基于mtDNA COI基因序列的中国柑橘果实蝇的分子鉴定及柑橘大实蝇种群的遗传多样性分析

【目的】探明危害我国柑橘的实蝇种类以及柑橘大实蝇Bactrocera minax不同地理种群和不同寄主种群的遗传多样性。【方法】利用mtDNA COI基因对危害柑橘的果实蝇进行种类鉴定,采用MEGA软件对其中28个地理种群的535头果实蝇COI基因片段(约505 bp)序列进行比对,分析种间及种内遗传距离,构建系统发育树。使用DnaSP软件分析柑橘大实蝇不同地理种群和不同寄主种群的遗传多样性。【结果】从柑橘虫果内共鉴定出4种实蝇,分别为柑橘大实蝇B.minax、桔小实蝇B.dorsalis、蜜柑大实蝇B.tsuneonis和瑞丽果实蝇B.ruiliensis。这4种实蝇的种间遗传距离为0.0264～0.2410,种内遗传距离为0.0000～0.0140,种间与种内遗传距离没有重叠区域。单个柑橘虫果内一般仅有1种实蝇,极个别柑橘果实可同时被两种实蝇危害(4/43);在这些为害柑橘的实蝇种类中,以柑橘大实蝇的个体数量比例最大,占90.70%。柑橘大实蝇地理种群遗传多样性高,28个种群共有17个单倍型。【结论】柑橘大实蝇是所调查地区柑橘实蝇的绝对优势种,其种群遗传分化程度较高,扩散危害风险大。本研究结果对柑橘果实蝇类的监测和防控具有重要意义。

Molecular identification of citrus fruit flies and genetic diversity analysis ofBactroceraminax(Diptera: Tephritidae) populations in China based on mtDNA COI gene sequences

【Aim】To clarify the species of fruit flies that harm citrus and the geneticdiversity of different geographical populations and different host populations of theChinese citrus fruit fly, Bactrocera minax in China. 【Methods】 The mtDNA COI gene wasdetected to identify the species of fruit flies that harm citrus. The sequences of thismtDNA COI gene fragment (about 505 bp) of citrus fruit flies of 535 individuals from the 28geographical populations were aligned, and the inter- and intra-species genetic distancewas calculated and the phylogenetic tree was constructed by using MEGA software. Thegenetic diversity of different geographical populations and different host populations ofB. minax was analyzed by using DnaSP software. 【Results】 Four species of fruit flies (B.minax, B. dorsalis, B. tsuneonis, and B. ruiliensis) were identified from the infestedcitrus fruits, with the inter-species genetic distance of 0.0264-0.2410 and theintra-species genetic distance of 0.0000-0.0140. There was no overlap between the intra-and inter-species genetic distances. There was usually only one fruit fly species insingle citrus fruit, and very few fruits were harmed by two species of fruit flies (4/43).Among all the fruit fly species, the proportion of B. minax individuals was the highest(90.70%). The genetic diversity of geographical populations of B. minax was high, and therewere 17 haplotypes in 28 populations. 【Conclusion】 In the regions surveyed in this study,B. minax is the dominant fruit fly species that damages citrus fruits. There exist a highdegree of genetic differentiation and a high risk of proliferation hazard of B. minax. Theresults of this study are helpful for monitoring and controlling citrus fruit flies.