中文摘要：

为探讨COⅠ基因作为条形码在胡椒鲷亚科鱼类物种鉴定的可行性,研究测定了胡椒鲷亚科8种鱼类51个个体线粒体COⅠ基因长度为651 bp的序列,利用MEGA 5.0计算胡椒鲷亚科种内与种间的遗传距离,基于最大似然法与贝叶斯法构建了系统进化树。结果显示：胡椒鲷亚科鱼类种间平均遗传距离（0.142）显著大于种内平均遗传距离（0.003）,物种间遗传距离均大于Hebert推荐的物种鉴定最小种间遗传距离0.020（2%）。系统进化树上,同一物种不同个体间均能形成独立的单系分支,表明COⅠ基因可作为胡椒鲷亚科物种鉴定的有效条形码基因。研究同时揭示,在形态分类上被认为是同种异名的两种胡椒鲷（条纹胡椒鲷与东方胡椒鲷）的COⅠ基因序列差异达到0.070,有可能是两个独立的物种。此外,在属级水平,少棘胡椒鲷属与胡椒鲷属种类之间的平均遗传距离小于胡椒鲷属内部种间的遗传距离,支持少棘胡椒鲷归属于胡椒鲷属的观点。

英文摘要：

To explore whether COⅠ sequences could be used as the DNA barcodes in the identification of Plectorhynchinae species, we analyzed the 651 bp COⅠ sequences from 51 individuals of 18 Plectorhynchinae fish in this study. The genetic distances between and within species were calculated using MEGA 5.0, and the molecular phylogenetic trees were constructed using the maximum likelihood and Bayesian inference methods. The results showed that the average inter-species genetic distance（0.142） was 47 times higher than the average intra-species genetic distance（0.003）. All the interspecies genetic distances were larger than the minimum value 0.020（2%） suggested by Hebert for the species identification. In the molecular phylogenetic trees, each individual of the same species could form an independent monophyletic group, indicating that COⅠ could be potentially used as an effective barcode gene in the rapid and accurate identification of Plectorhynchinae species. According to the genetic distance values, we found that two Plectorhinchus species, P. orientalis and P. vittatus which were conventionally regarded as synonyms, could be actually two distinct species because of their large COⅠ genetic variations（0.070）. The average genetic distance between Diagramma and Plectorhinchus was lower than the values of intra-Plectorhinchus species, which implied that the genetic variation between Diagramma and Plectorhinchus might be below the significant level. This supported the notion that Diagramma could be classified into the Plectorhinchus genus.