烟粉虱传播瓜类褪绿黄化病毒（CCYV）与其对吡虫啉抗性的相互关系

Insecticide resistance and virus transmission in tobacco whitefly Bemisia tabaci are two serious problematic issues in agricultural production all over the world. There are many factors affecting insect insecticide resistance with many studies on mechanisms. One factor usually not to be concerned about is the impact of plant viruses on insecticide resistance of vector insects. Our previous preliminary experiments indicated that there is probably relationship between insecticide resistance and virus transmission in a vector insect, and the mechanism behind needs to be further investigated. In the present project, sensitive / imidacloprid-resistant strains of B. tabaci Q biotype and its semipersistently transmitted Cucurbit chlorotic yellows virus (CCYV) are used to elucidate the mechanisms about the interrelationship of insecticide resistance development and virus transmission ability in B. tabaci. Two aspects of experiments are designed in the project: (1) Impacts of imidacloprid resistance on CCYV transmission ability in B. tabaci will be researched about CCYV transmission characteristics including acquisition, retention, inoculation, binding efficiency. (2) Impacts of virus transmission on insecticide resistance in B. tabaci will be investigated on bioassays of imidacloprid resistance, detections of detoxification enzyme activities and expression levels of imidacloprid-resistance related gene CYP6CM1 in resistant and sensitive strains of B. tabaci. Implementation of this project may shed a new light on mechanism studies on insecticide resistance and virus transmission, and probably provides a theoretical basis for new strategies of insecticide resistance management and effective control of B. tabaci and plant viruses it tranmits.

烟粉虱的抗药性和传播植物病毒，是目前世界范围内农业生产上亟待解决的两大难题。昆虫抗药性的影响因素及机理研究很多，但植物病毒传播对介体昆虫抗药性的影响却鲜有被关注。我们前期的初步研究表明，介体昆虫的抗药性与其传播植物病毒能力可能有相互的影响，其机理值得深入研究。本申请项目拟以吡虫啉抗性烟粉虱及其半持久方式传播的瓜类褪绿黄化病毒（CCYV）为研究对象，系统探讨烟粉虱抗药性与其传毒能力的相互关系。项目研究包括两个方面的内容：（1）探究吡虫啉抗性和敏感性烟粉虱对其传播CCYV能力的影响，重点考察烟粉虱的获毒时间、持毒时间、接种时间、与病毒的结合效率等特性；（2）对比研究不带毒与携带CCYV的烟粉虱对吡虫啉抗性的变化规律，主要进行烟粉虱对吡虫啉抗药性水平测定、相关解毒酶活性检测及抗吡虫啉相关基因CYP6CM1表达量检测等。本项目的研究结果或将为烟粉虱抗药性机理和传毒机理研究提供新的思路。

烟粉虱的抗药性和传播植物病毒，是目前世界范围内农业生产上亟待解决的两大难题。昆虫抗药性的影响因素及机理研究很多，但植物病毒传播对介体昆虫抗药性的影响相对较少。本申请项目拟以吡虫啉抗性烟粉虱及其半持久方式传播的瓜类褪绿黄化病毒（CCYV）为研究对象，系统探讨烟粉虱抗药性与其传毒能力的相互关系。项目研究包括两个方面的内容：（1）探究吡虫啉抗性和敏感性烟粉虱对其传播CCYV能力的影响，重点考察烟粉虱的获毒时间、持毒时间、接种时间、与病毒的结合效率等特性；（2）对比研究不带毒与携带CCYV的烟粉虱对吡虫啉抗性的变化规律，主要进行烟粉虱对吡虫啉抗药性水平测定、相关解毒酶活性检测及抗吡虫啉相关基因CYP6CM1表达量检测等。. 项目取得了预期的研究结果，（一）CCYV提升了烟粉虱对杀虫剂吡虫啉的耐受性,即表明烟粉虱在携带CCYV后，激活了自身的解毒代谢能力，表现在抗吡虫啉相关基因CYP6CM1表达量极显著上调和解毒酶活性的短暂升高，从而提升了对吡虫啉的耐受性。（二）抗性烟粉虱有较强的传毒能力，据此我们推测，可能是由于抗性烟粉虱需要更多的取食来平衡抗性升高所带来体内的能量消耗，从而在增加取食行的同时，导致快速获毒和失毒（即持毒能力下降）。. 我们的研究结果表明，在敏感种群中，烟粉虱获得CCYV后能够提升对吡虫啉的耐受性，此外，抗性烟粉虱种群传播CCYV的能力更优于敏感性烟粉虱，那么病毒与介体昆虫在长期的协同进化与互作过程中可能形成了一种互惠互利的关系。