五个罗氏沼虾群体遗传多样性的微卫星分析

GENETIC DIVERSITY ANALYSIS OF FIVE POPULATIONS OF MACROBRACHIUM ROSENBERGII USING MICROSATELLITE MARKERS

利用16对微卫星标记对来自泰国(CP)、缅甸(MN)、孟加拉(BD)和中国(MP和DP)的共5个罗氏沼虾群体进行了遗传多样性和遗传结构的分析。结果显示,16个微卫星位点均具有较高的多态性,平均等位基因数(Na)、期望杂合度(He)、Shannon信息指数(I)和多态信息含量(PIC)分别为17.563、0.8316、2.1662和0.7328。5个群体的期望杂合度(He)介于0.7025—0.8594,多态信息含量(PIC)介于0.6538—0.8048,表明所有群体均具有高度遗传多样性,遗传多样性水平CP>MP>BD>MN>DP。遗传分化指数(Fst)值介于0.03430—0.17333,表明所有群体间均有不同程度的遗传分化。16个微卫星位点的Fst值均大于0.05,均值为0.0977,与群体间有遗传分化相符。AMOVA分析显示群体间变异占总变异的6.22%,群体内个体间的变异占总变异的40.72%,个体内部的遗传变异占总变异的53.07%。基于Nei氏遗传距离构建的UPGMA系统进化树显示,MN群体首先与MP群体聚为一类,再与DP群体聚为一类,之后再与BD群体聚为一类,最后与CP群体聚为一类,表明中国群体与泰国群体亲缘关系较远。遗传结构分析显示,参试样本被划分为5个理论群体,除MP群体中个体遗传结构混杂外,其余群体中个体遗传结构相对独立。研究为罗氏沼虾种质资源的开发利用和优良品种的选育提供了参考数据。

Genetic diversity and genetic structure of five populations of Macrobrachium rosenbergii from Thailand(CP),Myanmar(MN),Bangladesh(BD)and China(MP and DP)were analyzed with 16 polymorphic microsatellite markers.The results showed that 16 microsatellite sites had high polymorphism,with average allele number(Na),expected heterozygosity(He),Shannon information index(I)and polymorphic information content(PIC)at 17.563,0.8316,2.1662 and 0.733,respectively.The expected heterozygosity(He)of five populations was between 0.7025 and 0.8594,and the PIC was between 0.6538 and 0.8048,indicating that all populations had high genetic diversity.The level of genetic diversity was CP>MP>BD>MN>DP.The value of genetic differentiation index(Fst)was between 0.03430 and 0.17333,indicating different degrees of genetic differentiation among all populations.The Fst values of these 16 microsatellite sites were all greater than 0.05,with an average of 0.0977,which was consistent with the genetic differentiation among the populations.Molecular variation analysis(AMOVA)revealed that about 6.22%genetic variation was derived from inter-populations,40.72%variation was derived from intra-populations and 53.07%variation was derived from intra-individuals.The UPGMA phylogenetic tree based on Nei’s genetic distance showed that the MN population clustered with the MP population first,then with the DP population,then with the BD population,and finally with CP population,indicating that the Chinese populations were far from the Thailand populations.The genetic structure simulation analysis suggested that there were five logic populations in all samples.Except for the mixed genetic structure of individuals in the MP population,the genetic structure of individuals in the remaining populations was relatively independent.This study provides reference data for the development and utilization of the germplasm resources and the breeding of superior species of Macrobrachium rosenbergii.