新疆香梨优斑螟种群遗传结构及扩散趋势研究

Xinjiang has developed into one of the major fruit producing areas in China, due to its specially geographical location and climatic conditions. As one of the important pillar industries of Xinjiang Agriculture, Kuerle fragrant pear (Pyrus sinkiangensis), Akesu red fuji apple (Malus domesticac) and Xinjiang jujube (Zizyphus jujuba), has long been sold at home and abroad. However, Factors, such as the rapid expansion of cultivation area and the trend of monoculture, are leading to new disasters of insects (Euzophera pyriella) concerned widely. The larvae damage tree phloem, cause the function in damaged parts lost, make tree vigor weak, increase the risk of rot disease,even cause tree dead and orchard destroyed. The larvae bring harm to the fruit, causing fruit rot and drop, and losing its commercial value. E. pyriella is the multinational quarantine object in pears and apples export, increasing export costs and trade risk. Therefore, it is imminent to build a scientific system of prevention and control, but the unclear disastrous mechanism is the main constraint. By studing the genetic structure of the pest population, it may resolve this issue quickly. In this study, through the method of COI, ND5 and SSR molecular markers to study 26 geographical populations in Xinjiang and four different host populations of the pest, it will clearify the genetic structure of each population of E. pyriella. And combining with historical data, geographic information, cultivating structure and agricultural management information, it will analysize the molecular mechanisms of caused disaster and the trend of diffusion (gene flow) of E. pyriella.

新疆因特殊的地理位置和气候条件，已发展成我国主要水果产区之一，其中库尔勒香梨、阿克苏苹果及新疆红枣，早已销往海内外，成为新疆农业重要的支柱产业之一。然而，栽培面积快速扩大和品种单一化趋势明显等因素，导致新灾害性昆虫- - 香梨优斑螟备受关注。其幼虫为害树体韧皮部，造成受害部位失去功能，引起树势衰落，腐烂病发病率上升，重者死树毁园；幼虫蛀食果实，造成烂果、落果，失去商品价值；香梨优斑螟也是梨和苹果出口多国的检疫对象，增加了果品出口成本和贸易风险。因此，构建科学系统的防控体系迫在眉睫，但其成灾机制不清楚是主要制约因素，通过该害虫的种群遗传结构研究，可快速解决此问题。项目利用COI、ND5和SSR分子标记技术,研究来自全疆26个地理种群和4个不同寄主的种群，以明确香梨优斑螟各种群遗传结构特征，结合其历史资料、地理信息、种植结构和农业措施等信息，分析香梨优斑螟成灾的分子机制及扩散趋势（基因流）。

新疆因特殊的地理位置和气候条件，已发展成我国主要水果产区之一，其中库尔勒香梨、阿克苏苹果及新疆红枣，早已销往海内外，成为新疆农业重要的支柱产业之一。然而，栽培面积快速扩大和品种单一化趋势明显等因素，导致新灾害性昆虫--香梨优斑螟备受关注。其幼虫为害树体韧皮部，造成受害部位失去功能，引起树势衰落，腐烂病发病率上升，重者死树毁园；幼虫蛀食果实，造成烂果、落果，失去商品价值。因此，通过该害虫的种群遗传结构研究，有助于揭示害虫成灾及扩散机制。在新疆、甘肃和陕西境内进行了香梨优斑螟的调研工作，并在甘肃的张掖等地发现了香梨优斑螟，其他地区也发现类似害虫，这也是首次记录香梨优斑螟在新疆以外的区域存在。在新疆和甘肃的14个区域采集香梨优斑螟种样品633个用于群遗传结构研究，其中获得线粒体COI基因片段序列585条、ND5基因片段序列583条，用于种群遗传结构分析，也完成香梨优斑螟线粒体全基因组测序工作。利用磁珠富集和转录组两种方法获得大量香梨优斑螟的SSR序列信息，从中240对引物中筛选出15对具有在不同种群中稳定扩增引物，选择了8对多态性丰富的引物用于SSR种群遗传结构分析，初步阐述了种群之间遗传信息交流情况，对研究香梨优斑螟在新疆的扩散模式奠定基础。