genetic diversity of hulless barley lines and path analysis by grain yield and other agronomic traits

20 hulless barley lines were assessed by grain yield and other agronomic traits in 2006 and 2007 in the research station of the university of tabriz, iran. the experiments in each year were carried out as randomized complete block design with four replications. the genotypes were significantly different for most of the studied traits. this indicated the existence of large genetic variation in the population of hulless barley lines. genotypes 6, 1 and 5 had the highest grain yield. cluster analysis classified lines into three groups. furthermore, principal components analysis confirmed the results of the cluster analysis. the second cluster which included five genotypes, had higher grain yield per plant, per effective tillers and per main spike, no. of grains per spike and effective tillers, harvest index per plant, biomass per plant, no. of effective tillers and weight of main spike. thus the genotypes of this cluster could be used to improve the grain yield of hulless barley in breeding programs. path analysis showed that the direct effect of 1000 grain weight on grain yield per plant was small. number of grains per spike and number of effective tillers had the largest direct effect on grain yield and were regarded as the most important components of grain yield per plant in hulless barley which could be used for selection of better genotypes in segregating generations.