The antifungal effect of shell nanoparticles of chitosan aspartate obtained by in situ self-assembly of protonated macrochains was studied against 9 species of assomycetes and 2 species of basidiomycetes of various physiological and ecological groups and during artificial infection of soft wheat seedlings with the pathogenic fungus Rhizoconia sp. in vitro culture. It was found that the biopreparation has antifungal activity against a wide range of soil-dwelling saprotrophic and phytopathogenic fungi, increasing with increasing concentration of the preparation in the range of 0.001–0.1 g/dl. Suppression of mycelial growth under the influence of nanoparticles was noted for the fungi Trichoderma harzianum (up to 81.3%), Fusarium oxysporum (39.1%), Schizophyllum commune (37.9%), Lecanicillum aphanocladii (30.4%), Alternaria sp. (33.0%), Botrytis sp. (30.0%), Trichoderma viride (25.3%), Sclerotinia cf. sclerotiorum (18.0%), Rhizocionia sp. (15.0%), Talaromyces sayulltensis (7.0%) and Pleurotus ostreatus var. Florida (6.1%). At the same time, a stimulating effect of a low concentration of nanoparticles on the growth of the assomycete T. sayulltensis (20%) isolated from the rhizosphere was found. Rhizocionia sp. in vitro culture in comparison with other phytopathogens demonstrated higher resistance to the biopreparation, however, seed treatment with nanoparticle dispersion followed by cultivation on an artificial infectious background in the presence of fungal spores reduced the degree of damage and the level of development of the plant disease to 33%. Possible mechanisms of the antifungal action of chitosan nanoparticles are discussed. The obtained data allow us to propose preparations based on the dispersion of chitosan aspartate nanoparticles as a safe biodegradable antifungal drug in the practice of plant protection from phytopathogenic fungi.
O. V. Tkachenko (Wed,) studied this question.