Antagonistic Potential of Macrolepiota sp. Against Alternaria Solani as Causal Agent of Early Blight Disease in Tomato Plants

The aim of this study was to identify a Mexican native basidiomycete strain with antagonistic potential against phytopathogenic fungi. The antifungal activity of fifteen isolates against Fusarium oxysporum, Fusarium solani, Colletotrichum truncatum, Colletotrichum coccodes, Colletotrichum sp., Stemphylium solani, Botrytis cinerea, Epicoccum nigrum, Phomopsis sp. and Alternaria solani was studied in vitro using dual culture assay. An isolate of Macrolepiota sp (CS185) exhibited the strongest ability to compete on potato dextrose agar medium (PDA) causing 22.2 up to 46.6% inhibition in seven out of ten pathogens evaluated. The addition of 30% Macrolepiota sp. liquid filtrates (from 7 day-cultures in potato dextrose broth) to PDA plates inhibited 66% of A. solani growth. Application of Macrolepiota sp. CS185 culture fluids to control early blight disease caused in tomato plants by A. solani under greenhouse conditions diminished disease incidence and percent of damage. The length of the stems, the roots and the foliar area increased in the treated plants and, above all, the foliar symptoms decreased by 73%. Sesquiterpene lactones and quinones identified in culture fluids might be responsible for Macrolepiota antifungal activity. This study proves that Macrolepiota sp. CS185 culture filtrates have potential in biocontrol of early blight disease.