利用SSR分子标记分析茶树地方品种的遗传多样性

正确评价茶树地方品种的遗传多样性是有效保护和利用茶树地方品种的前提条件。本研究从西湖龙井群体种中选取91个单株，用SSR分子标记分析其遗传多样性。采用计算机模拟方法，探讨了抽样群体样本量、SSR引物等位基因数影响茶树地方品种的主要遗传多样性参数值的变化规律。结果表明，样本量对茶树地方品种的遗传多样性参数值有不同程度的影响，当样本量达到15个单株时，各遗传参数值趋于稳定；SSR引物等位基因数对茶树地方品种各遗传多样性参数值的影响很大，而且达到总体遗传多样性90%所需的样本量也很不一样。当SSR引物等位基因数为5时，24个茶树单株才能达到茶树地方品种总体90%以上的遗传变异。本研究为茶树地方品种遗传多样性的评价和采用合理的保护策略提供了科学依据。

Genetic Diversity of Tea Landraces Using SSR Markers

Appropriate assessment of genetic diversity in tea landraces is the prerequisite of conservation and utilization of these valuable genetic resources. Ninety-one individual tea plants, from Longjing tea landrace population, were used in this study. Computer simulation was utilized to study the changes of genetic diversity parameters influenced by the number of samples and alleles per SSR locus. The results showed that the sampling number differentially affected the genetic diversity parameters. Only when the sample number was higher than 15, the parameters tended to be stable. There were also large effects of the number of alleles per SSR locus on the genetic diversity, which was closely associated with the sample number. It was found when the number of alleles per SSR locus was five, at least 24 individual tea plants were needed for reaching to 90% of the total genetic diversity of tea landraces. The results are useful for providing scientific basis for the assessment of genetic diversity and appropriate conservation strategies of tea landraces.