Application of EST-derived microsatellite markers for analysis of genetic variation in tall fescue and its comparison with morphological markers

Analysis of genetic diversity in germplasm collections is an important component of crop improvement programs. This study was conducted to analyze genetic variation and to classify tall fescue genotypes based on phenotypic evaluation and EST-SSR molecular markers. Twenty-five genotypes were assessed based on phenotypic and 42 EST-SSR molecular markers according to a completely randomized block design with three replications during eight years (2007-2014). Results indicated that the effect of year, genotype and their interaction were significant for all of the measured traits. Both morphological and molecular assessments showed considerable genetic variation among genotypes. The estimates of broad-sense heritability (h2b) were moderate to high (h2b = 42.1-78.4) for the traits studied. Based on EST-SRR analysis, a total number of 229 alleles were detected with an average of 4.58 alleles per marker. Average PIC value was 0.49 with a range of 0.014 for NFA140 to 0.95 for NFA047. Phenotypic evaluations and EST-SSR molecular marker classified genotypes into 3 and 7 clusters, respectively which mainly supported geographical origins. The general correspondence was observed between morphological and molecular classification. Therefore, combining the molecular markers with morphological responses could be more beneficial to describe genetic variation and distinguish superior genotypes for future breeding programs.