The classification proposed by Morton & Benny (1990) was based on the cladistic analysis of 57 species of AMF carried out by Morton (1990), which used phenotypic characters of spores and mycorrhiza, together with considerations of spore ontogeny and germination mode. The results showed that the AMF form a monophyletic group defined by the establishment of a mutualistic symbiosis with plant roots and arbuscle formation.
In this classification, the AMF were kept in the Phylum Zygomycota, but removed from the order Endogonales and transferred to the new order Glomerales (published as Glomales), with two suborders, three families and six genera. Later, Morton and Redecker (2001) recognized two new families and two new genera.
Phylum: Zygomycota
Class: Zygomycetes
Order: Glomerales
Suborder: Glomineae
Family: Glomeraceae
Genera: Glomus, Sclerocystis
Family: Acaulosporaceae
Genera: Acaulospora, Entrophospora
Suborder: Gigasporineae
Family: Gigasporaceae
Genera: Gigaspora, Scutellospora
Morton JB, Benny GL (1990) Revised classification of arbuscular mycorrhizal fungi (Zygomycetes). A new order, Glomales, two new suborders, Glomineae and Gigasporineae, and two new families, Acaulosporaceae and Gigasporaceae, with an emendation of Glomaceae. Mycotaxon 37:471–491