贵州7个鲤养殖群体遗传多样性与遗传结构分析

Analysis of genetic diversity and genetic structure of 7 cultured Cyprinus carpio populations in Guizhou Province

为探究贵州鲤(Cyprinus carpio)养殖群体遗传多样性与遗传分化现状,基于线粒体DNA Cyt b基因,采用PCR扩增与直接测序法,对贵州7个鲤养殖群体进行了遗传多样性及遗传结构分析。结果显示,152尾个体共界定了16种单倍型,7个养殖群体整体单倍型多样性指数(H_(d))、核苷酸多样性指数(P_(i))分别为0.792、0.00323。单倍型网络图(network)显示,7个养殖群体间没有形成明显的谱系结构和地理结构。AMOVA分析结果显示,群体间和群体内变异占比分别为41.63039%和58.36961%,遗传分化指数(Fst)为0.41630,达到极显著差异水平(P<0.0001)。基因流(N_(m))值显示,除松浦镜鲤与松浦红镜鲤群体、金背鲤与建鲤群体N_(m)值分别为2.238、4.805外,其余群体间N_(m)值均小于1.000。7个养殖群体中性检验Fu’s F_(s)、Tajima’s D结果均未出现显著负值。结果表明,贵州7个鲤养殖群体总体核苷酸多样性指数偏低,其中,松浦镜鲤、松浦红镜鲤、福瑞鲤核苷酸多样性指数极低;7个鲤养殖群体总体遗传分化程度较高;各群体遗传变异主要发生在群体内部,遗传多样性有待提高。

In order to explore the current status of genetic diversity and genetic differentiation of 7 cultured Cyprinus carpio populations in Guizhou Province,PCR amplification and direct sequencing were used to analyze the genetic diversity and genetic structure of 7 cultured C.carpio populations in Guizhou Province based on the mitochondrial DNA Cyt b gene.The results showed that 152 individuals defined 16 haplotypes,and the overall haplotype diversity index(H_(d))and nucleotide diversity index(P_(i))of the 7 cultured C.carpio populations were 0.792 and 0.00323,respectively.The haplotype network diagram showed that there was no obvious pedigree structure or geographic structure among 7 cultured populations.The results of AMOVA analysis showed that inter-population and intra-population variation accounted for 41.63039%and 58.36961%,respectively,and the genetic coefficient of variation Fst was 0.41630,reaching a very significant level(P<0.0001).Except for that the gene flow(N_(m))values of Cyprinus carpio Songpu population and Cyprinus carpio Songpu red mirror population,Cyprinus carpio var.Jinbei population and Cyprinus carpio var.Jian population were 2.238 and 4.805 respectively,N_(m)values between the other populations were all less than 1.000.The neutral tests Fu’s F_(s) and Tajima’s D results for 7 cultured populations showed no significant negative values.The results showed that the overall nucleotide diversity index was low in 7 cultured populations,of which the nucleotide diversity indexes of Cyprinus carpio Songpu red mirror,Cyprinus carpio Songpu and Cyprinus carpio,FFRC strain common carp were very low.The overall genetic differentiation of 7 cultured populations was high.The genetic variation of each population mainly occurred within the population,and the genetic diversity needed to be improved.