点带石斑鱼遗传多样性的RAPD分析

采用RAPD标记技术对海南点带石斑鱼养殖群体和野生群体的遗传结构进行了初步研究.从100个随机引物筛选出20个,在养殖群体和野生群体各20尾中分别扩增出183和176条DNA片段,其中多态性片段的比例分别为67.57%和75%,平均杂合度分别为0.498 0和0.531 1,遗传相似率分别为0.816 5和0.794 6,群体间遗传距离为0.329 6.Shannon遗传多样性指数表明,两群体中的遗传变异有40.95%来自群体内,而59.05%来自群体间.野生群体的多态位点比例和杂合度明显高于养殖群体.点带石斑鱼与野生群体相比,养殖群体的杂合度和遗传多样性有所下降,提示在点带石斑鱼的人工繁育过程中应引进标记辅助选择等技术手段.

Population Genetic Diversity of Epinephelus Malabaricus with RAPD Markers

The genetic structure of the raised population and wild population of Epinephelus malabaricus were studied by RAPD technique.Genomic DNA was extracted from 20 individuals of each population.Amplification with 20 rendom primers of one hundred generated 185 and 176 fragments of raised and wild populations respectively.The proportion of polymorphic fragments were 67.57% and 75%,respectively.The value of average heterozygosity for the two populations were 0.498 0 and 0.531 1,respectively.The genetic similarities for the two populations were 0.816 5 and 0.794 6,respectively.The genetic distance of the two populations was 0.329 6.Shannon index of phenotype diversity between the two populations were 0.590 5.The proportion of polymorphic fragments and heterozygosity of the wild population was higher than raised population.It indicated that the wild resource of E.malabaricus was in good condition.The lower heterozygosity and genetic diversity in the raised population suggested that the approaches such as marker assisted selection should be introduced into grouper breeding programs.