Effectiveness of promising antagonist strains against the Phoma rot pathogen of winter rapeseed under artificial infection conditions in a humidity chamber in vitro

In the central zone of the Krasnodar region and the southern NonChernozem regions of Russia, Phoma rot (caused by the pathogen Leptosphaeria maculans (Desm.) Ces. et De Not., conidial stage Phoma lingam (Tode) Desm.) is one of the most harmful diseases affecting winter rapeseed. The biomethod laboratory of V.S. Pustovoit AllRussian Research Institute of Oil Crops developed the concept of targeted production of effective microbiological preparations. One of the concept's stages involves a gradual screening of collection antagonist strains against the pathogen on the background of artificial infection. The first stage of a secondary screening of promising antagonist strains selected in the primary screening was carried out on the background of artificial infection of winter rapeseed seeds with the Phoma lingam in a humidity chamber in vitro. On the background of severe artificial infection with the Phoma rot pathogen (80.0%), we selected five fungal strains (T4 Trichoderma sp., Pbc1 Penicillium brevicompactum, I3 Basidiomycota, Pp1 Penicillium purpurescens, Хk3 Chaetomium globosum) with maximum biological effectiveness of 75.0–87.5%, seven bacterial strains of the genus Bacillus (Far 8, 112, D 13, K12, 111 Bacillus sp., B5 B. licheniformis, and 5B1 B. subtilis), with maximum effectiveness of 68.8–75.0%, and two strains from the genus Pseudomonas (143 P. chlororaphis and 132 Pseudomonas sp.) with an effectiveness of 62.5%. The selected strains will undergo further testing in the next stage of secondary screening, which involves artificial infection with the pathogen in soil in laboratory conditions.