饲草型高羊茅引进品种的表型变异分析

Analysis of phenotypic variation of introduced cultivars of tall fescue

为了丰富我国高羊茅(Festuca arundinacea)种质资源,选择优良品种及其育种亲本,本研究对19 个引进饲草型高羊茅品种的14 个表型性状进行了形态性状描述分析、性状间相关分析、主成分分析和聚类分析。结果表明,1)观测的14 个表型性状除茎节数外,变异系数均大于10%,表明品种间差异较大、形态多样性高,其中单株鲜重变异系数最大,有利于产草量等性状的选择。2)各个表型性状间存在复杂的相关性,主要表现为植株越高大,产草量性状就越好;而植株茎秆越粗壮,生殖性状表现就越好。3)主成分分析显示植株高度、叶片大小、花序结构、产草量及种子质量是导致饲草型高羊茅表型变异的主要因素。根据主成分分析结果,除Fawn 和Kenwell 外, 17 份高羊茅品种可以分为两大类群,与基于UPGMA 法聚类分析的结果一致。两大类中,Ⅰ类群适于种子生产,Ⅱ类群则适于筛选高产品系或亲本。

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 morphoagronomic 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.