Dual axenic culture of sheared-root inocula of vesicular-arbuscular mycorrhizal fungi associated with tomato roots

Surface-sterilized sheared-root inocula of two vesicular-arbuscular mycorrhizal (VAM) fungi (Glomus intraradices and G. versiforme) from pot cultures associated with excised tomato roots showed significant sporulation and the production of an extensive hyphal biomass. As many as 10²–10³ axenic mature spores were recovered in Petri dishes during 3 months incubation in the dark. Propagules of both species were able to complete their vegetative life cycle in vitro and efficiently colonize Acacia albida roots after 1 month under greenhouse conditions. The effectiveness of 0.5 cm pieces of VAM roots as starter inocula indicates the high inoculum potential of intravesicle propagules.