Evaluation of Genetic Diversity and Traits Relations in Wheat Cultivars under Drought Stress Using Advanced Statistical Methods

In order to study of genetic diversity and classify physio-agronomic characters under normal irrigation and drought stress in wheat cultivars, 15 cultivars were evaluated in the research farm of University of Mahabad, Iran. According to stepwise regression some of traits entered to final model that as far to correlation coefficients and path analysis regarding, the biggest part of correlation coefficient and direct effect was achieved for number of grains per spike, number spikes per plant with grain yield under two conditions. These traits had the highest indirect effect on the grain yield mutually. So, screening for high value for these traits can bring increase in wheat grain yield under two conditions. Factor analysis detected three and four factors which explained 91.23 and 92.43 percent of the total variation in non-drought stress and drought stress conditions, respectively. In drought stress condition the first factor, second factor, third factor and fourth factors were named as yield component, physiological, biomass and growth, and yield factor respectively. Cluster analysis based on the three and four factors grouped cultivars into the two groups under normal and three groups under drought stress conditions. Generally, tolerant cultivars can be used for direct culture or as parents for create of variation in breeding programs.