基于EST-SSR分子标记的广西海伦兜兰遗传多样性研究

Genetic Diversity of Paphiopedilum helenae in Guangxi based on EST-SSR Markers

关键词:  海伦兜兰  EST-SSR  分子标记  遗传多样性  遗传结构

Key words:  Paphiopedilum helenae  EST-SSR  molecular marker  genetic diversity  genetic structure

摘要:

海伦兜兰（Paphiopedilum helenae）具有极高的观赏价值，为国家一级重点保护野生植物。本研究利用EST-SSR分子标记技术对广西海伦兜兰的5个居群（71个样品）的遗传多样性和遗传结构进行分析，旨在为该种质资源的有效保护与利用提供参考依据。结果表明：海伦兜兰具有中等遗传多样性，多态位点百分比（PPB）为90%-100%，期望杂合度（H_e）平均值为0.451，香农信息指数（I）平均值为0.801。海伦兜兰绝大多数（93%）遗传变异存在于居群内，仅有7%遗传变异存在于居群间，居群内的遗传变异大于居群间的变异，基因流（N_m）平均值为4.916。非加权组平均法（UPGMA）、主坐标分析（PCoA）和Structure分析结果表明，聚类并未严格按照地理位置划分，广西邦亮长臂猿国家级自然保护区靖西市（JX）和龙州县下冻镇春秀村（LZ）居群的遗传多样性较高，应作为海伦兜兰重点保护单元进行保护。

Abstract:

Paphiopedilum helenae has extremely high ornamental value and is a national first-class key protected wild plant.In this study, EST-SSR molecular markers were used to analyze the genetic diversity and genetic structure of 71 samples from 5 populations of P.helenae in Guangxi, in order to provide an important reference for the effective protection and utilization of the germplasm resources.The results showed that P.helenae has moderate genetic diversity, with a percentage of polymorphic loci (PPB) ranging from 90% to 100%, the average expected heterozygosity (H_e) was 0.451, and the average Shannon information index (I) was 0.801.The vast majority (93%) of genetic variation exists within populations, with only 7% occurring between populations.The genetic variation within populations is greater than that between populations, and the estimated gene flow (N_m) average value was 4.916.Unweighted Pair Group Method with Arithmetic (UPGMA), Principal Coordinate Analysis (PCoA) and Structure analysis showed that clustering was not strictly based on geographical location.The genetic diversity of Bangliang Gibbon Nature Reserve Jingxi County (JX) and Xialeng Town, Longzhou County (LZ) populations is relatively high, and should be protected as a key unit for P.helenae.