海南岛鸟巢蕨自然种群遗传多样性SRAP分析

Analysis of Population Genetic Diversity of Wild Asplenium nidus in Hainan Island Based on SRAP Markers

为揭示鸟巢蕨(Asplenium nidus)自然种群的遗传多样性和亲缘关系,促进野生鸟巢蕨资源有效保护和利用,本研究以海南岛保护区自然分布的鸟巢蕨为对象,利用SRAP分子标记技术,采用UPGMA方法对海南岛6个种群96份鸟巢蕨样本进行聚类分析。结果表明:(1)鸟巢蕨10对引物共扩增出184个位点,其中多态位点174个,多态位点百分率为94.57%,各种群间的多态位点百分比(PPB)存在较大差异,SRAP检测到的种群平均多态位点百分比为85.15%。鸟巢蕨种群间遗传变异程度范围较大,各种群均具有较高遗传多样性水平。(2)种群内部遗传分化发生比例为86.94%,而种群间遗传分化发生比例为13.06%,证明种群间存在一定水平遗传分化。(3)鸟巢蕨6个种群平均遗传相似度为0.9224,平均遗传距离为0.0809。其中,BW和EXL遗传距离最近,LMS2和LMS3遗传距离最远,分别为0.0508和0.1166。鸟巢蕨野外种群遗传距离UPGMA聚类分析结果显示,地理位置较近的BW和EXL聚类在一起,说明两者间基因流动通畅;同一地区LMS1和LMS3聚类在一起;而黎母山地区LMS2与其余种群遗传距离最大,遗传分化最显著,说明SRAP标记在鸟巢蕨种群间具有丰富多态性,该结果对揭示鸟巢蕨亲缘关系具有重要意义,为保护工作提供了指导。由于鸟巢蕨野外生境受到不同程度破坏,建议就地保护为主,在种群遗传多样性较高区域——黎母山区域建立级别更高的自然保护区,即尽快建成热带雨林国家公园,这有利于鸟巢蕨自然生境和种群恢复与扩大,促进热带雨林保育和物种多样性可持续发展。

Asplenium nidus,commonly called bird’s nest fern,now unique in the rainforest,is referred to as a“Hanging Garden”plant.In order to reveal the genetic diversity and genetic relationship of the natural population of A.nidus,and promote the effective conservation and utilization of wild A.nidus resources,96 samples were collected from 6 populations of A.nidus in Hainan Island,and clustered by using UPGMA cluster analysis based on SRAP markers.The results showed that a total of 184 loci were amplified by 10 pairs of primers in A.nidus,of which 174 were polymorphic loci with the percentage of polymorphic loci or bands(PPB)being 94.57%.The PPB varied greatly in the populations,with an average of 85.15%based on SRAP markers.The populations of A.nidus had a relatively higher genetic variation,and each population had a high level of genetic diversity.POPGENE analysis showed that the percentage of genetic differentiation within the population was 86.94%,while the percentage of genetic differentiation between populations was 13.06%,which proved that there was a certain level of genetic differentiation among the populations.The average genetic similarity of the 6 populations of A nidus was 0.9224,and the average genetic distance was 0.0809.The genetic distance of the populations between BW and EXL was the closest,which was 0.0508,and the genetic distance between LMS2 and LMS3 was the longest,which was 0.1166.UPGMA cluster analysis showed the genetic distance of the wild populations of A.nidus in BW and EXL are geographically close,and hence were clustered together,indicating that the gene flow of A nidus in these two locations was smooth.The A nidus populations in LMS1 and LMS3 in the same area were clustered together.The genetic distance between the population in LMS2 and other populations in LiMushan area was the highest,and the genetic differentiation was also the most significant.This shows that SRAP markers have abundant polymorphisms among the populations of A nidus and are of great significance for revealing the genetic relationship of A nidus.When compared with the wild habitat,the population of A.nidus in each area was found to be damaged to different degrees.It is recommended to focus on in-situ conservation of A nidus.The LMS3 area,where the genetic diversity of the A nidus population is higher,can be selected to establish a higher-level nature reserve or Hainan tropical rainforest national park to facilitate expansion and rehabilitation of the population and habitat of A nidus for conservation of tropical rainforest and sustainable development of plant diversity.