团头鲂3个地理种群杂交效果的配合力和微卫星标记预测

利用12对微卫星(SSR)引物对采自梁子湖、鄱阳湖和淤泥湖3个地理种群团头鲂的遗传多样性、杂合度和遗传距离进行了分析,并以3个种群的团头鲂为亲本,用完全双列杂交方法建立全同胞家系,对F1个体体质量、全长进行了配合力分析,以期预测各种群间配组的杂交优势。在一般配合力分析中,父本全长和体质量配合力效应值大小依次为淤泥湖、鄱阳湖和梁子湖;母本全长的配合力效应值大小依次为鄱阳湖、淤泥湖和梁子湖,体质量的配合力效应值依次为梁子湖、鄱阳湖和淤泥湖。在特殊配合力分析中,鄱阳湖团头鲂种群内杂交组合相对效应值最大,其次为梁子湖作为母本与淤泥湖作为父本的组合,最小的为鄱阳湖作为母本与淤泥湖作为父本的组合。对3个种群进行群体遗传学分析发现:3个地理种群的团头鲂均具有较高程度的遗传异质性,鄱阳湖群体的平均多态性信息含量最大(0.848),淤泥湖最小(0.820);有效等位基因数以及标记索引值的结果和多态信息含量一致;3个群体的近交系数均为负值。梁子湖与淤泥湖群体间的遗传距离最大(0.3362),梁子湖和鄱阳湖群体间的遗传距离最小(0.2356)。通过配合力和微卫星分子标记分析,可初步预测子代生长性状最佳的组合为梁子湖团头鲂作为父本淤泥湖团头鲂作为母本。

Prediction of hybrid vigor among three geographical populations of Megalobrama amblycephala by combination ability and SSR markers

Hybrid vigor among three geographical populations of Megalobrama amblycephala, including Liangzi Lake population (L), Poyang Lake population (P) and Yuni Lake population (Y), was predicted by combination ability and SSR markers. The first generation individuals of 9 complete diallel cross combina-tions of three populations were measured with total length and body weight. The analysis of combination ability showed that the sire of Yuni population had the largest general combining ability effective value; however, the largest general combining of total length in dam was Poyang population, while that of body weight was Liangzi population. There were high effective combinations among P♂×P♀, L♂×Y♀ and Y♂×Y♀ which had high specific combining ability, so these combinations were suitable as basic selective popula-tions. The results obtained from SSR markers showed that all three populations had high genetic heteroge-neity (He, 0.877-0.863), polymorphism information content (PIC, 0.848-0.820) and marker index (MI, 8.959-11.242). Among the three populations, Liangzi population and Yuni population revealed the largest genetic distance, reaching 0.336 2. According to the result, L♂×Y♀ would have the highest hybrid vigor among those combinations.