Introduction and persistence of arbuscular mycorrhizal fungal inoculum

当外来物种被引入时，生态系统会发生什么？如果这些外来物种恰好是土壤微生物呢？虽然入侵物种对植物和动物的负面影响是众所周知的，但当入侵微生物被引入新环境时，它们是如何改变和被改变的，我们知之甚少。丛枝菌根（AM）真菌是根栖微生物，构成了可能是世界上最重要的互惠共生的一半。AM真菌是大多数植物必不可少的根共生体，为其宿主提供一系列益处，如改善营养吸收、水关系和保护免受病原体侵害。AM真菌被商业化生产用于应用场合，包括农业、林业和景观恢复。虽然在过去的十年里，数以吨计的外来微生物已经被应用到土壤生态系统中，但我们对这种引入的影响知之甚少。微生物会建立并持续存在吗？它们会影响宿主植物吗？它们是否改变了本地微生物群落？如果没有这些信息，应用土壤微生物可能是浪费金钱（因为微生物可能无效），并且可能是有害的。我的研究将揭示AM真菌最能在新系统中建立和持续存在的条件。结合温室、体外和实地研究，我将利用AM真菌的生活史策略信息来预测哪些真菌最有可能在该领域建立并持续存在。有了这些信息，我将建立一系列温室和田间试验，在这些试验中，我将测试不同的AM真菌在具有不同本土AM真菌群落的土壤中持续存在的能力。最后，我将评估这些引入如何影响本地真菌群落，使用定量和定性分子方法的组合。最终，从这项拟议的研究中产生的信息将告知从业人员和政策制定者关于AM真菌接种物的使用。它也将有助于形成一个基础的最佳实践工具，为从业者希望使用AM真菌接种。

What happens to ecosystems when exotic species are introduced? What if these exotic species happen to be soil microbes? While the negative effects of invasive species are well known for plants and animals, very little is known about how invasive microbes can change and be changed when they are introduced into new environments. Arbuscular mycorrhizal (AM) fungi are root-dwelling microbes that constitute one half of what may be the world's most important mutualism. AM fungi are essential root symbionts for most plants, providing their hosts with a suite of benefits such as improved nutrient uptake, water relations and protection from pathogens. AM fungi are produced commercially for use in applied situations, including agriculture, forestry and landscape restoration. While literally tonnes of foreign microbes have been applied to soil ecosystems over the past decade, we know little about the effects of such introductions. Do the microbes establish and persist? Do they influence their plant hosts? Do they change the indigenous microbial communities? Without such information, application of soil microbes may be a waste of money (as the microbes may be ineffectual), and could be detrimental. My research will reveal the conditions where AM fungi are best able to establish and persist in novel systems. Using a combination of greenhouse, in vitro and field studies, I will use information about the life history strategies of AM fungi to predict which fungi are most likely to establish and persist in the field. With this information, I will establish a series of greenhouse and field tests where I will test different AM fungi for their ability to persist over time in soils with different indigenous AM fungal communities. Finally, I will evaluate how these introductions affect the indigenous fungal communities, using a combination of quantitative and qualitative molecular approaches. Ultimately, the information produced from this proposed research will inform both practitioners and policy makers about the use of AM fungal inoculum. It will also help form the basis of a Best Practices tool for practioners wishing to use AM fungal inoculum.