神农架自然保护区核桃居群遗传多样性研究

Genetic diversity analysis on genetic diversity of Juglans regia population in Shennongjia Nature Reserve

为有效挖掘湖北神农架核桃(Juglans regia)的种质资源,采用12对多态性高的SSR分子标记引物对3个神农架核桃居群90个单株的遗传多样性及其种群内、种群间的遗传分化进行研究。结果表明:用12对针对核桃属植物基因组设计的SSR引物共检测到108条谱带,其中多态带占比为100%。遗传多样性分析结果显示:居群总期望杂合度为0.604,其遗传多样性水平较高,很可能蕴含了稀有基因资源。遗传分化系数(Fst)显示:有8.22%的变异存在于3个居群间,遗传分化程度中等。这可能与3个居群的地理距离远有关。部分位点显示出居群总体有杂合不足的现象。聚类分析结果显示:居群之间的遗传距离与地理距离具有较高的一致性。

To exploit the walnut （Juglans regia） germplasm in Shennongjia Nature Reserve, the genetic diversity and genetic structure of walnut populations were studied based on 12 SSR markers. 108 alleles from 90 walnut trees of three walnut populations were amplified, and the proportion of polymorphism was 100%. The fact that level of total expectation heterozygosity （He） was 0.604, showed a moderate genetic diversity, and suggested a high probability of rare germplasm in the populations. Analysis from molecular variance revealed a significant genetic variation （Fst=0.082 2） among populations of walnut, which indicated a moderate differentiation of populations, this might cause by geographic isolation on the three populations, and some locus also suggested a heterozygous deficiency among all the samples. The cluster results showed that the genetic distances among the three populations were consistent with their geographic distance.