广西东方蜜蜂遗传多样性分析

Genetic diversity of Apis cerana in Guangxi,China

【目的】东方蜜蜂Apis cerana是我国重要的经济昆虫,是生态循环中的重要环节,对其进行种群遗传研究能为东方蜜蜂遗传资源的发现、保护和利用提供基础。广西是我国东方蜜蜂重要的产区和分布区之一。【方法】本研究通过33个形态标记、38个微卫星标记和tRNAleu-COⅡ片段的线粒体标记,对广西东方蜜蜂进行遗传分化、特征和遗传多样性分析。【结果】根据形态逐步判别-聚类分析、主成分-聚类分析,微卫星DAPC、Structure分析、聚类树分析、Fst、AMOVA分析,以及线粒体的Fst分析,结果显示广西东方蜜蜂没有发生种群遗传分化。广西东方蜜蜂的微卫星遗传多样性水平在各样点间较为稳定,但线粒体遗传多样性在广西不同样点间的差异较大。线粒体遗传结构易受人为影响,受人为影响小的9个样点线粒体结构中以Acmt01001为主要单倍型;在活框饲养技术发达的北流样点和北海样点,线粒体遗传结构的主要单倍型有2-3种,且Acmt01001比例不是最高的,这意味着人工育王等人为干扰影响较大。【结论】在广西环境基本一致且种群数量较大,基因流通畅的条件下,最远距离约650 km的样点间没有发生遗传分化,意味着东方蜜蜂仅由距离导致遗传分化的距离要大于650 km。根据广西东方蜜蜂遗传多样性现状,对广西东方蜜蜂遗传资源保护和利用提出了建议。

[Objectives]Apis cerana is an economically essential insect that plays a significant role in pollination and that is well adapted to different ecological environments in China.Population genetic research can provide a basis for the discovery,protection and utilization of the genetic resources of this species.Guangxi province is the main A.cerana producing region in China.[Methods]Genetic differentiation,genetic characteristics and genetic diversity of A.cerana were analyzed in Guangxi using 33 morphological markers,38 microsatellite markers and a mitochondrial marker of a tRNAleu-COⅡfragment.[Results]None of a suite of analytical methods,including morphological stepwise discriminant-cluster analysis,principal component-cluster analysis,microsatellite DAPC,structure analysis,cluster analysis,Fst value,mitochondrial Fst value or AMOVA,found evidence of genetic differentiation in A.cerana in Guangxi.However,although microsatellite genetic diversity of bees from different sample sites in Guangxi was relatively similar,differences were apparent in mitochondrial markers which are susceptible to influence by human factors.Acmt01001 was the main mitochondrial haplotype at 9 sample sites with little human influence.However,the mitochondrial genetic structure at the Beiliu and Beihai sites obviously differed from that at other sites in that 2 or 3 haplotypes other than Acmt01001 were the main haplotypes,a situation probably caused by unscientific breeding and other artificial interference.[Conclusion]The population size of A.cerana in Guangxi is large and gene flow is frequent.There is no evidence of genetic differentiation over a range of 650 km.In order to protect and utilize the locally adapted genetic resources of A.cerana we suggest that a nature reserve be established.