江西主要山脉野生蕙兰的遗传结构与分化

Genetic Diversity and Differentiation of Wild Cymbidium faberi Rolfe in the Main Mountain Range of Jiangxi Province

蕙兰为极具潜力的观赏以及香花植物资源,研究其遗传结构对蕙兰资源保护具有一定的指导意义。采用ISSR分子标记对江西省5个山脉分布的16个野生蕙兰(Cymbidium faberi Rolfe)居群和武夷山脉邵武市的1个居群进行遗传多样性与遗传结构研究,结果表明:12条引物共扩增得到142条谱带,其中多样性条带129条,多态性条带百分率为90.85%。POPGENE软件分析结果表明,蕙兰物种水平上的期望杂合度(He)为0.289 2,Shannon指数(I)为0.439 3,居群间的期望杂合度为(He)为0.188 6,Shannon指数(I)为0.286 5,总体遗传分化系数(FST)为0.348 1,基因流(Nm)为0.936 6,表明江西省分布的野生蕙兰资源在物种和居群的水平上均具有较高的遗传多样性。基于ISSR分子标记数据的UPGMA聚类和STRUCTURE群体遗传结构分析表明,蕙兰居群并没有呈现出按照山脉分布的特点,各山脉间蕙兰居群基因交流有限,17个蕙兰群体最有可能来自3个基因库。

Cymbidium faberi Rolfe is a kind of potential ornamental and aromatic flower resources,and investi-gating its genetic structure provide guiding significance for the protection of wild C.faberi Rolfe resources.Using ISSR molecular markers to study the genetic structure of 16 wild C.faberi Rolfe populations in 5 mountains of Jiangxi Province and the Shaowu population in Wuyi mountain.The results showed that 12 primers total 142 bands were amplified,of which 129 were diverse bands,and the percentage of polymorphic bands was 90.85%.POPGENE analysis show that the Nei's gene diversity(He)was 0.2892,and the Shannon index(I)was 0.4393 at the species levels,the Nei's gene diversity(He)was 0.1886,and the Shannon index(I)was 0.2865 among the populations.The genetic differentiation coefficient(Fsr)was 0.3481,gene flow(Nm)was 0.9366,these indicated that the wild C.faberi Rolfe resources have high genetic diversity at the species and population levels.UPGMA clustering and STRUCTURE population genetic structure analysis showed no correlation with the distribution of C.faberi Rolfe populations according to the mountains.The gene exchanges of the C.faberi Rolfe populations among the mountains were limited,and the 17 C.faberi Rolfe populations were the most likely from three gene banks.