广西沿海及其邻近海区拟穴青蟹群体遗传多样性的RAPD分析

采用随机扩增多态DNA（random amplified polymorphic DNA,RAPD）技术检测广西沿海及其邻近海区拟穴青蟹（Scylla paramamosain）6个地理群体的遗传变异和遗传结构,8条10 bp寡核苷酸随机引物扩增99个个体,分析其中的44个位点,31个位点表现出多态性,在种水平的多态位点百分率为70.45%。POPGENE分析结果显示,6个群体的多态位点百分率为29.55%～54.55%,平均为36.97%;群体的遗传多样性自高至低排列为钦州湾群体〉党江群体〉珍珠湾群体〉闸口群体〉清化群体〉流沙湾群体;群体内的遗传变异大于群体间的遗传变异,群体间的遗传分化程度较大。AMOVA分析显示,群体内遗传变异占87.03%,群体间遗传变异占12.97%,群体间发生中等程度遗传分化。Mantel检测结果表明,拟穴青蟹6个群体间的遗传距离与地理距离之间的相关性不显著。聚类分析表明,群体间聚类无明显的地域性分布格局。

RAPD analysis of genetic diversity of Scylla paramamosain population in Guangxi and neighboring sea areas

Random amplified polymorphic DNA （RAPD） technology was employed to investigate the genetic diversity and structure of 6 Scylla paramamosain populations in Guangxi and its neighboring sea areas. We amplified a total of 99 individuals by using 8 random primers with 10 bp in length, and analyzed 44 valid loci, among which 31 loci are disclosed as polymorphism. The percentage of poly- morphic locus （PPL） at species level is 70.45%. According to POPGENE analysis, the PPL in the 6 populations ranges from 29.55% to 54. 55% with an average of 36. 97%. The abundance of genetic diversity is QZW 〉 DJ 〉 ZZW 〉 ZK 〉 QH 〉 LSW. Vari- ance within populations is higher than that among populations, and genetic differentiation among populations reaches higher level. An analysis of molecular variance （AMOVA） shows that variance within populations accounts for 87.03% , and that among populations accounts for 12. 97%. However, genetic differentiation among populations only reaches medium level. Mantel test shows that no signif- icant correlation between genetic and geographic distance is detected in the 6 S. paramamosain populations. Cluster analysis indicates that the distribution of these populations displays no apparent geographic pattern.