Analysis of phenotypic variation of introduced cultivars of tall fescue

To enrich the germplasm resources of tall fescue (Festuca arundinacea) in China, and select elite varieties and breeding parents, we conducted a series of analyses for 19 introduced cultivars of forage-type tall fescue based on 14 phenotypic traits. The analyses comprised descriptive analysis of morphological traits, correlation analysis between morpho-agronomic characteristics, principal component analysis (PCA) and clustering analysis. The main results were as follows: 1) The coefficients of variation (CV) of most traits were higher than 10%, except for the internode number (IN), which demonstrated great differences and/or high diversity among the studied cultivars, and their benefits to future breeding. Owing to the highest CV found in fresh weight per plant, this character could be used to screen out cultivars with high biomass. 2) There are complex correlations among various morphological traits. The higher the plant, the better the performance of production trait, conversely, the stronger the stem of the plant, the better the reproduction traits. 3) Principal component analysis showed that the plant height, leaf size, inflorescence structure, grass yield and seed quality were the main factors influencing the phenotypic variation of tall fescue. According to the results of principal component analysis, 19 tall fescue cultivars, with the exception of Fawn and Kenwell, could be divided into two groups, which was consistent with the cluster results based on UPGMA method. Of the two groups, cultivars of group Ⅰ are suitable for seed production, whereas cultivars of group Ⅱ are suitable for screening high-yield lines or parents.