Inhibitory activity of alcoholic extracts of ediblefungi against Rhizoctonia solani.

Fungal diseases represent one of the causes of annual crop losses. Rhizoctonia solani is a pathogenic fungus with worldwide distribution associated with root and tuber diseases of different crops; it causes important economic losses in perennial and annual plants, including almost all horticultural crops. To mitigate losses due to fungus, fungicides of synthetic origin have been used; however, many of these substances are associated with carcinogenicity and are toxic to the environment. Edible macromycete mushrooms are a source of antifungal compounds to control diseases in agricultural crops. This work evaluated the antifungal activity of extracts of edible mushrooms (Lactarius deliciosus, Ustilago maydis, Amanita jacksonii and Amanita rubescens) against the phytopathogen R. solani by means of three techniques: diffusion of wells, discs and plate dilution. The results show that with the diffusion of wells, no effect was observed on the growth of R. solani with the alcoholic extracts and their dilutions. While with disc diffusion, a qualitatively slower growth was observed compared to the controls of R. solani with the ethanolic extract of A. jacksonii and in its 1:1 dilution of methanol-water. In the plate dilution, it was found that the 1:1 ethanol water dilution of L. deliciosus had 88% inhibition on the growth of R. solani, followed by the ethanol extract of L. deliciosus (65%), methanol extract from U. maydis (63%) and methanol extract from L. deliciosus (57%). Therefore, the extracts and the dilution must be studied in greater depth, by being tested in an in vivo system and identifying the secondary metabolites present. [ABSTRACT FROM AUTHOR]