Endophytic Streptomyces Strains for the Biocontrol of Rhizoctonia solani and Growth Promotion in Fagopyrum esculentum

Abstract

Soil-borne pathogens pose a significant threat to crop productivity, necessitating sustainable and biologically driven management strategies. This study evaluates the potential of endophytic Streptomyces strains for the biocontrol of Rhizoctonia solani and their role in promoting growth of Fagopyrum esculentum. Endophytic isolates were obtained from healthy plant tissues and screened for antagonistic activity against the pathogen under laboratory and greenhouse conditions. Selected strains exhibiting strong inhibitory effects were further assessed for plant growth-promoting traits, including nutrient solubilization, phytohormone production, and enhancement of root development. The results demonstrated that specific Streptomyces strains significantly suppressed the growth of Rhizoctonia solani, reducing disease incidence and severity in treated plants. Concurrently, inoculated plants showed improved germination, biomass accumulation, and overall vigor compared to untreated controls. Enhanced root architecture and nutrient uptake contributed to better plant establishment and resilience. The dual functionality of these endophytes, combining disease suppression with growth promotion, highlights their potential as effective bioinoculants in sustainable crop production systems. While analytical tools were used to evaluate microbial interactions and plant responses, the primary focus remained on plant–microbe relationships and agronomic benefits. The findings underscore the importance of harnessing beneficial microorganisms to reduce dependence on chemical inputs and improve crop health. This research contributes to environmentally sustainable agriculture by advancing biological control strategies that enhance productivity and maintain soil ecological balance.