云南边境地区果实蝇属种类DNA条形码鉴定

Identification of Bactrocera species from the border areas of Yunnan province,southwestern China using DNA barcoding (Diptera: Tephritidae)

【目的】果实蝇属Bactrocera中有国际上重要的检疫性害虫,基于形态的物种鉴定有一定的局限性。另一方面,云南边境地区为东南亚地区实蝇入侵我国的重要通道。因此,对该地区实蝇分子鉴定方法的研究对于该属物种的快速准确鉴定具有重要意义。本研究旨在探讨DNA条形码技术在果实蝇属物种鉴定中的有效性。【方法】使用线粒体基因COI和COII序列的通用引物对果实蝇属20个物种60份样品进行PCR扩增、测序和序列分析;采取距离方法和建树方法评价2种序列的鉴别能力。【结果】COI和COII序列平均长度分别为682 bp和339 bp,种内和种间遗传差异较大,有较明显的遗传距离间隔(barcoding gap),鉴定成功率分别为91.2%和90.7%。另外,分子系统树表明华实蝇亚属Sinodacus不是单系群。【结论】COI和COII序列均能够将绝大多数果实蝇属物种进行准确鉴别,应用COI或COII序列进行果实蝇属物种鉴定具有一定的可行性。

[ Aim ] A lot of Bactrocera species are important international quarantine pests. However, intra-specific morphological variation can become a serious limitation for the correct identification at the species level. The border areas of the Yunnan province, southwestern China are an important channel of invasion for Southeast Asian fruit fly. Developing a new method for identification of the fruit fly species has important significance for the rapid and accurate identification of the species. The aim of this study was to explore the effectiveness of species identification of DNA barcoding technology in the genus Bactrocera. [ Methods ] In this study, sixty samples from twenty species of Bactrocera were tested. Two mtDNA sequences, i. e., COI and COH sequences, were amplified and sequenced. The species identification efficiency for the two barcodes was assessed by distance-based method and neighbor-joining method. [ Results ] The average length of COI and COH sequences was 682 bp and 339 bp, respectively. There existed high intra-specific and inter-specific genetic variability and significant barcoding gap. The rates of successful identification with COI and COH sequences were 91.2% and 90.7% , respectively. The phylogenetie analyses suggest that the subgenus Sinodacus is not a monophyletie group. [ Conclusion ]COI and COIl genes can be used to correctly identify the most species of Bactrocera.