【摘要】 分析了不同时期引入到我国的4个繁育历史清晰、未发生种质混杂的海湾扇贝养殖群体成体的壳形态指标和群体遗传结构。壳表型参数分析表明,海湾扇贝北部亚种(Northernbay scallop,Argopecten irradians irradians)的浙江养殖群体(ZJ)、加拿大新布朗斯威克群体(NB)、马萨诸塞-弗吉尼亚混合群体(M-V)及海湾扇贝南部亚种(Southern bay scallop,Arg-opecten irradians concentricus)的北卡罗来那群体(NC)等不同群体间在壳形态方面存在显著差异南部亚种的NC群体壳高与壳长基本相等[壳高与壳长的比值(H/L)达0.99,壳型宽壳宽和壳长的比值(W/L)达到0.59];而北部亚种3个群体的壳长均大于壳高,其中ZJ和NB群体的壳形态尤其偏长,其H/L分别是0.92和0.90,NB群体的壳宽显著小于其他群体,W/L仅为0.36。RAPD分析结果表明,ZJ、NB、M-V、NC群体的多态位点比例分别为31.82%、29.55%、28.79%和31.82%,平均杂合度分别为0.1078、0.1134、0.0966和0.1197,表明在我国独立繁育了19代的ZJ养殖群体仍然保持了与其他群体相近的遗传多样性水平。4个群体间的遗传分化系数(Gst)为0.1892,表明其中18.92%的变异来自不同群体间的遗传差异,说明4个群体在遗传上存在着较大的分化。从遗传距离分析,ZJ与NB较近,两者间的遗传距离为0.0319,而两者与M-V间的遗传距离相对较远,分别为0.0442和0.0524;NC与M-V间的遗传距离为0.0368。这些结果表明,从原产地引种到国外时间较早的ZJ、NB等2个群体与较晚引进我国的M-V群体之间的遗传距离已超过了M-V群体(北部亚种)与NC群体(南部亚种)之间的遗传距离,说明独立繁育了近20代后,ZJ群体和NB群体均已产生了较大的遗传分化,这种分化可能有利于海湾扇贝的品种培育。更多还原

【Abstract】 Morphology and population genetics were analyzed in the offspring of four transplanted bay scallop (Argopecten irradians) populations including the North Carolina population (NC) of the southern subspecies (A.irradians concentricus), and the Zhejiang population (ZJ), the New Brunswick population (NB), and the Massachusetts-Virginia population (M-V) of the northern subspecies (A.irradians irradians).Significant differences in shell morphological indices exist among the four populations.The analyses indicated that the shell height in the southern subspecies is close to its shell length, while in the northern species populations the shell length is larger than its shell height.Random Amplification of Polymorphic DNA (RAPD) analyses with 20 random primers revealed 132 bands ranging from 230 to 2800 bp.The mean percentages of polymorphic loci of the four populations were 31.82% (NC), 29.55% (NB), 31.82% (ZJ) and 28.79% (M-V), respectively.Their average heterozygosities (H) were 0.1197, 0.1134, 0.1078 and 0.0966, respectively.Dendrogram was constructed based on the genetic distance index using the UPGMA method.Gst among the four populations was 0.1892, which meant that 18.92% genetic variation within the whole population itself came from the genetic differences among the four populations.The UPGMA tree of the four populations suggested that ZJ population is clustered with NB Population, with a genetic distance of 0.0319; NC population and M-V population are clustered together and their genetic distance was 0.0368.The high values of the heterozygosity and percentage of polymorphic loci in the ZJ, NB and NC populations indicated that these cultured bay scallop populations still have high genetic diversity which may be favorable for the genetic improvement of brood stock.These results may provide basic population genetic data for cultured bay scallop populations in China.更多还原