Collaboration: The Role of Plant-Pathogen Interactions in Explaining and Constraining Weed Invasions: Testing Theories of Biotic Resistance and the Natural Enemies Hypothesis

加州大学伯克利分校吉尔伯特和帕克分校-圣克鲁兹分校-9806517&9808501入侵生物生态学的一个核心问题是，为什么一些引进的植物物种无法在栖息地成功，而另一些物种则成为种群众多的有毒入侵者。提出了两种相互竞争的理论来回答这个问题，重点是天敌在调节入侵植物物种种群动态中的作用。天敌假说是经典生物防治计划的基础，该假说提出，成功的入侵者会在自己的栖息地留下控制它们的害虫和病原体。生物抵抗力假说认为，大多数入侵生物是天然食草动物和病原体的成功目标，成功的入侵是正常情况下的例外。本项目将使用三叶草和三叶草作为模型系统来验证这两个假设。它将使用田间和温室实验相结合的方法来研究植物与病原体的相互作用，以比较本地和外来三叶草，试图区分不同地点的情况。它将检验疾病抗药性在本地宿主中更普遍的预测--这与生物抗药性假说是一致的。

Gilbert & Parker University of California-Berkeley & -Santa Cruz DEB - 9806517 & 9808501 A central question in the ecology of invading organisms involves why some introduced plant species fail to succeed in a habitat while others become noxious invaders with high populations. Two competing theories have been posed to answer this question focusing on the role of natural enemies in regulating the population dynamics of invading plant species. The natural enemies hypothesis, the foundation for classical biological control programs, proposes that successful invaders leave behind the pests and pathogens that control them in their home habitats. The biotic resistance hypothesis suggests that most invading organisms are the successful targets of natural herbivores and pathogens and that successful invasions are the exception to the usual run of things. This project will test these two hypotheses using clover and burclover as a model system. It will examine plant-pathogen interactions using a combination of field and greenhouse experiments to compare native vs. exotic clovers in trying to sort through situations in different locations. It will test the prediction that disease resistance should be more prevalent in native hosts - consistent with the biotic resistance hypothesis.