菲律宾蛤仔大连群体不同世代的遗传多样性  

Genetic diversity of different generations of the Dalian population of Manila clam Ruditapes philippinarum through selective breeding

作　　者：虞志飞[1] 闫喜武[1] 杨霏[1] 王金海[1] 张跃环[1] 杨凤[1] 张国范[2] 

机构地区：[1]大连海洋大学生命科学与技术学院,辽宁大连116023 [2]中国科学院海洋研究所,山东青岛266071

出　　处：《生态学报》2011年第15期4199-4206,共8页Acta Ecologica Sinica

基　　金：现代农业产业技术体系建设专项资金资助(CARS-48)

摘　　要：采用12对有效微卫星引物对大连群体菲律宾蛤仔连续4个选育世代(F1、F2、F3、F4)的144个个体进行了遗传多样性分析。结果表明:共获121个等位基因,每个位点的等位基因数在2—6个不等,其大小在101—273 bp之间;各个世代平均等位基因数在3.75—4.58,平均观测杂合度在0.3391—0.3860之间。从F-检验结果上看,所有世代内有2个位点遗传分化较弱,8个位点遗传分化中等,2个位点遗传分化较大;配对比较Fst值(0.05—0.15)表明4个世代群体间遗传分化程度中等。Fis值表明有2个世代位点杂合度处于过剩状态;但对连续4个世代而言,每个世代均表现出一定程度的杂合子缺失。随着世代连续选育的进行,Nei氏遗传相似性逐渐减小(0.8203-0.8107-0.8031);遗传距离逐渐增大(0.1918-0.2099-0.2129);不同世代群体间遗传相似性系数为0.7873—0.8685,遗传距离为0.141—0.2391。4个世代平均PIC值为0.5055,表明选育后代遗传多样性较好,还有较大的选育潜力,可以继续进行上选。The present study examined the genetic structure and variation among different generations of Manila clam Ruditapes philippinarum obtained through selective breeding by using 12 microsatellite markers.Four consecutive generations（F1,F2,F3,and F4） were selected with 10% selection intensity from a wild population from Shihe,Dalian（Liaoning Province,China）.Thirty six individuals were sampled from each generation.Among the 12 microsatellite loci,121 alleles were detected.The number of alleles on each locus varied from 2 to 6 and the allele size ranged from 101 to 273 bp.Each generation had average effective alleles of 3.75-4.58 and average observed heterozygosity of 0.3391-0.3860.Based on P values of genotypes,all four generations deviated from the Hardy-Weinberg equilibrium with varying degrees.Of the 48 generation × locus combinations（4 generations × 12 loci）,27 of which were not in an equilibrium state.Except the locus Asari24,all polymorphic loci had positive inbreeding coefficients（Fis）,indicating that high degree of inbreeding existed in all four generations.The inter-generation fixation indices（Fst） varied from 0.0338 to 0.2136 and there was significant genetic differentiation among the 12 polymorphic loci.The F-statistics showed that among all generations two loci had weak genetic differentiation,eight loci had moderate,and the remaining two loci had high genetic differentiation.Pairwise Fst values ranged from 0.05 to 0.15,which also indicated that the clam had moderate genetic differentiation among the generations.Based on the Fis values,two out of four generations exhibited heterozygote excess,but all the generations in sequence showed some degree of heterozygote deficiency.The Nei′s genetic similarity decreased（0.8203→0.8107→0.8031） and genetic distance increased（0.1918→0.2099→0.2129） from one generation to the next through selective breeding.The genetic similarity coefficients among the different generations ranged from 0.7873 to 0.8685,and genetic distance varied f

关 键 词：菲律宾蛤仔 微卫星 遗传多样性 遗传分化 

分 类 号：S917.4[农业科学—水产科学]