贵州省5个金背鲤(Cyprinus carpio var.Jinbei)地理种群的遗传多样性与遗传结构分析

Genetic Diversity and Genetic Structure Analysis of Five Geographical Populations of Jinbei Common Carp(Cyprinus carpio var.Jinbei)in Guizhou Province

为探究稻田养殖金背鲤Cyprinus carpio var.Jinbei遗传多样性现状,采用线粒体DNA D-loop基因联合Cyt b基因测序分析方法,2020年8—10月分析评价了贵州省黎平县、从江县、锦屏县、都匀市和黄平县5个地理种群体质量379.4~431.8 g、体长22.51~24.90 cm金背鲤的遗传多样性、遗传结构及种群历史动态。结果显示,D-loop区共界定了21种单倍型,5个地理种群整体单倍型多样性指数(H_(d))和核苷酸多样性指数(P_(i))分别为0.672和0.00533。Cyt b基因共界定了28种单倍型,5个地理种群整体单倍型多样性指数(H_(d))和核苷酸多样性指数(P_(i))分别为0.805和0.00413。单倍型邻近系统树与单倍型网络图显示,金背鲤5个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,基于D-loop和Cyt b基因,遗传变异系数F_(st)分别为0.06871和0.13447,群体间变异分别占6.87%和13.45%,群体内变异分别占93.13%和86.55%。基因流N_(m)值显示,除黄平与黎平群体基因流N_(m)值无限大(Inf),锦屏、从江群体与黄平群体N_(m)>1外,其余种群间均N_(m)<1。5个地理种群中性检验结果均未出现显著负值,核苷酸错配图显示双峰或多峰。贵州省稻田金背鲤总体遗传多样性偏低,尤其锦屏群体遗传多样性匮乏,遗传变异主要发生在种群内部,各地理群体历史上未发生过种群扩张。建议加强贵州省金背鲤遗传资源保护,将分化程度不同的群体作为独立的管理单元,以开展针对性保护措施。

In order to explore current situation of resource diversity of Jinbei common carp Cyprinus carpio var.Jinbei cultured in rice field in Guizhou province,the genetic diversity,genetic structure and historical dynamics of the five geographical populations of Jinbei common carp with body weight of 379.4~431.8 g and body length of 22.51~24.90 cm in Liping County,Congjiang County,Jinping County,Duyun City and Huangping County were analyzed and evaluated from August to October in 2020 by using the sequence analysis methods of mitochondrial DNA D-loop gene and Cyt b gene.The results showed that 21 haplotypes were defined in the D-loop region,with overall haplotype diversity(H_(d))of 0.672 and nucleotide diversity index(P_(i))of 0.00533 in the 5 geographical populations.A total of 28 haplotypes were defined in the Cyt b gene,with overall haplotype diversity(H_(d))of 0.805 and nucleotide diversity index(P_(i))of 0.00413 in the 5 geographical populations.Haploheteroecious phylogenetic tree and haplotype network showed that there was no obvious pedigree structure and geographical structure among the five populations.AMOVA analysis results showed that the genetic variation coefficients F_(st) were 0.06871 on D-loop region,and 0.13447 on Cyt b gene,the inter-population variation accounted for 6.87% and 13.45%,the intra-population variation accounting for 93.13% and 86.55%,respectively.Gene flow N_(m) value showed that the N_(m) values of gene flow in Huangping and Liping populations were infinite(INF),N_(m) value greater than 1 in Jinping,Congjiang population and Huangping group in other populations being less than 1.The neutral test indicated that the five geographic populations did not show significant negative values,and the nucleotide mismatch diagram showed double peaks or multiple peaks.In this study,we found that the low.Overall genetic diversity was observed in Jinbei common carp in Guizhou rice field,especially,the Jinping population lacked genetic diversity,and genetic variation within the population,and no population expansion was found in the history of various geographic groups.The findings suggest to strengthen the protection of genetic resources of C.carpio var.Jinbei in Guizhou province,and to take the populations with different degrees of differentiation as independent management units to carry out targeted conservation measures.