蒙古冰草遗传多样性的RAPD分析

采用RAPD技术对蒙古冰草（Agropyron mongolicum Keng)6个天然居群和2个栽培品种（系）的45个个体进行了遗传多样性检测。17个引物共检测到101个位点，其中多态位点81个，占80.2%，相对于其它小麦族植物，显示出了较高的遗传多样性，多样性指数（DC）分析的结果表明，遗传多样性在居群内和居群间的分布存在不均衡现象，但总体来看，居群内的遗传变异高于居群间，这是由蒙古冰草异花，风媒传粉的外繁育系统所决定的，在天然居群与栽培品种（系）间，前者的DC值为0.250，后者的DC值为0.181，而且前者的平均遗传距离（0.290)也高于后者（0.213)，表明天然居群间的遗传分化大于栽培品种（系），这与天然居群间环境的异质性密切相关，同时也反映了栽培品种（系）间较近的亲缘关系，UPG-MA聚类分析的结果表明，8个居群基本上可被分为与其生境特点及生长条件相适应的3个类群，反映了自然选择及人工选择对居群间遗传分化的巨大影响。

RAPD analysis of genetic diversity of Agropyron mongolicum

Forty five individuals from six natural populations and two cultivars were used in RAPD analysis.Seventeen primers produced 101 bands in total,81 out of which were polymorphic.The percentage of polymorphic loci was 80.2%,which was higher than that of other species of Triticeae .Diversity coefficient and genetic distance analysis showed that genetic differentiation among 6 natural populations was greater than that between 2 cultivars.Meanwhile,UPGMA cluster analysis indicated that the 8 populations could be divided into 3 groups relevant to their own environments and growing conditions.All results revealed a close correlation between the genetic differentiation among populations and their environments,as well as the enormous effects of the natural and artificial selections on the genetic differentiation.