生物防治对入侵植物防御策略和竞争能力适应性进化的影响

外来植物逃逸原产地专食性昆虫的取食，以及在新的选择压力下发生的适应性进化是推动其成功入侵的重要因素。目前，采取生物防治的方法，向入侵地引入专食性昆虫已成为治理入侵植物的重要手段。然而，引入的生防昆虫也可作为选择压力，驱动入侵植物发生适应性进化，使其在防御与竞争之间以及不同防御策略之间重新分配资源，进而影响生物防治的效果。但是到目前为止，我们对这种资源再分配的方向及其所产生的生态后果还知之甚少。本项目在已有工作基础上，以恶性入侵植物豚草及其生防昆虫广聚萤叶甲为研究体系，选取已被防治和未被防治的豚草种群，通过同质园实验、生物测定、生理生化分析和野外调查，研究：（1）生物防治对豚草抵抗力、忍耐力和竞争力适应性进化的影响；（2）以上进化反应对生物防治效果的影响。研究结果将有助于从新的角度完善植物-昆虫的共进化理论，并为生物防治长期效果的预测提供重要的理论依据。

The success of invasive plants has often been attributed to release from native specialist insect herbivores and subsequent evolutionary changes. Currently, the intentional introduction of specialist herbivores to invasive areas (biological control) has become the major method to control invasive plants. However, the altered selection after such introduction can lead to adaptive evolution in resource allocation between defense and competitive ability, and between different defensive strategies of invasive plants, thereby influencing efficiency of biological control. But so far, little is known about the direction of this resource reallocation and its ecological consequences. Here, based on previous work, we will address these research gaps using an invasive plant Ambrosia artemisiifolia and its specialist leaf beetle Ophraella communa as a study system. We will conduct common garden experiments, herbivore bioassays, physiological and biochemical analyses and field surveys to compare A. artemisiifolia populations with and without biological control history. We will study: 1) how the introduction of Ophraella communa affected evolutionary changes of resistance, tolerance and competitive ability of the invasive A. artemisiifolia; 2) how these evolutionary responses in A. artemisiifolia influenced the efficiency of biological control. This study will provide new insight into co-evolved theory between plants and herbivores, and have important implications for the assessment of the long-term efficiency of biological control.