关键词: 离腹寡毛实蝇属, DNA条形码, mtDNA COI基因, 物种鉴定, 分子系统发育

Abstract: 【Aim】 Bactrocera is the most economically significant genus of tephritid flies. The present study aimed to make molecular identification and phylogeny analysis of common species of the genus Bactrocera. 【Methods】 Twenty-one species belonging to eight subgenera of the genus Bactrocera that were frequently intercepted from customs were identified using DNA barcoding technology based on mitochondrial cytochrome c coxidase subunit I (COI) gene. The partial fragments (about 650 bp) of the mtDNA COI gene were amplified using DNA barcoding universal primers. The obtained COI gene fragments were sequenced and aligned. The phylogenetic tree was established by a neighbor-joining (NJ) method. The intra-and inter-species genetic distances were calculated with MEGA version 5.0 software using the Kimura 2-parameter model. 【Results】 The identification results based on the phylogenetic tree were consistent with those based on morphological analyses for the 21 fruit fly species. In these species, 11 species of Bactrocera formed monophylies of themselves, the other 10 species shared one monophyly， and all bootstrap values of the original divergence among different haplotypes within the same species were over 99%. The average inter-species genetic distance between the 21 species was 35.8 times higher than the average intraspecies genetic distance of the 10 species (0.1540 vs. 0.0043). There was no overlap between intra- and inter-species genetic distances. 【Conclusion】 The results indicated that the DNA barcoding based on the partial sequence of mtDNA COI gene cauld provide rapid and accurate identification of Bactrocera species. The technology could be used in identifying and monitoring tephritid fruit fly species.

Key words:  Bactrocera, DNA barcoding, mtDNA COI gene, species identification, molecular phylogeny