昆虫取食对油菜和野芥菜之间基因流的影响机理

Herbivory directly affects the plant growth, and plants possess numerous defense strategies to counteract the effects. However, little is known about defence strategies associated with reproduction and inter-specific gene flow. To increase scientific knowledge in this field, we propose natural and control experiments in fields of the selected model species, oilseed rape (Brassica napus) and its wild relative, the wild mustard (B. juncea). We will explore the development characteristics of reproductive organs, sex allocation, trade-offs of resource allocation to vegetative and reproductive organs, and the hybridization rate between oilseed rape and wild mustard. In particular, we propose to study heritance processes behind response signals to progenies, and assess whether these signals can contribute to increase of insect-resistance. We will use PCR, SSR and other molecular detecting technologies to accomplish this goal. We expect that our results will (1) reveal response mechanisms of plants to improve reproductive defence strategies related to herbivory, (2) show whether herbivory affects inter-specific gene flow, and (3) elucidate patterns of inheritance and of long-term effects of plant response to herbivory. Hence, our study will provide a comprehensive contribution to studies on plant-insect interaction, and to evolutionary biology of plant reproductive organs.

昆虫取食直接影响植株的生长发育，植株对此做出响应，选择相应的防御策略。然而，昆虫取食对植物繁殖策略和种间基因流的影响却鲜有研究。本项目以油菜(Brassica napus)及其野生种野芥菜(B. juncea)为研究对象，采用自然条件观测和人工控制试验方法，同时结合PCR、SSR等分子检测技术，研究油菜和野芥菜繁殖器官的形态特征、性别分配比例、植株的资源投入权衡，以及油菜和野芥菜的杂交率等方面。此外，我们还将研究植株对昆虫取食的响应信号能否传递到后代，提高后代的抗虫性。研究结果将(1)揭示植株的繁殖系统对昆虫取食破坏的响应机制，(2)明确昆虫取食破坏植株是否影响作物和野生种间基因流的发生频率，(3)阐明植株对昆虫取食响应的遗传效应和长期影响。本项目将有助于探究植株-昆虫间的相互关系，推动植物繁殖器官的进化生物学研究。

昆虫取食直接影响植株的生长发育，植株对此做出响应，选择相应的防御策略。然而，昆虫取食对植物繁殖策略和种间基因流的影响却鲜有研究。本项目以油菜(Brassica napus)及其野生种野芥菜(B. juncea)为研究对象，采用农田观测和农田控制试验方法，同时结合PCR、SSR等分子检测技术，研究油菜和野芥菜繁殖器官的形态特征和性别分配比例，以及油菜和野芥菜间的基因流等方面。研究结果显示(1)油菜和野芥菜的繁殖器官花朵形状、花粉数量和大小、胚珠数量和大小等对低度昆虫取食没有明显的响应；(2)野芥菜和油菜的共存与竞争，不仅对野芥菜生长繁殖有负面影响，还降低了野芥菜的花粉-胚珠比，改变了植株的繁殖分配策略；(3)油菜和野芥菜共存时的基因流概率平均为0.67%，且昆虫取食降低了作物和野生种间基因流的发生频率。本项目将有助于探究植株-昆虫间的相互关系，推动作物与近缘野生种之间基因流的研究。