垂穗披碱草居群穗部形态多样性研究

对采集自四川、西藏、甘肃、新疆、青海和内蒙古6个省(区)的29份垂穗披碱草的14项穗部性状进行多样性研究。结果表明,14项穗部形态性状的平均变异系数为27.34%,显示垂穗披碱草具有丰富的表型变异。居群总多样性指数H′为1.947,居群平均H′为1.424,则居群间H′为0.523。可见垂穗披碱草居群的遗传多样性主要集中在居群内部(73.14%),居群间的遗传变异较小(26.86%)。聚类分析,可分为种子大、较大、较小、小4种类型,较大居多。经主成分分析,其分布能解释总变异的86.63%,其中外稃长、第一颖芒长、穗宽、内稃长、小穗数、穗长等性状是影响较大的因素,这6个性状指标具有较高的特征向量值,基本可以揭示垂穗披碱草形态总体变异的趋势。垂穗披碱草多样性指数与海拔高度呈极显著正相关关系。

Ear Morphological Diversity of Native Populations of Elymus nutans

14 ear morphological traits were adopled to study morphological diversity of 29 native populations of Elymus nutans collected from Sichuan,Tibet,Gansu,Xinjiang,Qinghai and Inner Mongolia.The results showed that the average variation confficient of 14 ear traits was 27.34%,indicating rich phenotypic differentiation.There was abundant genetic diversity(H′=1.947) among these populations in ear traits,their average H′ was 1.424 within populations,0.523 among the populations.The genetic variation within populations(73.14) was greater than that among populations(26.86%).Ear traits could be divided into four types,which was large,relatively large,small,small through cluster analysis,and large seeds were domain.Principal component analysis indicated that 6 of the ear traits measured(lemma length,awn length of glume,ear width,palea length,spikelet per rachis,ear length) were the main sources of ear variation of the 29 E.nutans.Results of the correlation analysis showed that altitude and diversity index were positive correlated and significant at the 0.01 level.