【摘要】 对2009年和2011年采自荣成湾的孔鳐(Raja porosa)群体共54尾鱼的线粒体DNA细胞色素b基因(cytb)部分序列进行测定,以分析其遗传多样性和群体遗传结构。结果显示,在所获得的782 bp序列中,共检测到11个单倍型、15个多态位点,其单倍型多样性指数(H)为0.498±0.081,核苷酸多样性指数(π)为0.0018±0.0005,遗传多样性水平较低。其中,2009年样品检测到3种单倍型、4个单一变异位点,其H和π值分别为0.378±0.181和0.0010±0.0006;2011年样品检测到9种单倍型、6个单一变异位点和6个简约信息位点,其H和π值分别为0.352±0.086和0.0020±0.0006。分子方差分析(AMOVA)分析显示它们的遗传变异主要集中在同年度个体间(98.22%),而不同年度个体间的遗传变异远远小于同年度内个体间的变异。Kimura’s 2-parameter模型分析得到的2009,2011年度孔鳐间的遗传距离为0.0013,遗传分化系数为0.01778,也表明2009年和2011年孔鳐的遗传分化程度低,没有明显的遗传变异。中性检验表明,荣成湾孔鳐群体可能发生过种群扩张。更多还原

【Abstract】 In this study,a 782bp fragment of mitochondrial DNA cytochrome b gene(cytb) from 54 Raja porosa individuals collected from the Rongcheng Bay in 2009 and 2011 were sequenced.A total of 15 polymorphic sites were detected,which defined 11 mitochondrial haplotypes.The haplotype diversity,nucleotide diversity were 0.498±0.081 and 0.0018±0.0005,respectively,indicating a lower genetic diversity in the stock.The results also showed that there are 4 singleton variable sites defined 3 haplotypes in 2009 group,and 6 singleton variable sites and 6 parsimony informative sites defined 9 haplotypes in 2011 group.The haplotype diverisity parameters in 2009 and 2011 groups were 0.378±0.181 and 0.532±0.086,respectively,and their nucleotide diversity parameters were 0.0010±0.0006 and 0.0020±0.0006,respectively.Analysis of Molecular Variance(AMOVA) indicated 98.22% genetic variation occurred within the same year.Genetic distance between these two groups calculated with the Kimura’s 2-parameter model is 0.0013,and the genetic differentiation value between the two groups is 0.01778,which all showed that there is nearly no genetic differentiation between the two groups.Neutrality test suggested that a population expansion might have happened before.更多还原