Characterization, combining ability and analysis of genetic inheritance of persistence and growth traits in tall fescue

Productivity and persistence in grasses are the results of a complex combination of many variables that affect plant growth all over the growing periods. The genetic variability and inheritance of seasonal productivity, persistence, and summer dormancy and their associations are poorly understood in tall fescue. In this study, half-sib (HS) families of tall fescue derived from polycrosses, along with their corresponding parental genotypes were assessed for agro-morphological traits at three harvests, persistence, and summer dormancy in the field during 2016-2019. High genotypic variation was observed for all the measured traits in the evaluated germplasm. In both parental genotypes and HS families, summer cuts had the lowest values of forage mass than spring and autumn cuts during all years of experiment. Summer dormancy index was negatively correlated with forage production and yield-related traits. Forage mass at three cuts, persistence, and summer dormancy had lower narrow-sense heritability (h(PFM)(2)) than yield-related traits, which indicates that these traits may control by small effects of many genes than yield-related traits. Based on the general combining ability (GCA) and the biplot of principal component analysis (PCA), genotypes 21M and 1E with high forage production were identified as preferable genotypes for forage use, which can be used in other breeding programs. In contrast, genotypes 17M and 4E with low forage productivity and high level of summer dormancy may be suitable for turf application. However, further experiments are needed to assess turf-related traits, root characteristics, survival and their association with summer dormancy in this germplasm. Preferable genotypes for forage use and turf application were identified for future programs.