Mycelium of arbuscular mycorrhizal fungi (AMF) from different genera: form function and detection

It is often assumed that all species of arbuscular mycorrhizal fungi (AMF) have the same function because of the ubiquity of the arbuscular mycorrhizal symbiosis and the fact that all AMF occupy the same plant/soil niche. Despite apparent differences in the timing of evolutionary divergence and the morphological characteristics of AMF from the different genera, the majority of studies on these fungi use only species of Glomus. There is increasing evidence, however, that the mechanisms involved in the establishment of a mycorrhiza may differ for species and genera of AMF and influence their subsequent function. The aim of this paper is to highlight the diversity in the form and function of AMF from different genera, knowledge of which is vital in understanding their ecological roles. Potential use of biochemical and molecular approaches to detect AMF in planta and ex planta is also discussed.