基于多变量形态度量学和线粒体Cyt b序列的鲈属鱼类分类探讨

Systematics of Perca Species Based on Multivariate Morphometrics and Mitochondrial Cytochrome b Gene Variation Analysis

鲈属鱼类的分类在学术界尚存在很多争议。本文通过鲈属鱼类32个多变量形态学参数和1134bp的线粒体DNA细胞色素b序列的比较,对鲈属鱼类分类问题做了探讨。结果显示河鲈和伊犁鲈之间的形态距离为0.15,黄金鲈和伊犁鲈为0.14,河鲈和黄金鲈为0.09,在形态上黄金鲈和河鲈较接近,而伊犁鲈与前两者差异明显;主成分2(16.09%)对主成分1(21.71%)作图结果显示黄金鲈和河鲈有重叠区,而伊犁鲈与其它二种鲈有较大差距;细胞色素b同源序列差异百分比为河鲈与伊犁鲈13.08%、黄金鲈与伊犁鲈10.68%、黄金鲈与河鲈11.47%,鲈属鱼类间的碱基差异属于种间的遗传差异。MP、NJ和ML三种系统发育树在河鲈、黄金鲈和伊犁鲈三个种或亚种之间的拓扑结构一致,显示黄金鲈与伊犁鲈的演化关系较河鲈为近。根据20个样本的细胞色素b基因序列的遗传差异和系统发育树以及地理分布上的繁殖隔离,我们进一步认定黄金鲈和河鲈是不同的种,鲈属鱼类包括伊犁鲈、河鲈和黄金鲈三个种。

This paper investigated the classification of the genus Perca based on the 32 multivariate morphometrics and the 1134bp sequences of mitochondrial cytochrome b （Cyt b） gene. The result of multivariate morphometric analyses showed that the distance between P. fluviatilis and P. schrenki, between P. schrenki and P. flavescens, between P. fluviatilis and P. flavescens was 0.15, 0.14, 0.09, respectively. Percafluviatilis and P. flavescens were much more similar in morphology, and there was a remarkable difference between P. schrenki and the two other species. In the scatter-plot figure based on principal components 1 to 2, there was an overlapping section between P. fluviatilis and P. flavescens, but there was no overlapping section between P. schrenki and the two others. In the analysis of mitochondrial cytchrome b gene, the percentage nucleotide sequence divergence between P. fluviatilis and P. schrenki, between P. schrenki and P. flavescens, between P. fluviatilis and P. flavescens was 13.08%, 10.68%, 11.47% respectively. The sequence divergences among the three Perca species were within interspecific divergence. Molecular phylogenetic trees were constructed based on the sequences of 20 samples with maximum parsimony （MP）, neighbor-joining （NJ） and Maximum likelihood methods. The topological structures of the three trees were consistent, and they all showed that the relationship between the P. schrenki and P. flavescens was much closer than that between P. fluviatilis and P. flavescens. From the genetic divergence of the Cyt b gene and the isolation in geographic distribution, we further concluded that P. fluviatilis and P. flavescens were different species. The genus Perca therefore, includes three species, P. fluviatilis, P.schrenki and P. flavescens.