The effect of three basidiomycetous fungal species on soil-borne, foliage and fruit-damaging phytopathogens in laboratory experiments

The effect of three basidiomycetous fungi, Meira geulakonigii, M. argovae and Acaromyces ingoldii on strains of seven phytopathogenic fungal species was assayed in the laboratory. The phytopathogens were placed on dialysis membranes covering media in which the basidiomycetous fungi were formerly cultured. A. ingoldii inhibited the growth of all phytopathogens tested, whereas Meira spp. suppressed their growth to a lesser extent. Upon being returned to extract-free media, all phytopathogens resumed their growth, suggesting a fungistatic effect of the basidiomycetous fungi. These fungi inhibited the growth of Sclerotina sclerotiorum on tomato leaves for a few days and Meira spp. hindered the infection of oranges by Penicillium digitatum, whereas A. ingoldii was less effective. Results of preliminary biochemical assays suggest that neither competition for hydrocarbons nor secreted proteases are responsible for the inhibitory activity of the basidiomycetous fungi, which was probably due to the secretion of unidentified substances by these fungi.