中文摘要：

为了研究南海大斑石鲈（Pomadasys maculatus）不同地理群体的遗传多样性情况,作者测定了东兴、乌石、潭门、闸坡4个群体共计61尾大斑石鲈控制区的993 bp序列。检测出变异位点35个,单倍型47种,平均单倍型多样性指数为0.9884,核苷酸多样性指数为0.0076,总体表现出高单倍型多样性和低核苷酸多样性的特点,其中潭门群体核苷酸多样性相对较高（0.00879）。中性检验结果显示 Fu’s Fs值均为显著负值–5.34（P=0.03）,核苷酸不配对分布没有显著偏离群体扩张模型呈现出单峰（SSD值和Rg指数较小）,表明大斑石鲈在历史上经历过种群扩张,推测扩张时间约4.74万-1.18万年间。群体间（0.0065-0.0089）与群体内遗传距离（0.0066-0.0089）处于同一水平,总遗传分化指数Fst为–0.0057（P〉0.05）,群体间基因流Nm=33.76。不同组群划分方式的分子方差分析均表明群体内遗传差异显著大于群体间,遗传变异主要来源于群体内部。南海海域大斑石鲈群体遗传多样性匮乏,群体间不存在显著的遗传分化,可划归一个管理保护单元,潭门群体建议优先给予保护。

英文摘要：

This study determined 993bp mtDNA control region sequences of 61 individuals collected in Dongxing, Wushi, Tanmen, and Zhapo where 35 variable sites defined 47 haplotypes. Global haplotype （Hd） and nucleotide diversity （Pi） were 0.9884 and 0.0076, respectively thus indicating a pattern of high haplotype diversity and low nucleotide diversity. A combination of the significant negative neutral test values of Fu’s Fs （-5.34,P= 0.03）, the mismatch distribution pattern, and the network analysis revealed that a historical population expansion occurred at about 47400–11800 years ago. The genetic distance between populations （0.0065–0.0089） was at a similar level to the genetic distance within populations （0.0066–0.0089）; the overall genetic differentiation index （Fst） was -0.0057 （P〉 0.05）, the gene flow coefficient （Nm） among four populations was 33.76, and the analysis of molecular vari-ance showed that most of the genetic variations of the four populations was distributed throughout the populations. In addition, genetic diversity was low and genetic divergence was inconspicuous between populations ofPomadasys maculatus. It is thus suggested thatP. maculatus in the coastal waters of the South Sea should be maintained as a single management unit and that the Tanmen population within contains arelatively high genetic diversity and should thus be a priority for protection.