Morphological Identification and Cluster Analysis of Spike-drooping Germplasm of Elymus

In this paper,49 spike-drooping Elymus germaplasm samples collected from 8 different regions were morphologically identified and classified,and 25 morphological characteristics were also studied by cluster analysis and principal components analysis.The result indicated that these germplasm samples belonged to Elymus sibiricus,Elymus nutans and Elymus breviaristatus,respectively,and there were obvious variations among different populations of the same species.Therefore,E.sibiricus was divided into 4 different groups(ecotypes):typical E.sibiricus,strong multi-flower E.sibiricus,spike-ramosed E.sibiricus and spikelet-densing E.sibiricus;E.nutans was divided into 3 different groups(ecotypes):typical E.nutans,high multi-spikelet E.nutans and spike-ramosed E.sibiricus base on their morphological variations.