地上、地下天敌的种类及互作类型变化是植物防御特性进化的重要驱动力。入侵植物是研究植物适应性进化的理想材料, 目前的研究很少涉及地上-地下互作对入侵植物的影响。入侵植物在新生境中主要受到广食性天敌的胁迫，因此，研究广食性地上-地下天敌互作下入侵植物的响应，将能更好地阐明植物的适应性进化规律。原产我国、入侵北美的乌桕，是研究植物适应性进化的代表种之一。本项目拟在前期研究的基础上，以地下广食性根结线虫与地上专食性癞皮夜蛾、广食性斜纹夜蛾开展同质园实验和温室实验，比较具明确亲缘关系的原产与入侵地乌桕种群对地上-地下天敌互作的影响、及植物在不同类型地上-地下互作下的资源调配响应；并联用气相色谱-质谱、液相色谱-质谱检测技术，全面分析乌桕不同部位主要次生代谢产物的变化。研究结果将有助于揭示地下广食性天敌与地上不同食性天敌互作下植物的适应性进化响应机制，丰富入侵生物学及进化生态学理论。

Changes in categories as well as interactions between above- and belowground herbivores are important driving forces for adaptive evolution of plant defense traits. Invasive plants are ideal materials for studying adaptive evolution of plant, and few researches have shown how above- and belowground herbivores interact to affect invasive plant performance. As invasive plants are main attacked by generalist herbivores in new ranges, studies on the responses of invasive plants to above- and belowground generalist interactions will provide broader insights into the adaptive evolutionary mechanisms of plant. Native to China and invasive to North America, Chinese tallow is one of the representative models for studying adaptive evolution of plants. Based on our previous studies, we proposal to conduct common garden and greenhouse experiments to compare interactions between root-knot nematode and aboveground insects with different diet width (the specialist Gadirtha inexacta and the generalist Prodenia litura), mediated by genetically related genotypes of invasive and native tallow populations, and investigate the differences in resource allocation strategies of relative plants. We further employ the combination of gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) technologies to comprehensively analyze the secondary metabolites of above- and belowground plant parts under different interaction stresses. The results will elucidate adaptive evolutionary responses of plant to changes in the interactions between two spatially separated herbivores, and provide new insights into invasive biology as well as evolution ecology.