Effect of different seed priming on germination traits in Black cumin (Nigella sativa) under salinity stress

In order to evaluate the effect of priming on germination of Black cumin under different levels of salinity, a factorial experiment on base of completely randomized design was conducted with three replications. The main factors consisted of five levels of priming (osmopraiming with KNO3 (1 and 3%), salicylic acid (SA) (0.2 and 0.5 mM) and a hydropriming)) and four salinity levels (zero, 75, 125 and 175 mM of NaCl), respectively. With out Stress condition, the highest percentage and rate of germination was obtained by 3% KNO3 priming and the highest length and weight of shoot and rootlet and seed vigor by hydropriming. In saline with 75 mM NaCl, 1% KNO3 priming resulted to increase in rate and percentage of germination and seed reserves were consumed. Maximum shoot length and seed vigor were also associated to hydropriming and priming with 0.5 mM (SA) had more shoot weight and conversion efficiency of seed reserves. With increasing salt concentration to 125 mM, 3% KNO3 priming improved germination, vigor, and shoot and rootlet length. Priming with 0.5 mM (SA) had more weight of transferred reserves and in 0.2 mM (SA) priming the highest shoot weight was observed. At the highest level of salinity (175 mM NaCl), priming with 3% KNO3, showed a higher shoot length, vigor and weight of rootlet. The highest germination percentage was observed with the use hydropriming. Maximum weight of consumption seed reserves was belonge to 0.5 mM SA, and 0.2 mM SA, showed higher shoot and rootlet length and weight.