Assessing thegenetic diversity of two populations of barley under normal and drought stress conditions in seedlling stage using multivariate analyses

To assess the genetic diversity of recombinant inbred lines of barley(Hordeum vulgare L.) under two non-stress and drought stress conditions in seedling stage, two populations,Vada×Susptrit (V×S) with 112 RILs and Cebada Capa×Susptrit (CC×S) with 89 RILs, were studied in completely randomized design with two replication in greenhouse. The traits studied were four physiological traits including leaf relative water content, leaf chlorophyll content, shoot dry weight and leaf temprature.Under drought stress conditions, leaf chlorophyll content also measured in three soil water conditions (%50, %30 and %20 field capasity). According to cluster analysis in both populations, V×S and CC×S, the genotypes were grouped in five and four clustersunder normal and drought stress conditions, respectively. Discrimnant function analysis powerfully confirmed the results of cluster analysis in two populations under both experimental conditions. In the population V×S, the first and second discriminant functions with eigen values significant and more than one justified %78.2 and %93.4 of the total variance under normal and drought stress conditions, respectively.In the population CC×S, the first and second functions with eigen values more than one also justified %78.8 and %90 of the total variationsunder non-stress and drought stress conditions, respectively. Additionally, grouping the studied lines in both populations under two conditions was investigated and confirmed by the Mahalanobis distance. The results of this study showed that discrimnant function analysis is a very usfull multivariate statistical method for evaluating and confirmingthe grouping of barley genotypes under normal and drought stress conditions. The results of current research also showed that there is ahigh and considerable variation in both populations under both conditions, so that these populations can be utilized for mapping quantitative trait loci related to drought tolerance in barley using molecular markers.