Antibacterial effect of Bradyrhizobium spp., Pseudomonas spp., and Bacillus subtilis against pathogenic fungus Rhizoctonia solani on peanut plant

Abstract

Background: Microorganisms such as fungi, bacteria, viruses, and nematodes are integral parts of agro-ecosystems. Some of them are harmful to plant pathogens, whereas, others are neutral or beneficial in their effects on plant growth. The total agricultural losses of economic crops which amount to about 50–75% are caused by soil-borne pathogenic fungi of Rhizoctonia
spp., Fusarium spp., Verticillium spp., Sclerotinia spp., Pythium spp. And
Phytophthora spp. The losses are due to seed rot, root rot, and wilt diseases in different crop fields and greenhouses

Aimes: the present study aimed to evaluate the antagonistic effect of the studied bacteria i.e., Pseudomonas fluorescens, Pseudomonas chlororaphis, and Bacillus subtilis were tested against three tested isolates of R. solani
Methods: The biocontrol tests were carried out using fungal and bacterial bioagents. The tested fungal bioagents were three isolates of Trichoderma
viride. culture collection, three isolates for Rhizoctonia spp were Previously obtained from peanut plants with diseased roots. The bacterial antagonistic include one isolate of Bacillus subtilis and one isolate of Pseudomonas
fluorescens.
Results: Showed that Bacillus subtilis had the highest suppression effect (100%) with the three tested isolates of Rhizoctonia solani compared to
Pseudomonas fluorescens and P. chlororaphis.