Investigation of tolerance to water deficit tension of 11 corn hybrids (Zea mays L.) in the seedling stage by measuring antioxidant defense system and physiological traits

Water deficit is one of the most important environment tensions that reduce plant growth. The present experiment was conducted based on split plots based on complete randomized blocks design with three replications during 2019 cropping year at Moghan Agricultural Research Station. Two levels of irrigations as regular irrigation and irrigation cut in the seedling stage (irrigation cut applied during 21 days after plant germination) in the main plots and 11 maize hybrids in the sub-plots were compared. The results indicated that water deficit tension reduced plant height, dry weight, chlorophyll content and water related content in all maize hybrids. The amount of malondialdehyde increased under water deficit tension. However, water deficit tension did not have a significant effect on total polyphenols and hydrogen peroxide. Analysis of electrophoresis activity of antioxidant enzymes on polyacrylamide gel eight percent showed that two and one isoforms for peroxidase and catalase, respectively, in the studied corn hybrids, was observed. Water deficit tension significantly increased the activity of peroxidase and catalase isoforms. It can be concluded that the corn plant reduces the effect of water deficit tension by increasing the activity of the antioxidant and photosynthetic defense system. Based on the obtained results KLM77021 / 4-1-2-1-2-2-4-1 × K47/3 hybrid was identified as the hybrid tolerated to water deficit, compared to the studied corn hybrids.