflower cultivars including Goldasht and Soffe as the secondary factors. The characteristics under investigation were plant height, the number of periphery branches, seed yield, biologic performance, oil percentage, soluble carbohydrates, proline content and superoxide dismutase enzyme activities. Draught stress in the absence of seed priming and under hydro-priming reduced seed yield by 16.91 and 25.86%, respectively; however, no significant effect was observed under osmo-priming and hormo-priming. It was also observed that cultivar Goldasht was more tolerant to drought than cultivar Soffe. The findings suggested that the hydro-primed seed of safflower cultivar Soffe was the best treatment under adequate irrigation as well as drought stress.