Santosh Kumar Sethi* and Arup Kumar Mukherjee
Molecular Plant Pathology, Division of Crop Protection, ICAR-National Rice Research Institute, Cuttack, India.
Different Bacillus strains were isolated and selected to assess their capability to inhibition of rice soil borne pathogens and evaluated in terms of plant growth promotion activities. Out of seventeen strains, four strains B-1, B-2, B-3 and B-4 showed strongly antagonistic activities against pathogens and showed significant plant growth promoting (PGP) activity. Based on the morphological and several biochemical approaches like P-solubilization, IAA production, HCN production, different specific C-utilization, catalase, oxidase activities and mechanism of antagonism was studied through protease and chitinase activities, all these six isolates were identified as Bacillus sp. All the strains showed strongly inhibited (upto 90%) the growth of phytopathogens like Rhizoctonia solani, Sclerotium rolfsii and Sclerotium oryzae invitro. For Plant growth promoting assay, Strains B-1, B-2 and B-3 were capable of enhancing the vegetative growth and yield parameters (shoot/root length, biomass, chlorophyll content and yield) and showed significant increase than non-inoculated control plants. The present findings suggest that these three indigenous isolates may be exploited as a potential bioinoculant agent for biocontrol as well as plant growth promoter.
Keywords: Bacillus; phytopathogens; Rice; R. Solani; S. Rolfsii; S. oryzae.