Genetic Studies of the Structure and Diversity of Arbuscular Mycorrhizal Fungal Communities

Recent studies have shown that arbuscular mycorrhizal fungi (AMF) are important components of ecosystem diversity. Traditional taxonomy suggests that global diversity is low, yet it is common to find high local diversity in field soils. Molecular methods of identification have, for the first time, allowed a characterisation of the diversity of AMF within actively growing plant roots. In this chapter, we present a summary of the AMF community structure that has been revealed in field-based studies. In particular, there are many AMF genotypes present in field systems that have not been established in culture. The genetic structure of AMF isolates has been shown to be complex. This profoundly affects the interpretation of genetic data obtained from AMF that cannot be cultured. We will review this data, and how it might make an impact on molecular analyses of field samples.