Arbuscular Mycorrhiza in the Living Collections at the Royal Botanic Garden Edinburgh

Most plants have mutualistic symbioses (mycorrhizas) with certain fungi that occupy their roots, the most common of which fall into the category known as arbuscular mycorrhizas (AM). Although most of the arbuscular mycorrhizal fungi (AMF) are entirely subterranean, some form spore masses or sporocarps sufficiently large to be seen with the unaided eye on the surface of the substrate. During several decades of casual observation in the research greenhouses at the Royal Botanic Garden Edinburgh (RBGE), such clumps of spores from several species of AMF have been recorded. A brief introduction to mycorrhizas, with an emphasis on AM, is provided. A list of host plants grown in botanic gardens or similar situations from which AMF have been identified is given. The possible value of AMF is discussed in relation to the ‘ecosystems’ that develop in mature botanic garden greenhouses. Ways of using AMF to improve the establishment or growth of plants are discussed, including a suggestion that adequate controls must always be used, particularly when using previously untested commercially available products.