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To develop environmentally safe multifunctional biological preparations, we carried out the primary screening of bacterial strains (from the collection of the biomethod laboratory of V.S. Pustovoit All-Russian Research Institute of Oil Crops) against the sunflower dry rot pathogen Rhizopus oryzae Went & Prins. Geerl. by the method of double or reciprocal cultures. 17 strains of the Bacillus genus exhibited antagonistic activity against the sunflower dry rot pathogen with two types of mechanism of action (competition for feeding area and antibiosis). Strains 01 kor f and D 1-1 Bacillus sp. competed for surface feeding area and inhibited the growth of aerial mycelium of the pathogen. We observed the maximum sterile zone in three strains: 3-3 Bacillus sp. and K 1-1 B. subtilis – 4.0 mm, and P-9 B. polymyxa – 3.0 mm. 6 bacterial strains of the genus Pseudomonas had antagonistic activity against the dry rot pathogen with one type of mechanism of action – antibiosis. Strain 12-2 Pseudomonas sp. had the largest sterile zone on potato sucrose agar (PSA) (5.5 mm), and strains 14-4 and 15-1 Pseudomonas sp. had the largest sterile zone on the King B medium (5.0 and 6.0 mm). [ABSTRACT FROM AUTHOR]

The article presents the results of primary screening of a collection of fungal antagonist strains to the most widespread and harmful in the Krasnodar region isolate of dry rot pathogen Rhizopus oryzae Went & Prins. Geerl. We conducted the screening by the method of double or reciprocal cultures to develop environmentally safe microbiological preparations of multifunctional type of action. The evaluation of 30 fungal antagonists on two nutrient media (potato sucrose and Rudakov's) established 14 strains with one or more types of mechanisms of antagonistic action against the dry rot pathogen. 7 strains had a double mechanism of action (competitionfor feeding area and hyperparasitism). Of these, six strains (T-1, T-2, T-3, Т-4, Т-5 Trichoderma sp., and А-1 Basidiomycota) showed activity on both media. The growth area of these strains was 100%, with hyperparasitic area sizes ranging from 35.3 ± 0 to 43.4 ± 2.2 cm2. We observed the maximum hyperparasitic zone in the strain A-1 Basidiomycota – 43.4 ± 2.2 cm2 on the potato sucrose medium and 40.2 ± 4.5 cm2 on the Rudakov's medium. We observed the maximum sterile zone to the dry rot pathogen in the strains Xk-2 and Xk-1 Chaetomium olivaceum (5.0 ± 0 and 5.5 ± 0.6 mm) on the potato sucrose medium, and Pbc-1 Penicillium brevi-compactum and Xk-2 Chaetomium olivaceum onthe Rudakov's medium (3 ± 0 mm). [ABSTRACT FROM AUTHOR]