Effect of Salinity on Some Growth and Physiological Characteristics of Two Cultivars of Sweet Corn (Zea mays var. saccharata)

In order to evaluate the response of two cultivars of sweet corn to salinity stress a greenhouse experiment was conducted at the Faculty of Agriculture, Shiraz University, in a factorial experiment based on completely randomized design in four replications. Treatments included two cultivars of sweet corn (KSC403 and Passion) and four salinity concentration 0, 25, 50 and 100 mM from NaCl and CaCl2 at a 1:1 ratio. The results showed that with increasing in salinity, plant height decreased and dry weight of both cultivars also decreased however this decline was more pronounced in Passion. KSC403 had more antioxidant enzymes activities and less shoot and root Na concentration compared with Passion. With increasing salinity, CAT and SOD activities of both cultivars decreased and increased, respectively, and POX activity increased to 50 mM of salinity and then decreased. With increasing in salinity level, total leaf chlorophyll decreased although these cultivars were not significantly different in this respect. Naﲯ ratio of root and shoot increased in salinity and this ratio was more in Passion. The superiority of KSC403 in most of the traits could indicate its higher ability to tolerate salinity stress. Lower concentration of Na and more concentration of K in shoot and root of plant can be considered as a criterion in the selection of resistant cultivars to salinity stress.