Evaluation of Diversity and Heritability of Some Morphological Traits in Bread Wheat under Stress and Normal Conditions

In order to investigate genetic diversity and heritability of some morphological traits in five bread wheat (Triticum aestivum L.) cultivars، two separate experiments were conducted based on randomized compeletly blocks design (RCBD) with 3 replications under stress and normal conditions. The results showed that differences between cultivars were significant for the majority of traits in both conditions، that this indicated a high diversity among the cultivars for the above-mentioned traits. The mean compression results showed that tolerant cultivar of Pishgam had the most root length and root dry weight in both conditions. Phenotypic correlation indicated that root length had significant correlation with root fresh weight under normal condition and it showed a positive and significant correlation with leaf length، root number، root fresh weight and root dry weight under stress condition. Stepwise regression showed that، root dry weight، root number and above ground fresh weight to root fresh weight ratio were the main effective traits on root length under stress condition. Furthermore، above ground dry weight to root dry weight ratio and flag leaf area traits had the maximum and the minimum genetic diversity under stress condition، respectively. In addition، root dry weight and root dry weight to root fresh weight ratio traits had the maximum and the minimum heritability، respectively.