Mycobiome and Pathogenic Fusarium Fungi in the Rhizosphere of Durum Wheat After Seed Dressing with Debaryomyces hansenii

Debaryomyces hansenii naturally colonize wheat grain and can potentially inhibit the pathogens responsible for Fusarium crown rot (FCR). Seed dressing is a recommended method for protecting crops against FCR pathogens. The effectiveness of seed dressing with antagonistic yeasts in reducing the incidence of FCR remains insufficiently investigated. The aim of this study was to evaluate the effect of seed dressing with a triazole fungicide and a suspension of D. hansenii cells on the health status and development of durum wheat cultivars (Durasol and Floradur), and to analyze the structure of the mycobiome in the rhizosphere of seedlings. Under field conditions, the incidence of FCR was reduced by 57.1% by triticonazole and 35.7% by the biocontrol agent relative to the control treatment. Seed dressing with D. hansenii decreased the number of operational taxonomic units (OTUs) of Fusarium pathogens by 47.24% in cv. Durasol and 87.4% in cv. Floradur. The number of OTUs of autochthonous yeast species and Mortierellomycota increased in the rhizosphere of both durum wheat cultivars. The effectiveness of seed dressing with yeasts is determined by the quality and local adaptation of biocontrol agents.