Genetic Diversity of Thunnus thynnus and Thunnus albacares Stocks by AFLP

利用选择性扩增片断长度多态性分子标记技术(AMPlIfIEd frAgMEnT lEngTH POlyMOrPHISM,AflP),分析了采自日本九州海域蓝鳍金枪鱼(THunnuS THynnuS)和台湾海域黄鳍金枪鱼(THunnuS AlbACArES)野生群体的遗传多样性水平.结果表明:9对选择性引物在2种金枪鱼中共扩增出675个位点(100--750 bP),其中蓝鳍金枪鱼和黄鳍金枪鱼多态位点分别为388个和368个.蓝鳍金枪鱼和黄鳍金枪鱼的多态位点比例、SHAnnOn遗传多样性指数分别为57.48%和54.52%,0.330 1和0.301 8.AMOVA分子方差分析显示:种间遗传分化中,83.79%的遗传变异由种间贡献,而16.21%的变异分布于种内个体之间.同其他鱼类比较,2种金枪鱼显示了较为丰富的遗传多样性水平,其种质资源处于较好的水平.研究结果将为我国蓝鳍金枪鱼和黄鳍金枪鱼的资源保护与合理利用提供重要的理论依据.Thunnus is a important commercially marine fish species,which is widely distributed.Thunnus has been intensively studied in China,including its basic biological characteristics in fishery and artificial reproduction.However,very few studies on Thunnus were focused on genetic diversity,which has become an obstacle to further researches on the protection,management,rational exploitation and sustainable utilization of Thunnus resources.The genetic diversity of wild Pacific blue-fin tuna(Thunnus thynnus)and Pacific yellow-fin tuna(Thunnus albacare)were investigated by using amplified fragment length polymorphic(AFLP) in the present paper.AFLP fingerprinting was regarded as one of the most useful techniques in nowadays for DNA fingerprint analysis.The results showed that a total of 675 DNA amplification bands ranging from 100--750 bp were produced using 9 pairs of primer combinations,and 35--54 polymorphic loci were detected per primer combination.The percentage of polymorphic loci and Shannon's information index of the blue-fin and yellow-fin tuna were 57.48%,0.330 1 and 54.52%,0.301 8,respectively.Both populations were at the same high level of genetic diversity.AMOVA analysis(83.79%) indicated that a certain extent of differentiation in two species.There were 83.79% of variance was among the populations and 16.21% of variance was within a population.Compared with other fishes,both tuna species possessed rich population genetic diversities.The information of genetic diversities in different populations will give us theoretical guidance in breeding and genetic improvement.福建省科技重大专项(2004NZ03)资