地被植物鹅绒委陵菜的遗传多样性研究

采用RAPD方法对不同海拔和植被盖度下的鹅绒委陵菜（Potentilla anserinaL.）6个种群的遗传多样性水平进行了研究。结果表明,13条随机引物共扩增出132条带,多态性位点为117;鹅绒委陵菜物种水平的遗传多样性较高,且种群间分化明,多态位点比率（88.64%）、Nei’s基因多样性（0.3180）、Shannon信息多样性指数（0.4732）均远高于多数克隆植物。6个种群内的遗传多样性水平变化较大,多态位点在各种群中分布不均衡,种群间分化系数（GST）为47.7%,基因流较低（Nm=0.5482）,多态位点比率在31.06%～74.24%之间,Shannon信息指数在0.1711～0.3625之间,Nei基因多样性指数在0.1164～0.2425之间。多样性水平的变化与海拔没有明显的相关性,而与生境盖度呈显著正相关。从而推断在盖度低、资源丰富的环境中,该物种可能更倾向于克隆繁殖。

Genetic Diversity of Ground Cover Plant Potentilla anserina L.

The random amplified polymorphic DNA（RAPD） technique was employed to analyze the genetic diversity of six populations（20 samples for each population） of Potentilla anserina L.from various altitudes and coverage.The RAPD analysis selected thirteen random primers for the amplification of 132 repetitive loci with 117 polymorphic loci.Genetic diversity at species level was relatively high and there was distinct genetic differentiation among the six populations.The ratio of polymorphic loci（88.64%）,Nei＇s gene diversity（0.3180）,and Shannon＇s information index（0.3997） at the species level were remarkably higher than other clonal plants.Inter-population variations were different and the distribution of polymorphic loci was not average among the six populations.The GST was 47.7%.The gene flow estimated by GST was only 0.5482,which indicated less gene exchange occurred among populations of P.anserina,with PPL ranging from 31.06% to 74.24%,I ranging from 0.1711 to 0.3625,and H ranging from 0.1164 to 0.2425.Correlation analysis showed the changes were positively related with coverage（r=0.8630） but not with altitude.We deduce that P.anserina may be inclined to clonal propagation in the habitat of abundant resources.