Variation in certain isozymes amongst different geographical isolates of the vesicular-arbuscular mycorrhizal fungi Glomus clarum, Glomus monosporum and Glomus mosseae

Abstract Variation between different isolates of three species of vesicular-arbuscular mycorrhizal fungi ( Glomus clarum, Glomus monosporum and Glomus mosseae ) was investigated by using the eiectrophoretic mobilities of six enzymes extracted from resting spores. Some intra-specific variation was observed but after numerical analysis of the data, isolates of G. monosporum and G. mosseae formed a cluster which was clearly distinguishable from the G. clarum isolates and from Glomus caledonium . A single isolate of Glomus manihotis fitted within the G. clarum cluster. Isozyme analysis allowed unidentified or tentatively identified isolates to be compared with fungi which had been classified on the basis of spore mophology.