Dissertation Research: Drivers of plant invasions: The role of fungi, nutrient availability and competition among plants

入侵物种是全球生物多样性丧失的主要驱动力，每年花费数十亿美元进行控制。了解为什么特定物种成为入侵者对于开发有效的管理方法至关重要。在这方面，入侵植物与其相关真菌之间的相互作用可能特别重要。这些相互作用是值得注意的，因为真菌对植物既有积极的影响，也有消极的影响;一些真菌可能通过提高植物的竞争能力而使植物受益，另一些真菌可能通过引起疾病而损害植物。这项研究将确定真菌的多样性和影响的湿地草，共同芦苇（芦苇），既有本地和入侵形式在北美。将进行实验，以确定真菌是否不同地影响如何本地和入侵形式的共同芦苇应对不断变化的营养条件。除了更好地了解真菌如何帮助传播一些入侵物种外，这项研究的结果还可能揭示真菌如何以新的方式控制入侵物种的传播。此外，该项目将为研究生和本科生提供重要的研究培训。研究成果将通过科学会议、在同行评审的期刊上发表文章以及为儿童设计的入侵物种海报进行分享，该海报在路易斯安那州巴吞鲁日的一个受欢迎的自然公园展出。虽然澳大利亚对虾的本土基因型在北美广泛分布，但欧洲基因型在过去150年中迅速传播。利用田间调查和温室实验，将测试以下关于芦苇入侵性的预测：入侵芦苇基因型将1）具有较低的叶片和土壤真菌多样性，2）具有较少的叶片和土壤病原体的损害，和3）与本地基因型相比，在竞争和养分吸收能力方面具有上级。此外，还将进行测试，以确定营养物质的可用性，土壤真菌和植物竞争是否以复杂的方式相互作用，以促进来自欧洲的澳大利亚P. australis基因型的入侵成功。将在整个北美进行叶面和土壤真菌的实地调查，以确保充分复制本地和入侵的P. australis基因型，并最大限度地提高所遇到的真菌的多样性。将在实验室中从患病的叶片组织中培养叶面真菌，并将使用DNA测序来鉴定培养物和土壤样品中的真菌。还将进行植物-土壤反馈温室实验，以研究土壤生物区系、养分和竞争对原生和入侵基因型芦苇适合度的相互作用。

Invasive species are major drivers of biodiversity loss worldwide and cost billions of dollars each year to control. Understanding why particular species become invasive is critically important to developing effective methods for their management. In this regard, the interactions between invasive plants and their associated fungi may be particularly important. These interactions are noteworthy because fungi can have both positive and negative effects on plants; some may benefit plants by increasing their competitive ability and others may damage plants by causing disease. This study will determine the diversity and impacts of fungi on a wetland grass, common reed (Phragmites australis), that has both native and invasive forms in North America. Experiments will be conducted to determine whether fungi differently influence how native and invasive forms of common reed respond to changing nutrient conditions. In addition to providing a better understanding of how fungi may help spread some invasive species, results from this study may reveal how fungi can be used in novel ways to control the spread of invasive species. Furthermore, this project will provide important research training for graduate and undergraduate students. Research findings will be shared through scientific meetings, publications in peer-reviewed journals, and a poster on invasive species that is designed for children and displayed at a popular nature park in Baton Rouge, Louisiana.Although native genotypes of P. australis are widely distributed in North America, a European genotype has spread rapidly over the past 150 years. Using field surveys and a greenhouse experiment, the following predictions regarding the invasibility of P. australis will be tested: invasive P. australis genotypes will 1) have lower foliar and soil fungi diversity, 2) have less damage from foliar and soil pathogens, and 3) be superior in competitive and nutrient uptake ability in comparison to native genotypes. In addition, tests will be performed to determine if nutrient availability, soil fungi, and plant competition interact in complex ways to promote invasion success of P. australis genotypes from Europe. Field surveys of foliar and soil fungi will be conducted throughout North America, ensuring adequate replication of native and invasive P. australis genotypes and maximizing the diversity of fungi encountered. Foliar fungi will be cultured in the laboratory from diseased leaf tissue, and DNA sequencing will be used to identify fungi from cultures and soil samples. A plant-soil feedback greenhouse experiment will also be conducted to examine the interactive effects of soil biota, nutrients, and competition on the fitness of native and invasive genotypes of P. australis.