Bacillus amyloliquefaciens D5 as a biocontrol agent against Cercospora Leaf Spot Disease in Vigna radiata L.

Abstract

Plant Growth-Promoting Rhizobacteria (PGPR) are beneficial microorganisms that inhabit the plant rhizosphere, promoting plant growth and enhancing soil health through various mechanisms. One of the key features of PGPR is their ability to produce secondary metabolites such as siderophores and exopolysaccharides (EPS), which play a critical role in plant growth promotion and biocontrol. Siderophores facilitate iron acquisition, which is essential for plant growth and microbial competition, while EPS contribute to biofilm formation, helping PGPR establish strong root colonization and protect plants from abiotic stress and pathogens. The study highlights the biocontrol potential of Bacillus amyloliquefaciens D5, isolated from soil in Vagadkhol, Bharuch district, India, which was found to produce 75 percent siderophore units of siderophore and 0.7 g of EPS. The isolate demonstrated significant antagonistic activity against Cercospora canescens, achieving 71.4 % fungal growth inhibition, while simultaneously promoting the growth of Vigna radiata by enhancing root colonization. These findings suggest that Bacillus amyloliquefaciens D5 may function as a biofertilizer and biocontrol agent, with the potential to reduce disease severity and improve plant health in agricultural systems.