Genetic Analysis for Drought Tolerance of a Maize Segregant Population by Morphological Traits.

A strategy for developing maize populations showing drought tolerance is evaluating genotypes under drought stress and selects those with high yields. However, selection based upon yield is not effective due to many difficulties for conducting field experiments that control the timing, duration and intensity of drought stress. A feasible strategy to overcome that situation is evaluating genotypes during the dry-season and using side-by-side experiments, where one experiment is conducted under irrigation and the other in an artificial drought stress condition, and selecting the best entries over the two environmental conditions. The aims of this research were to: i) evaluate the performance under irrigation and drought stress of 225-F₃ families derived from the cross between a tolerant and a drought-susceptible maize inbred lines, and ii) asses genetic parameters for six morphological traits. F3-families were evaluated in field experiments in Morelos, Mexico, during the dry-season 2007-08. The evaluation of the families was conducted in side-by-side experiments under irrigation and an artificial drought-stress condition. Experimental design was an Alpha Lattice with two replications per environment. Plant and ear height, male and female flowering, anthesis-silking interval, and grain yield were recorded in both experiments. Analyses of variance were conducted reveling high differences between families for all the traits.