Genetic diversity of durum wheat landraces using multivariate analysis under normal irrigation and drought stress conditions

To evaluate the genetic diversity in 37 durum wheat landraces originated from Iran and Azerbaijan, an experiment based on randomized complete block design with three replications was carried out in normal irrigation and drought stress conditions in agricultural research station of Islamic Azad University, Ardabil, Iran. Analysis of variance indicated that there were highly significant differences among the genotypes in all of the traits. Environment mean squares were significant for all the traits studied showing that the drought stress has significant effect on all the traits. The heritability estimates were high for plant height in both conditions. In regression analysis (stepwise method) under stress, number of grains per spike and plant height remained in final model (R2 = 0.634). In well-watered condition biological yield, awn length and harvest index showed more direct positive effects on yield. In drought stress condition, biological yield, spike length, number of grains per spike and harvest index showed more direct positive effects on yield. Harvest index showed the highest indirect effect on yield in two conditions. Cluster analysis, divided the genotypes into three groups in each condition. Classifying the results of the cluster analysis identified bagh oliya, naxcevan and chakmak genotypes in stress condition which confirm the results of the compared means yield. Key words: Genetic diversity, heritability, landrace, path analysis, yield.