基于mtDNA COI基因的离腹寡毛实蝇属常见种DNA条形码识别和系统发育分析

DNA barcoding and phylogenetic analysis of common species of the genus Bactrocera( Diptera: Tephritidae) based on mtDNA COI gene sequences

【目的】离腹寡毛实蝇属Bactrocera昆虫是最具经济重要性的实蝇类害虫，本研究依据mtDNA COI基因碱基序列对离腹寡毛实蝇属常见实蝇种类进行识别鉴定与系统发育分析。【方法】以口岸经常截获的离腹寡毛实蝇属8个亚属21种实蝇为对象，采用DNA条形码技术，通过对mtDNA COI基因片段 （约650 bp）的测序和比对，以MEGA软件的K2-P双参数模型计算种内及种间遗传距离，以邻接法（NJ） 构建系统发育树。【结果】聚类分析与形态学鉴定结果一致，除11种单一序列实蝇外，其他10种实蝇均各自形成一个单系，节点支持率为99%以上。种内（10种）遗传距离为0.0003～0.0068，平均为0.0043；种间（21种）遗传距离为0.0154～0.2395，平均为0.1540；种间遗传距离为种内遗传距离的35.8倍，而且种内、种间遗传距离没有重叠区域。【结论】基于mtDNA COI基因的DNA条形码技术可以用于离腹寡毛实蝇属昆虫的快速鉴定识别，该技术体系的建立对实蝇类害虫的检测监测具有重要意义。

【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.