Genetic Variations of Leaf Trait in Maize (Zea mays L.) under Drought Stress in Different Growth Stages

Maize is the third most important food crop worldwide, and it is more sensitive to drought. Two field experiments were conducted under drought in different growth stages at two locations, the Demonstration Farm, Faculty of Agriculture, University of Khartoum, at Shambat, and the Gezira Research Station Farm, at Medani, in season (2003/2004). To estimate the pattern of inheritance, determine the relative magnitude of genetic variation effects for a number of leaves/plant and leaf area index in fifteen maize genotypes. A split-plot design, layout within randomized complete block design with three replications was used for the experiment. Significant differences among genotypes were detected in all traits, except, leaf area index (30 and 60 days) and number of leaves/plant (45 days). High genotypic coefficient of variation, genetic advance and heritability were exhibited by a number of leaves/plant for 60 days. Grain yield was significantly and positively associated at the phenotypic level with the leaf area index and a number of leaves/plant at 60 days. Thus the characters leaf area index and number of leaves/plant to be the important traits which would be an effectual in selection for maize improvement under drought stress at different growth stages. Based on their positive association with grain  yield, the traits  leaf area index and number of leaves/plant would be the exploited for improving grain yield and facilitate further efforts in the maize improvement program in the country. Keywords: correlation; heritability; morphological traits; vegetative and reproductive phases; water stres