基于线粒体16S rRNA基因序列对3种珍珠贝的鉴定

传统的形态鉴定主要依赖于分类者的经验和水平,容易产生分类错误。为提高物种鉴定的准确性,作者采用形态学与线粒体16S rRNA基因序列分析相结合的方式对广西北海涠洲岛采获的3种珍珠贝进行了鉴定。研究结果表明,基于形态学可将3种珍珠贝分别鉴定为企鹅珍珠贝(Pteria penguin)、宽珍珠贝(P.loveni)和中国珍珠贝(P.chinensis),但基于16S r RNA基因序列,形态学鉴定为P.loveni的标本应为P.lata。P.loveni和P.lata是两个完全独立的种,并非为同物异名。珍珠贝属16S rRNA基因序列的种间遗传距离明显大于种内遗传距离,适宜作为该属种类鉴定的分子标记。在基于16S r RNA基因序列构建的系统树中,相同种类的不同个体均形成单系群,并获得很高的支持率。分布于中国沿海的珍珠贝属种类应包括P.lata,是否有P.loveni的分布尚需进一步证实。

Species identification of three Pteria species based on mitochondrial 16S rRNA gene

Species identification based on morphology highly relies on the ability of taxonomists. Some species can be easily misidentified based on morphological characteristics alone. To improve the accuracy of species identification, three Pteria species sampled from Weizhou Island, Guangxi, were identified based on shell morphology and mitochondrial 16S rRNA gene sequences. These three species were identified as P. penguin, P. loveni and P. chinensis, respectively, based on shell morphology. However, the specimen that was identified as P. loveni based on morphological characteristics was later identified as P. lata using 16S rRNA gene sequences. P. loveni and P. lata are two distinct species and are not synonyms. The genetic distances are much higher between species than within species, indicating that 16S rRNA gene is useful for species identification in the genus Pteria. P. lata is a valid species, and P. loveni exists in China, with no further confirmation required.