中文摘要：

对采自云南省的25份野生种质和4份驯化栽培种质中型狼尾草材料的16个主要表型性状进行多样性分析,为其相关特性和优良种质资源的筛选提供基础资料。结果表明,中型狼尾草各表型在29份材料间均表现出极显著差异（P〈0.01）,存在着丰富的表型多样性和变异水平,平均变异系数为17.58%,离散程度较高,极差变幅为0.31～51.60。主成分分析表明,叶长、穗长、穗宽、穗柄长、节间长等茎叶与穗部营养性状的变异是中型狼尾草表型变异的主要来源和贡献者,种子相关性状发芽率和结实率的变异程度低,遗传稳定。基于形态性状,把29份中型狼尾草种质聚类并划分为3大居群,聚类结果在一定程度上受到环境因子的影响。依据研究结果,对中型狼尾草种质资源的保护和育种亲本的选择策略给予建议。

英文摘要：

The phenotypic diversity of 25 wild accessions from Yunnan and 4domesticated cultivation accessions of Pennisetum longissimum var.intermediumin Gansu were analyzed based on 16 phenotypic traits to provide basic data for selecting the related characters of excellent resources.The results showed there were highly significant differences in phenotypic traits within 29accessions（P〈0.01）.The average variation coefficient and the range of 16 phenotypic traits with 17.58% and 0.31-51.60 respectively,which showed there was relatively higher variation and discrete degree of morphological characters in the species.The principal component analysis of phenotypic traits indicated the traits including leaf length,spikelet length,spikelet width,peduncle length and internode length were the main factors account for phenotypic variations.The variation of seed traits such as germination percentage and seed setting rate was lower and stable.The cluster analysis showed 29 tested accessionswere divided into three groups in general,each group included 9,12 and 8accessions respectively.Then to a certain extent,clustering results were affected by environmental factors.According to above results,the protection measures of germplasm resources and the selection strategies of breeding parents for Pennisetum longissimum var.intermedium were discussed in the end.