Abstract In order to investigate the relationship between different traits with single grain yield, 26 genotypes and cultivars of barley and wild barley were studied in a randomized complete block design with 3 replications in the greenhouse of the Faculty of Agriculture, Ilam University. 12 traits including days to 50% flowering, plant height, peduncle length, spike length, flag leaf length, awn length, Number of spikes per plant, number of grains per spike, spike weight, grain weight, biological yield Single grain yield were evaluated. The results of analysis of variance showed that the studied genotypes in all studied traits have a significant difference at the level of one percent. Correlation analysis showed that there was a positive and significant correlation between single plant yield with spike length, spike weight, 100-seed weight and number of spikes per plant and a negative and significant correlation with the number of days to flowering. Also, the results of path analysis showed that 100-seed weight and number of spikes show the most direct and positive effects on single plant yield. In addition, flag leaf length and awn length had the highest indirect effect on single plant yield. PCA analysis showed that the first four factors accounted for 74.9% of the total variance, with each factor accounting for 33.5%, 15.3%, 13.90% and 12.2% of the variance, respectively. Cluster analysis was performed by hierarchical analysis method according to which genotypes were divided into 4 groups.
