Patrycja Golińska, Hanna Dahm
Antagonistic properties of Streptomyces isolated from forest soils against fungal pathogens of pine seedlings
Dendrobiology 2013, vol. 69: 87-97
Abstract: Biological control of plant diseases has received worldwide attention in recent years mainly as a response to use of hazardous chemicals in the environment. Soil actinomycetes particularly Streptomyces spp. enhance soil fertility and have antagonistic activity against wide range of soil-borne plant pathogens. In study of antifungal activity of streptomycetes against plant fungal-pathogens Fusarium oxysporum (Schlecht.), F. culmorum (Wm. G. Sm.) Sacc. and Rhizoctonia solani (Kühn) causing damping-off of pine seedlings, in vitro and in vivo tests were carried out. Two types of in vitro tests in mixed cultures of actinomycetes and fungi were performed. In majority of the cases, an inhibitory effect of actinomycetes on fungi was noticed. Three isolates (SG9, SR2, SR4) were highly active against pathogenic fungi and were chosen for exopolysaccharides extraction and in vivo tests. The sensitivity to exopolysaccharide action was noted in fungi from the genus Fusarium. Fusarium oxysporum showed a higher sensitivity to the analyzed exopolysaccharides than F. culmorum. Biocontrol interactions both in sterile and non-sterile soil were found for the actinomycete Streptomyces cyaneus (strain SG9) isolated from root free soil of the pine. The latest experiment confirmed the strong pathogenicity of the fungus Rhizoctonia solani. Antifungal properties of Streptomyces cyaneus (strain SG9) need further comprehensive studies.
Additional key words: Streptomyces sp.; antifungal activity, Fusarium oxysporum, F. culmorum, Rhizoctonia solani, biocontrol activity