基于SSR标记的大明松天然群体遗传多样性分析

Genetic diversity of Pinus taiwanensis var. damingshanensis natural populations by SSR markers

关键词:  大明松, 天然群体, 遗传多样性, 遗传分化, SSR分子标记

Key words:  Pinus taiwanensis var. damingshanensis, natural population, genetic diversity, genetic differentiation, SSR molecular marker

摘要:

大明松是广西和贵州特有的高山松类,具有很高的经济价值和生态价值,其自然种群长期没有得到充分的保护和利用,不利于该树种长期稳定发展。为了合理保护和开发利用大明松天然遗传资源,该文利用12个SSR分子标记对大明松3个天然群体进行遗传多样性研究,分析其群体间的遗传分化和基因流,为该物种的保护策略提供参考。研究结果表明:(1)12对引物共检测到37 个等位基因,多态位点百分率为100%。每个位点平均观察等位基因数(Na)为3.08,平均有效等位基因数(Ne)为1.68, 不同位点间有效等位基因数差异较大; 每个位点平均观察杂合度(Ho)为0.35,平均期望杂合度(He)为0.40,平均多态信息含量(PIC)为0.31。(2)3 个群体的Shannon's多样性指数变化范围为0.48～0.65,Nei's基因多样度的变化范围为0.27～0.39,与其他近缘种松类相比遗传多样性偏低。群体平均观察杂合度为0.40,平均期望杂合度为0.33,平均有效等位基因数为1.58。群体间基因分化系数(Gst)为0.10,群体间的遗传分化水平较低,大部分变异均存在群体内。群体间的基因流(Nm)为2.74,说明大明松群体间的基因交流比较充分。该研究可为大明松生物多样性保护提供重要参考依据,为科学利用大明松资源打下基础。

Abstract:

Pinus taiwanensis var. damingshanensis is a kind of endemic alpine pine of Guangxi and Guizhou, which has high economic and ecological values. Its natural population has not been fully protected and utilized for a long time, which is not conducive to long-term stable development of this species. In order to rationally protect and exploit the natural genetic resources of P. taiwanensis var. damingshanensis, 12 SSR markers were used to study the genetic diversity of three natural populations of P. taiwanensis var. damingshanensis, and to analyze the genetic differentiation and gene flow among populations, so as to provide reference for the protection strategy of this species. The results were as follows:(1)A total of 37 alleles were detected by 12 pairs of primers, and the percentage of polymorphic loci was 100%. For every site, the average number of observed alleles(Na)was 3.08, and the average number of effective alleles(Ne)was 1.68. The number of effective alleles varied greatly among different loci. The average observed heterozygosity(Ho)was 0.35, the average expected heterozygosity(He)was 0.40, and the average polymorphism information content(PIC)was 0.31 for every site.(2)The Shannon's information index of the three populations ranged from 0.48 to 0.65, and the Nei's gene diversity ranged from 0.27 to 0.39. Compared with other related species of pines, the genetic diversity was low. For each population, the average observed heterozygosity was 0.40, and the average expected heterozygosity was 0.33,the average number of effective alleles was 1.58. The genetic differentiation coefficient(Gst)among populations was 0.10. Most of the variation existed in the population and the genetic differentiation level among populations was low. The range of gene flow(Nm)was 2.74, indicating that gene exchange between populations is sufficient of P. taiwanensis var. damingshanensis. This study can provide an important reference for the protection of biodiversity, and lay a foundation for the scientific utilization of P. taiwanensis var. damingshanensis.