Genetic Analysis of Water Stress Tolerance and Various Morpho-Physiological Traits in Zea mays L. Using Graphical Approach

Fifty inbred lines of Zea mays L. were screened against water stress in glass house experiment. Six inbred lines selected on the basis of various tolerance levels at seedling stage were hybridized in a diallel mating system. The F1 hybrids along with the parents were evaluated in field under normal and water stress regimes to determine the nature and magnitude of genetic variances and heritability estimates. Highly significant (p<0.01) differences were noted among the genotypes for all the traits studied under both regimes. The scaling test disclosed full adequacy for traits like plant height, ear leaf area, grain yield, Cell Membrane Thermostability (CMT) and net Photosynthetic rate (Pn) under normal condition. Similarly characters like ear leaf area, 100-grain weight, cell membrane thermostability and net photosynthetic rate under water stress condition showed additive genetic effect with partial dominance which suggested that these traits might be useful during selection for developing synthetics. The model was partially adequate for anthesis-silking interval and 100-grain weight under normal condition and plant height, anthesis-silking interval and grain yield under moisture deficit condition. Moderate to high heritability estimates for grain yield and yield related parameters revealed maximum ability to transfer the genes to the next generation.