中国明对虾人工选育群体与野生群体遗传多样性的SSR分析

SSR Analysis on Genetic Diversity in Breeding and Wild Populations of Fenneropenaeus chinensis

利用微卫星标记技术分析了中国明对虾(Fenneropenaeus chinensis)野生群体(Wild Population,WP)和"黄海2号"第10代选育群体(Breeding Population,BP)的遗传多样性,以检测累代人工选育对中国明对虾群体遗传结构的影响。结果显示,15个微卫星位点共检测到462个等位基因,微卫星位点等位基因数(N_a)和有效等位基因数(N_e)分别为3~44个和2~29个,多态信息含量(PIC)为0.518~0.964。野生群体和选育群体的平均观测杂合度分别为0.852和0.810,15个微卫星位点的等位基因频率在2个群体发生了显著的变化。通过计算P值确定位点Hardy-Weinberg平衡偏离情况,Fis结果显示,共有11个群体位点表现为杂合子过剩,Shannon指数(H)分别为2.786和2.399。2个群体的N_ei′s无偏遗传距离(u D)和无偏遗传相似度(u I)分别为0.177和0.838,遗传分化指数为0.017(P=0.001),表明群体发生了弱遗传分化。遗传变异来源分析显示,只有7.50%的变异来自于群体间,其余遗传变异均来自于个体间。结果表明,人工选育的中国明对虾"黄海2号"第10代群体具有较高的遗传多样性,仍具有很大的选育潜力,可以继续作为选育材料。

Studies were conducted for further understanding the level of genetic diversity and population genetic structure of Fenneropenaeus chinensis under artificial breeding conditions.Fifteen fluorescence labeled microsatellite primers were used to analyze the genetic diversity and genetic differentiation in wild population(WP)and breeding population(BP)of F.chinensis.The wild population was collected from the western coast of Korean Peninsula(34°30?N,127°30?E),and the breeding population was obtained after selection for successive ten generations.In each population,40 samples were used for DNA extraction according to the protocol provided by the manufacturer.PCR was performed in a 25μl reaction and the PCR products were sequenced by Sangon Biotech(Shanghai)Co.,Led.Allele data was analyzed by Cervus 3.0.7 and GenALEx 6.502.The results showed that a total of 462 alleles were identified at 15 microsatellite loci,the numbers of alleles(Na)and effective alleles(Ne)were 3~44 and 2~29 in WP and BP,respectively.The polymorphism information content(PIC)ranged from 0.518 to 0.964,and the observed heterozygosity(Ho)values of WP and BP were 0.518 and 0.964,respectively.P-values were calculated to confirm whether the 15 loci deviated from the Hardy-Weinberg equilibrium or not.Of the 30 population loci,there were 11 population loci was heterozygote excess.The Shannon genetic diversity index(H)in WP and BP were 2.786 and 2.399,respectively.The Nei’s unbiased genetic Distance(uD),as well as unbiased genetic Identity(uI)was 0.17 and 0.838,respectively.The Gene Flow(Nm)and Fst value of the two populations were 17.997 and 0.017(P=0.001),respectively,indicating that there was a low genetic differentiation.Partitioning of the genetic variation revealed that only 7.50%of the genetic variation was among the populations,and the other genetic variation was within the populations.This study showed that the‘Huanghai No.2’still has high genetic diversity after selection for successive ten generations,and it also has potential value for further breeding materials.