Impact of water deficit stress on traits influencing the drought tolerance and yield of maize ( Zea mays L.) genotypes

Water deficit stress is one of the major abiotic stresses that severely affects the plant performance and production especially when it occurs during the reproductive phase. That drought research is an ongoing approach as new breeding lines development is a continuous process. Therefore, a field experiment was conducted with recently developed 12 maize ( Zea mays L.) genotypes under Well Water (WW) and Water Deficit stress (WDS) conditions to quantify the impact of WD stress on phenological, physio-biochemical and yield parameters. The results showed that WD stress significantly altered the Anthesis Silking Interval (ASI) among the genotypes but had no effect on the genotypes DTL-4–1 and Harsha. A significant decrease in net photosynthetic rate, stomatal conductance, transpiration rate and WUE was recorded with WD stress. Accumulation of proline under WD stress was significantly higher with DTL-4–1 and Harsha with a lower malondialdehyde (MDA) content and increased activity of SOD thereby maintained better cell membrane stability (CMS). Biomass and grain yield components were also significantly impacted by the water deficit stress. Among the maize genotypes, DTL-4, DTL-4–1 and Harsha showed better Stress tolerance index (STI). Under WD stress, grain yield showed significant positive association with proline, CMS, kernel number while negative association with MDA and ASI, indicating importance of these traits in imparting WD stress tolerance in maize.