牙鲆4个选择性繁育后代群体遗传结构的微卫星分析

Genetic structure analysis among four selective offspring stocks of Japanese flounder Paralichthys olivaceus by microsatellite markers

中文关键词: 牙鲆  养殖群体  遗传多样性  微卫星分析

英文关键词: Paralichthys olivaceus  Cultured stocks  Genetic diversityMicrosatellite analysis

中文摘要:

      为了检测由3个牙鲆基础群体组合交配建立的4个选择性繁育后代群体的遗传多样性水平，本研究利用10对微卫星引物分析了其遗传结构信息。计算结果表明，等位基因数3~10个，平均等位基因数57个，有效等位基因数1357 1~4597 9，平均有效等位基因数2983 2，各个位点的平均观测杂合度0208 3~1000 0，平均期望杂合度0208 1~0795 6，多态信息含量0167 1~0750 1，其中中度多态位点两个，高度多态位点7个，各群体的多态信息含量从大到小依次为日本亲鱼与抗病亲鱼杂交后代群体、抗病亲鱼自繁后代群体、抗病亲鱼与黄海野生亲鱼繁殖后代群体、日本亲鱼自繁后代群体。分析结果表明，4个群体的遗传多态水平均较高，对4个选择性繁育后代群体的平均观测杂合度值进行X2检验表明，群体间遗传多样性差异不显著。日本亲鱼自繁后代群体与中国海域亲鱼繁育后代群体（抗病亲鱼自繁后代群体和抗病亲鱼与黄海野生亲鱼繁殖后代群体）的遗传距离较远，分别为0272 4和0331 0。根据群体间的遗传距离利用NJ法构建系统树，抗病亲鱼自繁后代群体和抗病亲鱼与黄海野生亲鱼繁殖后代群体聚为一支，日本亲鱼自繁后代群体和日本亲鱼与抗病亲鱼杂交后代群体聚为一支，对遗传偏离指数的分析表明群体间的遗传平衡差异很大。

英文摘要:

      Genetic diversity among four selective offspring stocks obtained by mating among three basic populations of Japanese flounder Paralichthys olivaceus was assessed using ten microsatellite loci. Results showed that the allele number (A) was 3-10, average allele number was 5.7, effective allele number (Ae) was 1.357 1-4.597 9, average effective allele number was 2.983 2, average observed heterozygosity (Ho) of each locus was 0.208 3-1.000 0, average expected heterozygosity (He) of each locus was 0.208 1-0.795 6, average polymorphism information content (PIC)of each locus was 0.167 1-0.7501, and polymorphism information content of JRS, RRS, RYS and JJS followed a decreasing order. Moderate and high genetic diversity was found in JJS and the other three stocks, and X2 test revealed that there was no significant difference in average observed heterozygosity of the four selective offspring stocks. Genetic distance between JJS and RRS or RYS was comparatively higher than that between RRS and RYS. The genetic distance among the four stocks was used to construct NJ dendrogram via MEGA software. RRS and RYS were within one branch, and JJS and JRS within another branch. Genetic deviation index indicated a difference among stocks. These results indicated that these microsatellite loci selected were very sensitive and could be used in further selective and genetic breeding studies of Japanese flounder.