退化梯度对克氏针茅种群遗传分化的影响

Genetic Differentiation of Stipa Krylovii in Different Degraded Soil

对重度退化、轻度退化和正常样地的克氏针茅种群进行 RAPD研究。结果表明 ,3个种群扩增条带总数、多态位点比率、种群内稀有位点数、遗传多样性和基因多样性均是正常种群 >轻度退化种群 >重度退化种群。用Shannon指数估算 3个种群的遗传多样性 ,其中 72 .39%的遗传变异存在于种群内 ,2 6 .89%存在于种群间。重度退化与轻度退化种群 ,重度退化与正常种群间的遗传相似系数分别为 0 .8993和 0 .815 9。在重度退化情况下克氏针茅种群遗传结构发生了一定的遗传分化。

Using DNA (RAPD) analysis, a study of 3 Stipa kryvolii populations from a plot of heavily degraded grassland, a plot of lightly degraded grassland, and one of normal conditions was undertaken. The result shows that the sequence in terms of the total amplified bands, polymorphic loci percentage, rare loci numbers within each population, genetic diversity, and gene diversity among the 3 populations is: those of the normal grassland>lightly degraded one>heavily degraded one. Shannon index indicates that 72.39% genetic diversity exist within each population, while only 26.89% exist among the populations. The phenotypic similarity coefficiency between the heavily degraded grassland population and the lightly degraded one amounts to 0.8993, and that between the heavily degraded and the normal condition ones is 0.8159. Heavy degradation conditions appear to lead to some genetic differentiation in the genetic structure of Stipa krylovii.