利用微卫星分子标记技术对鳜鱼人工选育群体遗传结构进行分析,并以鳜鱼长江野生群体作为对照群体。结果显示,筛选的5个微卫星位点在3个鳜鱼群体中的平均多态信息含量均超过0.50,其中鳜鱼广东清远群体和广东佛山群体的多态信息含量(分别为0.6686和0.6186)比鳜鱼长江野生群体低(为0.7788);3个鳜鱼群体的平均期望杂合度由大到小依次为:鳜鱼长江野生群体〉鳜鱼广东清远群体〉鳜鱼广东佛山群体;鳜鱼广东清远群体与鳜鱼长江野生群体的Nei氏遗传距离为0.3476,鳜鱼广东佛山群体与长江野生鳜鱼群体的Nei氏遗传距离为0.4238,且鳜鱼广东清远群体与鳜鱼长江野生群体的遗传相似性较高。试验结果表明,人工选育鳜鱼群体的遗传多样性比野生鳜鱼群体遗传多样性要低;其中鳜鱼广东清远群体与鳜鱼长江野生群体亲缘关系更近,说明经过多年选育仍然保留较高的遗传多样性。
Five microsatellite markers were used to analyze the genetic structure in three populations of mandarin fish Siniperca chuatsi, including two artificial selection populations (Foshan population and Qingyuan population) and one wild population (Yangtze River population). Five loci were found to be polymorphic (PIC〉0.50) in the three populations. The Foshan population and Qingyuan population had PIC values of 0. 6686 and 0. 6186, lower than the Yangtze River population. There were expected heterozygosity (He) value of 0. 7243 in Qingyuan population, 0. 82803 in Foshan populations and 0. 6698 in Yangtze River population. Genetic distance between Qingyuan population and Yangtze River population (value 0. 3476) was found shorter than that in genetic distance between Foshan population and Yangtze River population (value 0. 4238). The findings indicated that the selective breeding led to reduction in the genetic diversity of mandarin fish, Qingyuan population having the more advantages of variety breeding and artificial breeding than Foshan population.