披碱草属四种植物主要形态特征的变异性比较

A Comparative Study on Morphological Variation of Four Species in Elymus L.

应用变异系数、主成分分析、系统聚类分析方法,对披碱草属四种不同生境来源的18个居群的180份材料进行形态特征比较分析。变异系数分析结果表明:(1)披碱草属4种植物的不同居群在形态特征上具有变异性;(2)不同居群内及居群间的形态特征存在一定程度的变异;(3)穗部形态特征中的颖及稃特征是种间和种以下分类的重要依据。主成分分析结果表明:颖长、颖脉数、外稃长、内稃长、小穗长、小穗宽等是种间分类的重要特征指标。系统聚类分析法分析表明:在欧式距离等于5时可将来自不同生境的18个居群分为3类,经鉴定第一类为披碱草和老芒麦,第二类为麦宾草,第三类是圆柱披碱草;其中麦宾草的归类清晰。

Morphological variation of Elymus L. populations which come from different environments was studied with the method of numerical statistics. The statistical methods of coefficient of variance, principal component analysis and the cluster analysis were used. The results showed that there were some differences in the phenotypic characters within and among populations, meanwhile it was proved that the glumes and lemma took important roles in the morphological identification. Through the principal component analysis, the result indicated that the spike characteristics including length of glumes and palea, glume vein, length of lemma and length and width of spikelet were important to measure genetic variance. Applied the hierarchical clustering analysis, when Euclidean distance was five, the 18 different populations were classified into three groups： group one included two species Elymus dahuricus T. and Elymus sibiricus L., group 2 included Elymus excelsus T., group 3 included Elymuscylindricus（Franch. ） Honda; among them the Elymus ecccelsus T. had a clear classification.