Genetic inheritance of grain yield and its related traits in maize (Zea mays l.) under water deficit

Abstract

Drought stress is one of the major yield limiting factors and causes significant yield losses in different crops. This study was conducted to screen the 50 maize accessions of diverse origin of Pakistan against moisture deficit on the basis of their performance vis., plant height, cob length, kernel rows per ear, kernels per ear, leaf area, days to 50% anthesis, grain yield, 100-seed weight, chlorophyll contents, stomata size, harvest index and drought index. Drought stress was imposed through alternate irrigation (10 recommended irrigations) and normal irrigation (no drought stress) (15 recommended irrigations). The germplasm consisting of 8 parents and 15 crosses was evaluated in field under normal and water deficit conditions in spring season. Out of these 50 accessions five drought and three drought sensitive lines were selected. The selected drought resistant lines were crossed with drought sensitive lines (testers) in line × tester mating design and were evaluated on the basis of yield and yield contributing traits. The inbred lines W64TMS and W82-3 expressed higher general combining ability (GCA) for grain yield, and other yield related traits (cobs per plant, grains per cob, 100-seed weight) under normal and water deficit conditions. The F1 hybrids W64TMS × USSR150 and W82-3 × 150P-1 showed higher specific combining ability (SCA) for grain yield and other related traits under normal and drought stress. Positive correlation was observed between grain yield and cob length, cob diameter, kernel rows per ear, kernels per ear, plant height, number of leaves per plant, leaf area, chlorophyll content, 100-seed weight, stomata size and stomata frequency. It was suggested that the present breeding material may be used for the improvement of grain yield and water deficit tolerance in maize.