金银花蚜虫寄主转换化学生态机制研究

Semiaphis heraclei is the most serious pest of Lonicera japonica. The use of chemical pesticides has caused pesticide residue which has seriously affected the safety of edible and clinical use of honeysuckle. The life cycle of S. heraclei involves seasonal switch between unrelated summer and winter host plants. The host alternation mechanism is still unclear. Based on previous study, we speculated that the volatiles of the host plant play an important role in the host location of the aphid during the host alternation. In this study, chemical communication between S. heraclei and its winter host L. japonica, summer host Daucus carota will be investigated. Multidisciplinary techniques will be adopted to analyze host volatiles of L. japonica and D. carota to find out key components that attract migrants of S. heraclei. Key olfactory genes of S. heraclei will be screened and functional identified. Chemical communication mechanism of S. heraclei and its host plants during host alternation will be demonstrated from the view of insect behavior, electrophysiology and molecular biology. It is helpful to not only reveal the coevolution mechanism between the aphid and its host plants, but also provide a theoretical basis for integrated pest management of S. heraclei.

胡萝卜微管蚜是金银花的主要害虫，利用化学农药对其防治造成金银花农残问题严重影响其临床用药和食用安全。该蚜虫随季节变化在冬季和夏季寄主植物间转换，其机制尚不明确。基于前期研究，我们推测寄主转换时寄主植物的挥发物在该蚜虫寄主定位中起重要作用。阐明胡萝卜微管蚜与寄主植物的化学通讯机制，对该蚜虫的科学防治至关重要。本研究拟以胡萝卜微管蚜及其冬、夏寄主金银花和胡萝卜为研究对象，围绕寄主转换时胡萝卜微管蚜对寄主植物挥发物的应答反应，从行为学、电生理学和分子生物学入手，深入剖析该蚜虫识别寄主植物的物质基础和分子机理，揭示胡萝卜微管蚜和寄主植物之间的化学通讯机制，为金银花蚜虫的科学防治提供理论依据。

金银花是重要的药食同源植物，胡萝卜微管蚜是其主要害虫，生产上普遍使用化学农药对其防治造成严重的农残问题。本研究系统调查该蚜虫生活史及发生规律，同时研究了寄主转换期有翅型对次生寄主的识别机制，主要结果如下：（1）纠正了文献报道的性母和雄蚜回迁的片面认识，证实了有翅孤雌蚜也可以回迁；秋季有性世代发生时间集中且种群数量低（约10头/枝条），是全年防控的关键期；春季谷雨前后是种群数量爆发的关键期，是春季防控窗口期；（2）寄主转换时由无翅型转变的有翅型向次生寄主迁飞，室内行为学研究发现有翅型具有明显回避原生寄主趋向次生寄主，对两种寄主植物挥发物进行分析为引诱剂和趋避剂的研发提供基础；（3）两型触角扫描电镜观察发现次生感觉圈在两型中差异最大；触角转录组结果显示4个OBPs：SherOBP2、SherOBP6、SherOBP7和SherOBP10，2个CSPs：SherCSP1和SherCSP2和3个ORs：SherOR43、SherOR64和SherOR51在有翅型特异高表达，推测参与次生寄主挥发物嗅觉识别；（4）雌雄性蚜交尾年高峰在11月中旬，日高峰在12：00-13：00，雌雄性比10：1；雌雄性蚜形态存在明显的性二型，触角差别最大，次生感觉圈在雄蚜触角分布，雌性蚜缺少，推测其在配偶识别过程中性信息素的感受中起重要作用。本研究探明了金银花上胡萝卜微管蚜种群爆发机制，揭示了寄主转换期有翅型对次生寄主的识别机制，同时推测性信息素在雌雄识别中起重要作用，为胡萝卜微管蚜的科学防控提供依据，在学术和生产实践中均有一定价值。