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文章采用微卫星标记技术,对吉富品系尼罗罗非鱼(GIFT strain Oreochromis niloticus)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、重复性好和扩增条带清晰;抗病群体和易感病群体的平均等位基因数分别为2.5和2.4个;观测杂合度和期望杂合度分别为0.476和0.453,0.44和0.457;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,两个群体间的遗传距离和遗传分化指数0.055和0.054。此外GM251和GM462位点的差异等位基因片段(135bp和198bp)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。
In this paper, microsatellite markers were used to analyze the genetic differences between the resistant and susceptible populations of GIFT strain Oreochromis niloticus. The results showed that 20 of 30 microsatellite loci amplified high polymorphism, good repeatability and clear bands; the average number of alleles in disease-resistant and susceptible groups was 2.5 and 2.4; the observed heterozygosity and expected heterozygosity were 0.476 and 0.453, 0.44 and 0.457 respectively; the polymorphism information content (PIC) was 0.359 and 0.379 respectively; UNH845 and UNH189 sites deviated from Hardy-Weinberg equilibrium ). The GM180 locus deviated from Hardy-Weinberg equilibrium in susceptible population. The genetic distance and genetic differentiation index between two populations were 0.055 and 0.054, respectively. In addition, the allelic fragments of GM251 and GM462 (135bp and 198bp) had some linkage with disease resistance traits. The above results showed that there was no significant difference in genetic diversity between the resistant and susceptible populations of the two genotypes, two microsatellite markers were screened for disease resistance. Non-fish resistant varieties of molecular marker assisted selection laid the foundation.