DETECTION OF SALINE TOLERANT WHEAT CULTIVARS (TRITICUM AESTIVUM L.) USING LIPID PEROXIDATION, ANTIOXIDANT DEFENSE SYSTEM, GLYCINE-BETAINE AND PROLINE CONTENTS

Salt produces free radicals in the plants and these free radicals are scavenged by the antioxidative capacity of the plant. Change in antioxidant activity, phenolic contents, lipid peroxidation, glycine betaine and proline contents were investigated in fifteen genotypes of wheat differing in salt tolerance. The results revealed that the aqueous extracts of wheat (300 mu g/ml) in control and under salt stress (i.e. electrical conductivity, 2 EC, 4 EC, 8 EC and 16 EC) demonstrated antioxidant activity in DPPH radical assay and their increased scavenging percentage showed that AUQAB-2000, PIRSABAK-05, BAKHAR-2002 can be considered as salt tolerant varieties. The change of phenolic content suggests that wheat uses antioxidant properties of phenolics as a mechanism of salt stress. Whereas, the lipid peroxidation, proline and glycine betaine data has indicated that AUQAB-2000, PUNJAB-85, PIRSABAK-05, BAKHAR-2002, FARKHARE-SARHAD and KAGHAN-94 can be considered as salt tolerant varieties. Salt tolerant varieties also showed higher amount of yield at different salinity levels. These results indicate that these cultivars of wheat alleviate the deleterious effect of salt stress by their antioxidant activity and increased production of proline and betaine.