Nitrogen rates and water stress effects on production, lipid peroxidation and antioxidative enzyme activities in two maize (Zea mays L.) genotypes

Effects of nitrogen rates and water stress ( WS) on production, lipid peroxidation and antioxidative enzyme activities in two maize ( Zea mays L.) genotypes were assessed at different stages under two levels of water supply conditions. WS caused a significant decline in dry matter, grain yield and activities of superoxide dismutase ( SOD), peroxidase ( POD) and catalase ( CAT) whereas a marked rise in malondialdehyde ( MDA) concentration was observed in leaves for the two genotypes. However, the responses of the two varieties to WS were different: significantly higher dry matter, grain yield and antioxidative enzyme activities and lower MDA content were observed for Shaandan 9 than Shaandan 911, therefore the former could be treated as a drought tolerance variety comparatively. A better correlation was obtained amongst dry matter, grain yield and physiological traits. The addition of nitrogen increased dry matter and grain yield as well as activities of SOD, POD and CAT to di. erent levels and significantly decreased MDA content under WS. These e. ects were higher for Shaandan 911 than for Shaandan 9. Furthermore, a signi. cant e. effecy found for Shaandan 911 between N rates for all traits unlike Shaandan 9. Hence, we suggest that nitrogen should be applied to a water-sensitive variety to bring out its potential fully under drought.