Quantification of three vesicular-arbuscular mycorrhizal fungi (Glomus spp) in roots of leek (Allium porrum) on the basis of activity of diagnostic enzymes after polyacrylamide gel electrophoresis

Abstract Leek ( Allium porrum L.) roots separately colonized by the vesicular-arbuscular mycorrhizal fungi Glomus caledonium, G. mosseae and Glomus sp. type E3 were mixed with nonmycorrhizal roots to give samples of different infection levels. Extracts of these samples were subjected to electrophoretic separation on polyacrylamide gels and stained for specific enzyme activity (esterase or glutamate oxaloacetate transaminase or peptidase). The staining intensity of the diagnostic fungal isozymes (measured as peak height on a densitometer trace) was correlated with the biomass of the fungus in the root sample and so this offers a method of quantifying the contribution of a single fungus to a mixed infection and of estimating the viability of the intraradical mycelium.