Biopotential for Plant Stimulation and Control Phytopathogens, Plant Parasitic Nematodes by Exometabolites of Spretomycetes isolated from Soils of R. Moldova

Strains of Streptomycetes isolated from soils of R. Moldova (National Collection of Non-pathogenic Microoganisms IMB ASM) were tested on germination of tomato seeds (Fakeland Marmande varieties), antibacterial and antifungal activities, and suppression of plant parasitic nematodes. For variety Fakel (R. Moldova) strains Streptomyces sp. 11, Streptomyces sp. 47, Streptomyces sp. 49, Streptomyces sp. 154 and Streptomyces sp. 33 significantly increased germination of tomato seeds at 0.5% and 1% dilutions and stimulated formation of root system. However, germination of seeds of variety Marmande (Belgium) were inhibited by strains exametabolites (EM) at 100%, 75%, 50%, 25%, 10% and 5% dilutionsand there was decreasing incline in suppression from 100% to 0.5% dilutions for all the strains. EM of Streptomyces strains showed antagonistic effect on phytopathogenic bacteria and fungi. All the strains demonstrated capacity to decrease the growth of bacteria (Xanthomonas campestris, Agrobacterium tumefaciens, Clavibacter michiganensis) and fungi (Aspergillus niger, Fusarium solani, F. graminearum and Botrytis cinerea). The delayed zone of growth of phytopathogenic bacteria was 15-23 mm and for fungi 10-15 mm. Among strains of Streptomyces from the National Collection of Non-pathogenic Microoganisms, ASM, isolated from soils of R. Moldova the selected strains (Streptomyces sp. 11, Streptomyces sp. 47, Streptomyces sp. 49, Streptomyces sp. 154 and Streptomyces sp. 33) showed nematicidal activities against the root-knot nematodes (Meloidogyne spp.)