Genetic diversity is the basis of breeding studies in many plant species and is one of the most
important indicators for selecting parents. The aim of this experiment was to investigate the genetic
diversity of tall fescue (Festuca arundinacea) using agronomic traits such as plant height, spring
growth score, days to flowering, days to pollination, flag leaf length and width, panicle length, weight
of 100 seed and seed yield per plant. The experiment was carried out in a randomized complete block
design with three replications. Based on the results, the ecotypes were significantly different for all of
the evaluated traits with the exception of 100 seed weight. The highest phenotypic variation
coefficient (58.66), genetic variation coeficient (58.32) and heritability (0.97) were related to plant
height. The correlation between traits showed that ecotypes with higher height, panicle length and flag
leaf height and spring growth score have higher seed yield. The results of stepwise regression analysis
showed that in the regression model for seed yield per plant, the panicle length, alone, justified
60.95% of the variation. Cluster analysis grouped 25 ecotypes into three groups. Analysis of variance
of agronomic traits as well as yield and related traits showed that grouping caused mean squares
between groups in all traits (except flag leaf width). In this study, high genetic diversity and high
heritability for evaluated traits showed the potentials of genetic improvement.