The effect of salinity stress and salicylic acid on some physiological and biochemical traits of Black cumin (Nigella sativa L.)

Black Cumin (Nigella sativa L.) is an annual plant from the buttercup family that has been used in food industry and cosmetic products in addition to its medicinal value. In this research, the effect of salinity stress and salicylic acid on some physiological and biochemical parameters including Relative Water Content (RWC), ion leakage, malondialdehyde, anthocyanin content, proline, catalase activity and ascorbate peroxides in black cumin (Nigella sativa L.( were investigated. Exprimental treatments consisted of three levels (0 as control, 25 and 75 mM NaCl) and (0 as control, 0.75 and 1.5 mM) for salinity and salicylic acid, respectively. Three to four-leaf seedlings incubated for three weeks under salt stress, during the same period twice sprayed with salicylic acid. The results showed that salinity stress significantly reduced the RWC and anthocyanin, and significantly increased ion leakage malondialdehyde, proline, catalase activity and ascorbate peroxidase activity. While in salt stress condition, salicylic acid treatment increased the RWC, malondialdehyde, anthocyanin, proline, catalase activity and ascorbate peroxidase activity, but ion leakage was decreased. Black Cumin is sensitive to salinity stress, so by applying salicylic acid may increase the antioxidant capacity that can helps to the possibility of plant to growth and survival under stress conditions.