estimation of yield potential and genetic variation of orchard grass genotypes (dactylic glomerata)

orchard grass (dactylis glomerata), a pasture and forage grass, has wide genetic distribution in iran. evolution of germplasm and selection of suitable genotypes is the first step for developing adaptable synthetic varieties. in order to investigate production potential, variation and genetic similarity of iranian orchard grass genotypes, an experiment was conducted using clonally propagated materials. genotypes were evaluated for agronomic, phenological and morphological characters under a randomized complete block design during 2005 and 2006. results showed that there are significant differences between genotypes for all of the traits indicating a broad genetic diversity in this germplasem. genotypic coefficients of variability for seed and forage yield were highest while the lowest belonged to phenological traits, plant height and crown diameter. the highest estimates of heritability were observed for days to headings, days to pollination and plant height, while the lowest was for crown diameter. applying cluster analysis on the studied attributes, three groups were obtained. regarding all measured characters the least and the most similar accessions were identified to be used in the further breeding projects. finally, on the basis of the results it can be concluded that clonally evaluations trails can be useful to estimate genetic variation and selection of appropriate parents for conducting advanced breeding programs.