Pathogen-Mediated Interactions Between Native and Introduced Grass Species

本研究将评估专家和通才病原体之间的相互作用，本地和引进草种。 天敌释放假说认为，引入的植物种群相对于本地人的人口成功的结果，从更大的抑制本地人的天敌。 目前的数据表明，引进的植物更完全地从专家比通才的敌人。 因此，引入的人口可能会取得更大的人口成功比本地人间接抑制他们通过病原体介导的明显的竞争，敌人的敌人假说。 拟议中的工作将使用一个实验听话的系统，本地和引进的旧场草来测试这些假设。 大规模的调查将被用来量化的变化环境病原体物种丰富度和感染率的本地和引进的草在北卡罗来纳州皮埃蒙特。 将建立每个物种的实验单一栽培，以量化病原体物种丰富度和感染率在一个共同的花园。 土壤肥力、真菌病原体感染和病毒病原体感染将在析因设计中进行操作。 调查和实验的数据将是迄今为止对病原体在生物入侵中的作用进行的最全面测试之一的前两个步骤。据估计，生物入侵每年给美国经济造成数十亿美元的损失，是对本土生物多样性的主要威胁。 这项工作可能会提出控制或减轻有害入侵物种的机制。 此外，在这些本地和引入的人群中研究的几种病原体也是农业害虫。 该项目可能会提出新的方法来生态控制其在作物系统中的爆发。 最后，这项研究旨在阐明疾病生态学的基本原则，这些原则可能适用于动物和人类群体。

This study will evaluate the role of specialist and generalist pathogens in interactions between native and introduced grass species. The enemy release hypothesis argues that the demographic success of introduced plant populations relative to natives results from greater suppression of the natives by natural enemies. Current data suggest that introduced plants are more completely released from specialist than generalist enemies. Thus, introduced populations may achieve greater demographic success than natives by indirectly suppressing them through pathogen-mediated apparent competition, the enemy of my enemy hypothesis. The proposed work will use an experimentally tractable system of native and introduced old-field grasses to test these hypotheses. Large-scale surveys will be used to quantify variation in ambient pathogen species richness and infection rates on native and introduced grasses in the North Carolina Piedmont. Experimental monocultures of each species will be established to quantify pathogen species richness and infection rates in a common garden. Soil fertility, infection by fungal pathogens, and infection by viral pathogens will be manipulated in a factorial design. Together, the data from the survey and experiment will be the first two steps in one of the most comprehensive tests to date of the role of pathogens in biological invasions. Biological invasions are estimated to cost the US economy billions of dollars per year and be a leading threat to native biodiversity. This work may suggest mechanisms for the control or mitigation of harmful invasive species. Additionally, several of the pathogens to be studied in these native and introduced populations are also agricultural pests. This project may suggest novel approaches to the ecological control of their outbreaks in crop systems. Finally, this research seeks to shed light on fundamental principles of disease ecology that may be applied to animal and human populations.