Abstract: Leymus chinensis (Trin.) Tzvel. is not only an excellent forage species but also an important ecological grass. Identification of excellent L. chinensis germplasm with high yield per ramet and strong clonal fecundity of rhizome is of great significance for artificial L. chinensis grassland construction and degraded grassland improvement. In this paper,66 accessions of L.chinensis were used as experimental materials,and were cultivated in the experimental garden. Based on 17 quantitative traits related to agronomy and reproduction,principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to identify the fine L. chinensis germplasm,and the bioclimatic and geographical distribution of L. chinensis germplasms were analyzed. Ten excellent L.chinensis germplasms with advantages of spatial expansion of the rhizome,yield per ramet,number of clonal offsprings,leaf length and integrated performance were identified. One specific variety of L.chinensis with the super clonal rhizome multiplication was found. Our results indicated that fine L. chinensis germplasms mainly originated from central Inner Mongolia and the west of Heilongjiang Province,where the annual mean temperature and the annual mean precipitation are relatively high. This study not only provided a reference for investigation and collection of L.chinensis germplasm resources,but also provided basic data for the development and breeding of new varieties of L.chinensis.

Key words: Leymus chinensis, Germplasm, Identification, Clonal growth, Rhizome

摘要： 羊草（Leymus chinensis）是禾本科优良牧草，也是重要的生态草种。单株产量高、根茎克隆繁殖力强的优良羊草种质的筛选对于羊草人工草地建植和退化草地修复具有重要意义。本文以66份野生羊草为试验材料，在试验地栽培条件下，基于农艺和繁殖相关17个数量性状，采用主成分分析（PCA）和系统聚类分析（HCA）法，进行优良羊草种质的筛选，并进行羊草种质的生物气候和地理分布分析，筛选出根茎空间扩展力、单株产量、克隆后代数、叶长和综合性能方面具有优势的优良羊草种质各10份，获得根茎克隆繁殖力强的特异性羊草种质1份。优良羊草种质主要来源于年平均气温相对较高、年平均降水量相对较多的内蒙古中部和黑龙江省西部地区。本研究为羊草种质资源调查和收集提供了参考，为选育和开发羊草新品种提供了基础资料。

关键词: 羊草, 种质资源, 筛选, 克隆生长, 根茎