Abstract: The statistical methods of cluster analysis and the Principal Component Analysis (PCA) were used to study 28 morphological characteristics from 40 populations of 9 species of Elymus spp in China. The results showed that 40 populations could be divided into two groups at 0.78 coefficient of genetic distance. One group mainly consisted of the materials of erect ears, the other nutant ears. The populations within each of 9 E.species could be clustered and related to their geographical origin. There were greater variation among E.dahuricus、E.cylindricus and E.purpuraristatus, but distinct taxonomic character between E.nutans and E.sibiricus. Seventeen eigenvectors about the utilization and taxonomic character, was accounted for more than 85% of the total variation, and divided into 10 groups based on their contributed variation. The morphological characteristics of the Elymus spp consisted of the single plant weight, single ear weight, tiller number, reproduction shoot length, distance between boot leaf and ear, ear color, spikelet length, lemma, awn length, spikelet width, ear width, growth rate during seedling stage, glume width, plant villus grade, growth rate from seedling to tiller, leaf color and plant height.

Key words: Elymus spp., Morphological characteristics, Cluster analysis, Principal component analysis

摘要： 以我国9种披碱草的40个居群为材料,对28个形态特征进行聚类和主成分分析。结果表明:以遗传距离系数0.78为尺度把40个披碱草居群分为两大类,第1类主要包括垂穗组披碱草种类,第2类大多数包括穗直立的披碱草种类。披碱草属每个种的各居群基本能够聚在一起,并和地理条件有一定的关系;披碱草(Elymus dahuricus)、圆柱披碱草(E.cylindricus)和紫芒披碱草(E.purpuraristatus)变异性很大,而垂穗披碱草(E.nutans)、老芒麦(E.sibiricus)归类比较清晰明显;在形态分化的指标中,与生产应用及分类功能联系密切的17个特征向量可反映总变异85%以上的信息,根据贡献的大小分为10个不同的层次;单株重、单穗重、分蘖数、生殖枝长、旗叶与穗基部长度、穗色、小穗长、外稃、芒长、小穗宽、穗宽、生长速度(出苗-幼苗)、颖宽、植株绒毛分级、生长速度(幼苗-分蘖)、叶片颜色和株高是披碱草形态分化的主要指标。

关键词: 披碱草属, 形态特征, 聚类, 主成分分析