Evaluation of diversity of agro-morphological traits under optimal and limited irrigation conditions and grouping of foreign barley germplasm using multivariate statistical methods

In order to study of genetic diversity and classify barley cultivars under optimal and limited irrigation conditions an experiment was evaluated on 138 barley cultivars using alpha latis design with two replications at research field of Tehran University. Result of analysis of variance showed that there are highly significant differences among cultivars in studied traits which reveal high genetic variation among the cultivars. According to stepwise regression and path analysis, under optimal irrigation condition, seed number per plant and biological yield, and under limited irrigation condition biological yield and harvest index were the most important traits affecting grain yield. Factor analysis showed that in both optimal and limited irrigation conditions four factors were selected, which explained 80.33 and 79.93% of the changes, respectively. In both cases, the first factor was named as the performance factor explanation the most data changes. According to the biplot diagram, in optimal condition, cultivars 54, 57, 37, 103, 31, 30, 2 and 29 , and in limited irrigation, cultivars 130, 127, 124, 97, 122, 99, 29 and 55 which were at a high level in terms of the first and second factors, were selected as superior cultivars. Cluster analysis in n under optimal and limited irrigation conditions grouped cultivars into four and five clusters respectively. Which the results of cluster analysis confirmed grouping cultivars based on biplot diagram.