The occurrence of antagonistic bacteria in Glomus mosseae pot cultures

Abstract

Biological control of root diseases, carried out by the manipulation of resident microbes or by the introduction of antagonists, should take into account the role played by mycorrhizal fungi in the mycorrhizosphere. In this work we have detected many antagonistic bacteria within the different zones of the mycorrhizosphere of the arbuscular mycorrhizal (AM) fungus Glomus mosseae, grown for 17 years in pot cultures. The selected bacteria were actively antagonistic against in vitro mycelial growth of species of the soil-borne pathogens Fusarium and Phytophthora and on the germination and germ tube growth of Phytophthora parasitica zoospores. These results are evidence of the mycorrhizal compatibility of the antagonistic bacteria isolated from the mycorrhizosphere and suggest the possibility of using AM fungi as vehicles of selected microorganisms in biological control of soil-borne pathogens.