Antifungal activity of Neowestiellopsis persica against Rhizoctonia solani in root and crown of Faba bean cultivated under modified BG-110 medium composition

Rhizoctonia solani, a fungal pathogen, affects the quality and yield of Faba bean crops and hinders plant export. Chemical fungicides effectively control fungal pathogens, but their long-term use harms the environment, soil properties, and human health. Cyanobacteria, a promising source of natural bioactive compounds, have shown efficacy against the fungal colony growth of various plant pathogens, highlighting the need for sustainable practices. As a result, this study examined the biological control of the Rhizoctonia solani disease that affects the Faba bean's root and crown. Disease assessments were then done in five groups: (1) healthy control; (2) control infected with Rhizoctonia solani and not treated with cyanobacterial extract; (3) plant infected with Rhizoctonia solani and treated with cyanobacterial extract suspension of 0.02, (4) 0.04, and (5) 0.08 g/L phosphate during 20 and 34 days. The results of the antioxidant activity by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay showed that with increasing phosphate concentration, the activity increased significantly. The results of enzymatic activity indicated that time did not significantly impact the enzymatic activity of glutathione peroxidase (GPx), catalase (CAT), and guaiacol peroxidase (GPX), with the highest and lowest activity being related to codes 2 and control, respectively. However, time had a significant effect on superoxidase dismutase (SOD) activity, with the highest activity reported on day 35. Moreover, the results showed that increasing the concentration of the extract significantly decreased cell viability in hepatoblastoma (HepG-2) cell lines. The cyanobacterial extract treatment caused over 66 % damage to plants infected with Rhizoctonia solani. The overall results indicated that Neowestiellopsis persica, grown under higher phosphate concentrations, can be used as an effective antifungal biocontrol against Rhizoctonia solani in Faba bean roots and crowns.