【摘要】 基于随机扩增多态DNA(RAPD)方法分析了青藏高原东南部四川嵩草(Kobresia setchwanensis)4个居群的遗传多样性.14条随机引物共扩增出180个位点数,其中多态性位点138个.结果表明,四川嵩草4个居群的遗传多样性大小与生境有相关性,而与海拔没有明显相关性(P=0.768>0.05,r=-0.232).AMOVA数据表明,四川嵩草的遗传变异主要分布在居群内(77.45%),居群间的遗传变异占总变异的22.55%,遗传分化指数GST也显示了相似的结果(0.2101),这一结果符合风媒异交的繁育系统.从四川嵩草4个居群的遗传距离和聚类分析,以及用NTSYS对四川嵩草4个居群的的遗传距离矩阵与地理距离矩阵间的关系进行Mantel检测,结果表明,各居群间的遗传距离与地理距离之间没有明显相关性(r=0.61211,P=0.9176>0.05).更多还原

【Abstract】 Kobresia setchwanensis is a very important fine pasture and ecological grass in the Qinghai-Tibet plateau.In present study,the genetic diversity of K.setchwanensis collected from east-southern of the Qinghai-Tibet plateau in China,are investigated using RAPD markers.180 loci are identified with 14 oligonucleotide primers,out of which 138 loci are polymorphic.The results show that there is relationship between the habitats and genetic diversity of Kobresia setchwanensis,but there is no correlation between the altitude and genetic diversity(P=0.768>0.05,r=-0.232).AMOVA show that most of the genetic variability(77.45%) reside among individuals within populations,whereas only 22.55% reside among populations.The Gst-values(0.2101) show the similar result.The results accord with outcrossing,wind-pollinated plant.Additionally,compared Nei’s unbiased genetic distance matrix with a corresponding geographic distance matrix,the two matrices are not significantly correlated(r=0.61211,P=0.9176>0.05).更多还原