云南南涧县古茶树资源遗传多样性的EST-SSR分析

EST-SSR Analysis of Genetic Diversity of Ancient Tea Tree Resources in Nanjian County, Yunnan Province

摘要:

为探究栽培型古茶树阿萨姆茶(Camellia sinensis var. assamica)种质资源的遗传多样性，采用EST-SSR分子标记技术对云南南涧县无量山镇古茶园64份种质资源进行遗传多样性和遗传结构分析。结果表明, 20对引物共检测出223个等位基因，群体间平均有效等位基因数为3.48个；观测等位基因数(N_a)为6.25；有效等位基因数(N_e)为2.983；Shannon多样性指数(I)为1.251；Nei基因多样性指数(H)为0.646。POPGENE分析表明遗传分化系数(F_st)为0.063，居群间存在中度分化，基因流(N_m)为3.710。AMOVA分子方差分析表明，阿萨姆茶的遗传变异14%发生在居群间，86%发生在居群内，说明阿萨姆茶居群遗传变异主要发生在居群内部，且基因交流丰富。南涧县古茶园古茶树居群的遗传多样性丰富，这为阿萨姆茶种质资源的保护利用和新品种选育提供了科学依据。

Abstract:

To explore the genetic diversity of cultivated ancient tea tree (Camellia sinensis var. assamica) germplasm resources, the genetic diversity and structure of 64 germplasm resources in the ancient tea garden of Wuliangshan Town, Nanjian County were analyzed by using EST-SSR molecular markers. The results showed that a total of 223 alleles were detected with 20 pairs of primers, and the average effective number of alleles among populations was 3.48. The average observed allele (N_a), average effective allele (N_e), average Shannon diversity index (I), and average of Nei’s gene diversity index (H) were 6.25, 2.983, 1.251 and 0.646, respectively. POPGENE analysis showed that the mean genetic differentiation coefficient (F_st) was 0.063, indicating that there was moderate differentiation among populations with gene flow (N_m) of 3.710. AMOVA molecular variance analysis showed that 14% of genetic variation in C. sinensis var. assamica occurred among populations and 86% occurred within population, indicating that genetic variation in C. sinensis var. assamica mainly occurred within population and genetic exchange was abundant. The rich genetic diversity of the ancient tea tree population in the ancient tea garden of Nanjian County would provide a scientific basis for the protection and utilization of C. sinensis var. assamica germplasm resources and the selection of new varieties.