MORPHO-PHYSIOLOGICAL RESPONSES OF MAIZE (ZEA MAYS L.) TO EXOGENOUS SALICYLIC ACID APPLICATION UNDER SALINITY STRESS

The effect of salicylic acid (SA) (0, I and 2 mM) on growth parameters and some physiological characteristics of three maize varieties (S.C704, S.C302 and S.C700) was investigated under salinity stress treatments (0, 50 and 100 mM NaCl). Experimental design was factorial split plot based on completely randomized block design with three replications. Results showed that with increasing salinity to 50 and 100 mM, increased SOD in most varieties. The most of superoxide dismutase activity was measured in S.C302 in 100 mM salt and 2 mM salicylic acid. Salicylic acid enhances the activity of the superoxide dismutase. In S.C704 salinity decreased catalase enzyme activity, but with the use of salicylic acid increased the activity of catalase. By the application of salicylic acid, ascorbate peroxidase enzyme activity increased in all varieties, while salinity reduced enzyme activity. Salinity decreased chlorophyll 'a' content in all varieties. Salinity causes the accumulation of sodium ions in the leaves and roots of the all variety. In S.C704 leaves the most sodium ions was found in 100 mM salt, and salicylic acid reduced the salt accumulation in leaves.