云南松主分布区天然群体的遗传多样性及保护单元的构建

以20个云南松天然群体为对象,SSR分析表明云南松遗传变异主要存在于群体内,各群体间的遗传多样性水平差异不显著。基于SSR分子标记遗传多样性分析,根据Nei's遗传相似度,采用逐步聚类优先取样法,分别对初始群体、遗传多样性保护单元和剩余群体进行比较、t检验,以此评价遗传多样性保护单元的代表性。结果表明,利用该方法抽样的群体能很好地代表初始群体的遗传多样性,按30%的群体抽样,等位基因数、有效等位基因数、Shannon's信息指数和期望杂合度的保留率分别达到初始群体的98.03%、105.36%、103.99%和105.56%。保护单元的遗传多样性均高于剩余群体,抽样群体组成的遗传多样性保护单元的效果较好。

Genetic Variation and Conservation Units Analysis in Pinus yunnanensis Natural Populations

The intra-specific variation of 20Pinus yunnanensis Franch. natural populations collected from the main distribution areas was analyzed. The results revealed higher genetic variation within populations than among populations based on SSR data and the genetic variation existed mainly within populations. There were not significantly genetic differences among populations. Based on SSR data and Nei's genetic similarity and the level of genetic diversity, the conservation units of P. yunnanensis were analyzed by using stepwise clustering and preferred sampling. The representativeness of sampling were evaluated by T-test among primary populations, conservation units and remainder populations. The results showed this method was effective to establish the conservation units. The CU6 composed of six P. yunnanensis natural populations had the 30% germplasm samples of primary populations. The retention ratio of number of alleles, effective number of alleles, Shannon's information index and expected heterozygosity were 98.03%, 105.36%, 103.99% and 105.56%, respectively. The genetic diversity of conservation units was higher than the remainder populations, which indicated that the populations sampled from primary populations for conversation units were representative and effective.