基于细胞色素b基因的鱇浪白鱼野生群体和养殖群体遗传多样性分析

Mitochondrial cytochrome b gene sequence diversity in wild and cultured populations of Anabarilius grahami

为探讨鱇浪白鱼野生群体和养殖群体的遗传多样性,测定了野生群体和养殖群体共29尾鱇浪白鱼的线粒体DNA细胞色素b基因的全序列。结果显示:在所有个体1 140 bp序列中检测到31个变异位点,其中28个转换位点,3个颠换位点,发现21种单倍型。养殖群体的核苷酸多样性指数(0.003 38)和单倍型多样性指数(0.980 95)高于野生群体核苷酸多样性指数(0.003 21)和单倍型多样性指数(0.934 07)。野生群体和养殖群体内的遗传距离分别为0.003 39和0.003 43,群体间的遗传距离(0.003 64)略大于群体内遗传距离。分子变异分析(AMOVA)结果显示:Fst=0.064 1(P<0.01),即6.41%的变异来自群体间,93.59%的变异来自群体内,变异大多发生在群体内,野生群体和养殖群体间未发生显著的遗传分化。2个群体Taji ma’sD检验、Fu和Li’sD与F检验均为负值,表明2个群体的检验结果均偏离中性模式,鱇浪白鱼群体可能受到群体扩张和自然选择的作用。

Genetic diversity of a wild population and a cultured population from Anabarilius grahami was measured based on cytochrome b gene of the mitochondrial.Fourteen and fifteen unrelated individuals were chosen in wild and cultured populations,respectively.Twenty-one haplotypes were identified.The cultured population exhibited higher average nucleotide diversity （π） and haplotype diversity （Hd） than the wild population.The genetic distances of the wild and the cultured populations were 0.003 39 and 0.003 43,respectively.The distance of inter-population （0.003 64） was larger than that of intra-population.AMOVA analysis demonstrated that Fst was 0.064 1（P〈0.01）.Small variance occurred between the two populations （6.41%） and large part of the variance occurred within populations （93.59%）.It implied that genetic variance mainly existed among intra-populations.No significant genetic differentiation was observed between the wild and cultured populations.The values from Tajima’s D,Fu and Li’s D and F of neutrality tests were all negative.It suggested that the test results of two A.grahami populations departured from neutrality model,which indicated that populations of A.grahami were possibly experienced population expansion and natural selection.