摘要： 采用微卫星标记技术,对吉富品系尼罗罗非鱼(GIFTstrain)抗病群体和易感病群体进行了遗传差异分析。结果显示:在30个微卫星位点中20个能扩增出多态性高、重复性好的清晰条带;抗病群体和易感病群体的平均等位基因数分别为2.5,2.4个;观测杂合度和期望杂合度分别为0.469和0.441,0.440和0.476;多态信息含量PIC分别为0.359和0.379;UNH845和UNH189位点在抗病群体中偏离Hardy-Weinberg平衡(P<0.05),GM180位点在易感病群体偏离Hardy-Weinberg平衡,2个群体间的遗传距离和遗传分化指数为0.055和0.054。此外,GM251和GM462位点的差异等位基因片段(135,198bp)在抗病群体中出现的频率显著高于易感病群体,推测这2个基因片段与抗病性状存在一定的连锁关系。以上结果表明,吉富品系尼罗罗非鱼抗病群体与易感病群体之间的遗传多样性差异不明显,筛选出2个与抗病性状相关的微卫星标记,为开展吉富品系尼罗罗非鱼抗病品种分子标记辅助选育奠定了基础。

关键词: 吉富品系尼罗罗非鱼, 微卫星, 遗传多样性, 遗传标记

Abstract: Technology with microsatellite was used to analyze the genetic difference between disease-resistant and disease-susceptible groups of GIFT strain. The results show that there were 20 loci successfully amplified with stable target bands within 30 tested loci to identify the polymorphism for the tested GIFT strain. The average alleles in disease-resistant was 2. 5 slightly higher than that of 2. 4 in disease-rusceptible group. Then the average of observed heterozygosity(Ho) and expected heterozygosity(He) were 0. 469 and 0. 441, 0. 440 and 0. 476 respectively and the polymorphism information content (PIC) was 0. 359 and 0. 379. Genetic similarity index and genetic distance was 0. 055 and 0. 054 respectively. The locus UNH845,UNH189 and GM180 showed significant departure from Hardy Weinberg equilibrium after sequential bonferroni correction(P<0. 05)in two groups. GM251 and GM462 sites differences of allele fragment(135,198 bp) were positively related to disease-resistance GIFT strain. Above mentioned results indicated that the genetic diversity between disease-resistant and disease}usceptible group of GIFT strain was not significantly different, and the GM251 and GM462 gene fragment with its differential bands from the PCR ampliftcation can be used as the molecular marker for the disease}esistant GIFT strain molecular assistant selection.

Key words: GIFT strain, Microsatellite, Genetic diversity, Genetic marker

中图分类号: 

• Q78