Antioxidative enzyme activities in maize genotypes grown under saline water irrigation

Abstract

Plants with high levels of antioxidant enzymes have been reported to have greater tolerance to this oxidative damage caused by salinity. Role of antioxidative enzyme activity in salt stress and screening maize hybrids for salinity tolerance was investigated in this study. A pot culture experiment was conducted to evaluate six maize hybrids (CO 6, CO 7, CO 8, CO 10, NK 6240 and 900M gold) for their tolerance to saline water irrigation. The maize hybrids were irrigated with saline water having a natural EC of 0.06, 3.2, 4.8, 6.2 and 8.9 dSm -1 for 30 days and replicated thrice in a FCRD. The antioxidant activities such as catalase (CAT), peroxidase (POX) and superoxy dismutase (SOD) were measured in maize hybrids grown under saline water irrigation besides recording and dry matter production (DMP) and growth attributes. CO 6 and CO 7 were identified as saline tolerant maize hybrids based on their antioxidant enzyme activities and DMP. However CO 8 has been observed as a salt sensitive maize hybrid as it showed lesser enzyme activities and DMP. The order of tolerance exists among the maize hybrids to irrigation water salinity were: CO 6 > CO 7 > NK6240 > 900M gold > CO 10 > CO8. Antioxidant enzyme activities and dry matter production were found to be useful traits for identifying salinity tolerance in maize hybrids at seedling stage.