【作者】 Buahom Nopparat（陈英才）；

【导师】 李志红；

【作者基本信息】 中国农业大学 ， 植物检疫与农业生态健康， 2014， 博士

【摘要】 番石榴果实蝇Bactrocera (Bactrocera) correcta (Bezzi)是为害番石榴、柑橘类、芒果和辣椒等多种热带、亚热带瓜果的重要害虫,分布在亚洲地区。随着国际贸易及人员往来的发展,番石榴果实蝇容易随寄主水果作远距离传播,对进口国的农业生产构成极大的威胁。本研究采用线粒体COI基因序列分析技术及微卫星DNA标记技术相结合的方法,研究主要分布区内番石榴果实蝇的种群遗传结构,揭示番石榴果实蝇的扩散路线、趋势及中国云南地区番石榴果实蝇的入侵来源,为植物检疫及生物入侵防控部门提供决策支持。主要结论如下：1)本研究以线粒体COl基因序列为分子标记,对来自中国(云南)、泰国、老挝、缅甸、越南、斯里兰卡及印度7个国家20个地理种群的793头番石榴果实蝇样品进行了种群遗传结构研究。结果显示：主要分布区内番石榴果实蝇种群存在显著的遗传结构,种群间不存在距离隔离现象,且单倍型多样性随着采样位点经度的增加而减小,表明主要分布区内番石榴果实蝇很有可能具有由西向东的扩散趋势。该虫在主要分布区内可能有两条扩散路线：一是在季风的作用下从南亚地区向东扩散到云南西部地区并在该地区定殖、积累形成一定种群数量后,逐渐传入缅甸曼德勒地区,形成南亚→中国云南西部→缅甸曼德勒的扩散路线；二是从泰国及老挝中部地区,通过自然传播或人为传播途径,传入泰国北部、老挝北部及云南南部,然后再通过云南南部的景洪向北扩散到云南内陆及云南中部地区,再由该地区扩散到云南东部及越南地区,形成泰国及老挝中部→泰国北部、老挝北部及云南南部→云南中部→云南东部及越南的扩散路线。2)本研究选用了磁珠富集法来首次开发番石榴果实蝇微卫星引物,创建了其微卫星(AC)15文库,结果发现磁珠富集率高达52.31%。利用TP-M13-SSR技术对74头自然种群样品进行多态性检测后发现,所涉及的12个位点中共有117个等位基因；各位点的总等位基因数范围在6-14间,多态信息含量在0.41-0.79间。在所涉及的12个位点中有10个位点处于哈迪温伯格平衡,无偏离连锁不平衡现象,表明所开发的12个SSR位点具有较高的多态性,能够作为可靠的分子遗传标记。3)本研究利用以上自主开发的12个SSR位点,研究了来自以上5个国家(除印度和斯里兰卡)18个地理种群的781头番石榴果实蝇样品的种群遗传结构。结果显示：番石榴果实蝇种群中存在显著的遗传结构,不存在距离隔离现象,且所分析的18个种群间迁移率普遍较高；云南西部德宏州的芒市及南部西双版纳州的景洪地区很有可能是番石榴果实蝇在中国最早的入侵地区,云南东部及越南地区番石榴果实蝇种群发生时间最晚,云南中部很有可能是该地区番石榴果实蝇的主要来源。更多还原

【Abstract】 The guava fruit fly, Bactrocera (Bactrocera) correcta (Bezzi)(Diptera:Tephritidae) is one of the most important pests of many kinds of tropical and subtropical fruits and vegetables, such as guavas, citruses mangoes and chili peppers. It is mainly distributed in Asia. With the growth of international trade and human activities, this fly can easily follow the transport of its host plants and perform a long-distance dispersal, posed a threat to agricultural production of importing countries. With the aim of investigating population genetic structure, invasion routes and expansion trend of B. correcta in the main distribution areas, and to reveal the sources of invasion of this fly in Yunnan province of China, We have analysed the combinative data of mitochondrial COI sequences and microsatellite markers, and got the following conclusions:1) We used mtDNA COI sequences as genetic markers to analyse population genetic structure of793B. correcta individuals colleted from20sites in7countries, including China (Yunnan), Thailand, Laos, Myanmar, Vietnam, Sri lanka and India. Our study suggests that the overall genetic structure of this fly in main distribution areas was significant. There has no sign of Isolation-by-distance. Haplotype diversity decreased with the increasing of longitude of collection sites, it showed that this fly has expanded from west to east with a limited geographical scale. Two main invasion routes of B. correcta are inferred:(1) As the results of monsoon in Bengal, this fly performed eastward dispersal from South Asia to Western Yunnan of China, then established its population in that area and gradually spread to Mandalay of Myanmar, that formed the spread route as South Asia→Western Yunnan→Mandalay (Myanmar);(2) As the results of natural dispersal or human activities, this fly performed northward dispersal from Central Thailand and Laos regions to Southern Yunnan, Northern Thailand and Laos regions, and then introduced into Yunnan province through Jinghong region in Southern Yunnan. Finally, this fly gradually northward expansed to Central Yunnan and eastward expansed to Eastern Yunnan and Vietnam, respectively. That formed the spread route as Central Thailand and Laos→Northern Thailand, Northern Laos and Southern Yunnan→Central Yunnan→Eastern Yunnan and Vietnam.2) We firstly used a biotin-streptavidin capture method to isolate12microsatellite markers of B. correcta from a (AC)15microsatellite library. The enrichment efficiency was52.31%. The polymorphism of these microsatellite loci was tested in74individuals collected from two natural populations using TP-M13-SSR technique. Based on our research,117allele were found in all12loci, the number of allele per locus varied from6-14, the polymorphic information contents ranged from0.41-0.79.10loci were conformed to HWE. No significant departures from linkage disequilibrium were found between each pairs of loci. These12microsatellite markers demonstrated high levels of polymorphism. It can be used as reliable markers for the studies of population genetic structure in this fly. 3) We used all above microsatellite loci to analyse population genetic structure of781B. corrceta individuals collected from above18sites in5countries (except for Sri Lanka and India). Our study suggests that the overall genetic structure of this fly in18sites was significant. There has no sign of Isolation-by-distance. The migration rates between all18populations were generally high. Based on our study, B. correcta might be invaded into Yunnan province through Mangshi in Western Yunnan and Jinghong in Southern Yunnan. B. correcta populations in Eastern Yunnan and Vietnam region occurred lately, the populations in Central Yunnan might be the sources of invasion in this region.更多还原