Effect of salt stress on antioxidant enzymes, photosynthetic pigments and proline in commercial varieties of maize (Zea mays L.)

This study was conducted to determinethe effect of different levels of salinity on some physiological traits in eight cultivars of corn in factorial experiment based on randomized complete block design in three replication and several traits of sodium ion (Na+)concentration in leaf, chlorophyll a, and b, proline and antioxidant enzymes were measured. K3653/2 cultivar was blighted in salinity concentration of 50 mM which showed its sensitivity to salinity and was removed from the study. There was a significant difference between different salinity on chlorophyll a and b, the content of sodium in leaf, ascorbate peroxidase and superoxide dismutase. The highest amount of chlorophyll a was obtained in K3615/1 in normal condition. The amount of superoxide dismutase increased with increasing salinity and the highest amount of this enzyme was observed in salinity concentration of 100 mM. There wasnt any significant difference among cultivars in terms of superoxide dismutase in salinity concentration of 100 mM. The increase of salinity concentration level increased the amount of proline in most cultivars. The highest level of proline was obtained from K3545/6, Zaqatala, SC302 and SC704 cultivars in salinity concentration of 100 mM. The maximum amount of ascorbate peroxidase enzyme was obtained from SC302 and Waxy cultivars in normal conditions. There wasnt any significant difference among cultivars in terms of Na+ content in normal condition. Two cultivars of Zaqatala and SC704 showed more resistance to salinity, Therefore they can be used in breeding programs.