基于线粒体DNA控制区序列的黑鲷亲鱼、放流及海捕群体遗传多样性比较分析

Comparative Analyses of Genetic Diversity of Broodstock,Hatchery-Released and Captured Populations of Acanthopagrus schlegelii Based on the Mitochondrial DNA Control Region Sequence

为了解黑鲷(Acanthopayrus schlegelii)种质资源现状以及放流群体可能对野生群体产生的遗传学影响,本研究采用线粒体DNA控制区序列对采自舟山、莱州和南通的黑鲷亲鱼、放流群体和海捕群体进行了遗传学比较研究。研究显示:764尾黑鲷个体共检测到69个单倍型,其中亲鱼群体与放流群体的共享单倍型为5个、亲鱼群体与海捕群体的共享单倍型为6个,放流群体与海捕群体的共享单倍型为27个。亲鱼群体、放流群体和海捕群体的单倍型多样度分别为0.849,0.786~0.935和0.850~0.951,核苷酸多样度分别为0.011,0.005~0.009和0.008~0.009。群体间遗传分化指数F_(ST)显示,黑鲷亲鱼群体与放流群体、放流群体间以及放流群体与海捕群体均产生中等程度的遗传分化。研究结果表明,黑鲷亲鱼群体、放流群体以及海捕群体的遗传多样性均较高,说明放流群体的种质资源良好,但黑鲷苗种与海捕群体间存在较大的遗传分化,仍需开展其遗传多样性监测工作,以保护黑鲷的优质种质资源。

In order to understand the current situation of Acanthopagrus schlegelii germplasm resource and the possible genetic effect of hatchery-released populations on wild populations during stock enhancement,we used mitochondrial DNA control region sequence variation to compare and analyze the genetic difference among broodstock,hatchery-released populations and captured populations of A.schlegelii collected from Zhoushan,Laizhou and Nantong.The results showed that 69 haplotypes were detected among 764 individuals,including 7 haplotypes in broodstock,46 in hatchery-released population and 49 in captured population.Among these haplotypes,5 were shared between broodstock and hatchery-released population,6 were shared by captured population,and 27 were shared between hatchery-released and captured populations.The haplotype diversity was 0.849,0.786~0.935 and 0.850~0.951 in broodstock,hatchery-released population and captured population,and the nucleotide diversity was 0.011,0.005~0.009 and 0.008~0.009,respectively.The inter population genetic differentiation index F_(ST) showed that there was a moderate degree of genetic differentiation among hatchery-released populations,between hatchery-released population and broodstock,and between hatchery-released and captured populations,and there was no significant genetic differentiation among captured populations.The network diagram based on the haplotype of mitochondrial DNA control region of A.schlegelii showed that there was no obvious pedigree structure.AMOVA analysis showed that the genetic variation mainly existed within population.Based on the above results,long-term stock enhancement may have a certain impact on the wild population of A.schlegelii.In future stock enhancement,we should pay attentions to the number and source of broodstock,select broodstock with high genetic diversity,narrow the genetic gap between hatchery-released and wild populations,reduce the impact on wild populations,protect the germplasm resources of A.schlegelii,and realize the sustainable utilization of resources.