Antifungal activity of macrofungi extracts on phytopathogenic fungal strains of genera Fusarium sp. and Alternaria sp

During the last decades, intensive application of synthetic fungicides in the agricultural crop protection practice caused growing concern for the existence of toxic chemical residues in food as well as in the whole environment. Instead of using synthetic fungicides, it is suggested that crop protection be carried out by using preparations based on compounds of natural origin (secondary metabolites of plants or microorganisms, including macrofungi from Basidiomycota) as biological control agents. The potential of macrofungal species as biocontrol agents was analyzed in this investigation of eight autochthonous species from different locations in Serbia. Both the terricolous species: Coprinus comatus, Coprinellus truncorum, Amanita strobiliformis, Hydnum repandum and the lignicolous species: Flammulina velutipes, Stereum subtomentosum, Trametes versicolor and Bjerkandera adusta were examined, with an aim to detect some novel sources of antifungal agents. This study surveyed antifungal activity of selected macrofungal extracts (MeOH, EtOH and CHCl3) against phytopathogenic Fusarium and Alternaria strains isolated from garlic, soybean and rice: F. proliferatum, F. verticillioides, F. proliferatum, F. graminearum and A. padwickii. Microdilution method in 96 well microplates was applied for the estimation of antifungal effects of macrofungi extracts in the range from 24.75 to 198.00 mg/ml and determination of minimal inhibitory (MIC) and minimal fungicidal concentration (MFC). EtOH extract of mychorhizal species H. repandum showed antifungal activity against all analyzed phytopathogenic strains, with the strongest effect on Fusarium strains (MIC 24.75 mg/ml; MFC 24.75 mg/ml). Among others, MeOH extracts of S. subtomentosum and C. micaceus showed similar effects while only B. adusta showed slight effect on Fusarium strains (MIC 24.75-99.00 mg/ml; MFC 24.75-99.00 mg/ml) and none effect on A. padwickii. The obtained results indicate the possibility of using examined extracts as efficient antifungal agents and provide the basis for the new formulations of biocontrol agents against phytopathogenic fungi in the future. nema