千岛湖片段化景观中蟋蟀种群遗传多样性和遗传结构研究

发布时间：2018-04-13 04:05

本文选题：千岛湖 + 景观片段化　；参考：《浙江农林大学》2015年硕士论文

【摘要】：千岛湖是典型的由水库修建而形成的片段化景观,由于水位的上升而形成了众多的路桥岛屿。随着栖息地的破坏和隔离的加剧,分布在千岛湖岛屿上的昆虫种群的多样性也会受到改变。本文通过2014年8月到9月对千岛湖岛屿的昆虫采样,基于千岛湖10个岛屿上的小棺头蟋种群遗传多样性和遗传结构研究,结果发现:通过对线粒体DNA COI基因片段的研究,在10个种群中检测到了共18个单倍体型,通过遗传多样性的研究发现,10个种群都保持了较高的遗传多样性水平,单倍体型多样性在0.7636到0.9451之间,通过回归分析发现岛屿面积与遗传多样性的大小存在着显著的相关性(p0.001),而其他的岛屿属性对遗传多样性的影响不大;通过Tajima’s中性检验可以发现,大部分岛屿的Tajima’s D值都是正数,基本的岛屿在近期内都经历了瓶效应;10个种群之间的两两遗传分化研究表明,遗传系数Gst在-0.05873~0.29588之间,大于0.05即出现了中等程度分化的占总数的28.9%,在0~0.05即没有出现遗传分化占总数的71.1%。种群总的基因流在4.76;各个种群两两间的基因流分布从1.80340到43.24453;基因流Nm大于4占总数的53.3%,小于4而大于1的两两种群对占总数的46.7%,没有出现Nm在1以下的两两种群;通过mantel检验发现,隔离距离和遗传分化系数以及遗传距离之间有极显著的相关性,P值都小于0.001,种群间的遗传分化和基因流基本符合BID模式和踏脚石模式;通过空间分子方差分析(SAMOVA),对10个种群进行分类,可以发现分类中有显著的区域性,地理分布相似的岛屿表现在遗传结构上表现出了更大的相似性。
[Abstract]:Qiandao Lake is a typical fragmented landscape formed by reservoir construction.With habitat destruction and isolation increasing, the diversity of insect populations on the Qiandao Lake islands will be changed.From August to September, 2014, the insect samples from Qiandao Lake were collected, and the genetic diversity and genetic structure of the population were studied based on the 10 islands in Qiandao Lake. The results showed that: the mitochondrial DNA COI gene fragment was studied.A total of 18 haploid types were detected in 10 populations. The results of genetic diversity analysis showed that all the 10 populations maintained a high level of genetic diversity, and the haploid diversity ranged from 0.7636 to 0.9451.It was found by regression analysis that there was a significant correlation between island area and the size of genetic diversity, while other island attributes had little effect on genetic diversity.The Tajima's D value of most islands is positive, and the basic islands have experienced bottle effect in the near future. The genetic coefficient Gst is between -0.05873 and 0.29588.When the differentiation is greater than 0.05, the proportion of moderate differentiation is 28.9. in 00.05, there is no genetic differentiation, which accounts for 71.1% of the total.The total gene flow of each population is 4.76, the distribution of gene flow between two populations ranges from 1.80340 to 43.24453.The gene flow N m > 4 accounts for 53.3% of the total, and the number of two species less than 4 but greater than 1 accounts for 46.7% of the total, and there are no two species with Nm below 1.The results of mantel test showed that there was a significant correlation between segregation distance, genetic differentiation coefficient and genetic distance (P < 0.001), and genetic differentiation and gene flow between populations were basically in accordance with BID model and stepping stone model.Through the analysis of spatial molecular variance, 10 populations were classified. It was found that there were significant regional features in the classification, and the islands with similar geographical distribution showed greater similarity in genetic structure.
【学位授予单位】：浙江农林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：Q963

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