Abstract: Morphology analysis is an easy and practical method to understand morphological variation and genetic relationship of materials.Phenotype analysis of 27 morphological traits shows that 17 Bromus tectorum Vahl.germplasm resources from different grassland ecology regions of China have significant genetic variations.Coefficient of variation was 9.13%～54.76%.There is broader variation in spikelet number,tiller number,spikelet number per branching,blade length,stalk diameter and branching length than other morphological traits among tested germplasm.There is less variation in spikelet joint number,rachilla internode length,spikelet length,lemma length,palea length,ligule length,palea breadth,anther length and lemma breadth among tested germplasm compared to other morphological traits.Blade breadth,branching length,blade length,stalk diameter,plant height,floret number per spikelet,floret number,spikelet breadth,anther length and lemma breadth were main factors of morphological variations.Cluster analysis indicates that 17 germplasm resources were classified into four groups according to the correlation of 27 morphological characters.These results not only reveal the genetic relationship of tested materials but also provide scientific basis for the further research of germplasm resources and breeding.

Key words: Bromus catharticus Vahl., Variation, Morphology, Principal components, Cluster

摘要： 为了解不同草原生态区域扁穗雀麦(Bromus catharticus Vahl.)的形态变异及其亲缘关系,对17份种质材料的27个形态性状进行测定和分析。结果显示:其形态遗传变异较高,变异系数范围在9.13%～54.76%之间,变异系数较大的性状有小穗数、分蘖数、分枝着生小穗数、叶片长、秆直径、分枝长和株高等;变异系数较小的性状有穗节数、小穗轴节间长、小穗长、外稃长、内稃长、叶舌长、内稃宽、花药长、第二颖脉数、外稃宽等。叶片宽、分枝长、穗长、叶片长、秆直径、株高、小穗含小花数、小花数、小穗宽、花药长、小穗轴节间长等11个指标对总变异的贡献最大。并对27个性状进行了分类和性状间相关性聚类研究,17份材料聚类分析展示了不同材料间的亲缘关系。此形态变异研究为深入研究种质资源及育种提供了科学依据。

关键词: 扁穗雀麦, 变异, 形态学, 主成分, 聚类