Multivariate analysis some quantitative traits in maize inbred lines under heat stress condition

In order to determine the best index for evaluating maize genotypes, 15 maize inbred lines were evaluated in two planting dates, 6 July to coincide heat stress with pollination time and 27 July as normal planting to avoid high temperature during pollination and grain filling period, using a randomized complete block design with three replications, in Shushtar city, in 2007. Result showed that in stepwise regression analysis for heat stress condition, grain number per ear was the single trait that entered in model but, for normal condition, grain number per ear, hektolitr weight and 1000 grain weight were entered in model, respectively. Factor analysis, for heat stress and normal conditions indentified four independent factors which explained 81.92 and 82.90 percent of all variations, respectively. Under both, heat stress and normal conditions, first factor yield, second factor ear morphology and third factor grain characteristic named. But fourth factor in stress condition hektolitr weight and grain moisture percent and in normal condition grain moisture percent, hektolitr weight and grain width named. Based on the results, grain number per ear under heat stress and grain number per ear and 1000 grain weight, revealed as suitable traits which can discriminate maize genotypes.