Introduction and persistence of arbuscular mycorrhizal fungal inoculum

点击翻译按钮获取中文摘要

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.