Investigating effect of salicylic acid on germination and activity of some enzymes antioxidant of Nigella sativa L. under salt stress conditions

In order to investigate the effect of salicylic acid on germination properties under salinity conditions, a factorial design based on complementary randomized design with three replications. The test factors consisted of salicylic acid at three levels (zero, 0.75 and 1.5 millimolar) and salinity stress at five levels (0, 100, 200, 300 and 400 millimolar). The effects of salicylic acid and salinity stress on seed vigor index, fresh weight and seedling dry weight were significant. The effects of salicylic acid and salinity on other traits were significant at 1% probability level. The results showed that salinity significantly reduced germination and seedling growth, but salicylic acid improved germination indices and increased germination in stressed treatments. With increasing salinity stress, the rate and germination percentage decreased. The maximum rate of germination was obtained in saline silicic acid (1.5mM) treatment under non salinity conditions. Pre-treatment significantly increased the activity of catalase enzyme compared to pretreatment and decreased malondialdehyde in salicylic acid treatments. Pre-treatment at a concentration of 1.5 (mM), while also having more effect on germination, increased the resistance of seedlings of Nigella sativa under salinity stress.