Antagonism against phytopathogenic bacteria and fungi and phytoregulating activity of streptomycetes of chernozems Moldova

Two strains of streptomycetes with antimicrobial activity were isolated from the chernozem of the central part of Moldova. The ability of strains to actively inhibit the growth ofphytopathogenic fungi of the genus Fusarium (growth inhibition zone with a diameter of 28.0-34.0 mm), B. cinerea, A. alternata (22.029.0 mm), and S. sp. 9 - completely suppress the growth of S. sclerotiorum and, to a lesser extent, phytopathogenic bacteria (zones of growth inhibition - 14.0-16.0 mm). As a result of the selection, natural variants were found in which antifungal activity and the ability to synthesize substances with phytohormonal activity were determined when cultivated on a liquid complex medium M-I. Natural variants № 2, 6 and 7 of strain S. sp. 9 had the ability to completely suppress the growth of A. alternata, and the growth of S. sclerotiorum - var. № 2, 6, 7 of strain S. sp. 9 and var. 10 strains of S. sp. 12. The stimulating effect of exometabolites of natural variants of the studied strains was established: an increase in the number of roots by 4.6-13.8 % after triticale seeds were treated with aqueous solutions of exometabolites at a concentration of 1:200, the length of roots was 6.8-20.0%, and also the weight of the roots (by 25.0-50.0%) and shoots (by 12.9-14.3%). That is, strains of streptomycetes isolated from the chernozem of the central part of Moldova and their natural variants with high antagonistic properties against phytopathogenic fungi can be recommended as the basis of biological preparations for crop production, and their exometabolites obtained after cultivating the strains on the complex medium M-I, with presowing seed treatment of triticale to enhance the process of rooting.

стрептомицеты, антибактериальная и антифунгальная активность, тритикале, экзометаболиты, корнеобразование, streptomycetes, antibacterial and antifungal activity, triticale, exometabolites, rooting