Abstract
Bacillus subtilis RB14 was used as an antagonist against fungal pathogen Rhizoctonia solani K1 to control damping-off diseases in tomato plants. Tomato seeds were treated with B. subtilis RB14 culture. The concentration of bacterial cells for the treatment was about 108 cfu/ml. Treated tomato seeds showed 99% germination index similar to the untreated seeds. Scanning Electron Microscopic observations showed a clear evidence of the presence of B. subtilis RB14 on tomato seed surface. Clear inhibition zone was observed using treated seed in dual plate assay against R. solani K1. B. subtilis RB14 treated seed showed 80% reduction in disease incidence during in vivo plant experiments. B. subtilis RB14 produces lipopeptide antifungal antibiotic iturin A which could suppress R. solani K1. The phenomenon was supported by our observation where we found significant amount of iturin A from the root zone soil of the seed treated plants.
Highlights
Interest in utilization of biofertilizer and biological control of soil borne pathogens has increased considerably in last few decades worldwide
Pathogenic fungi Rhizoctonia solani K1 was cultivated in potato dextrose broth (PDB) medium containing 200 g/L of potato infusion, 20 g/L of glucose, and 10 g/L of Polypepton and the pH was adjusted to 5.6
When B. subtilis RB14 treated tomato seeds were placed on the potato dextrose agar (PDA) plate containing R. solani mat, clear zone of inhibition was observed (Figure 1(A))
Summary
Interest in utilization of biofertilizer and biological control of soil borne pathogens has increased considerably in last few decades worldwide. (2016) Biocontrol of Rhizoctonia solani K1 by Iturin A Producer Bacillus subtilis RB14 Seed Treatment in Tomato Plants. Bacillus spp. have the characteristics of omnipresence in soils, rapid growth in liquid culture, high thermal tolerant spores, considered as a safe and stable biocontrol agent [6]. Recent advances in microbial and molecular techniques have significantly contributed to introducing many different bacterial genera into soils, onto seeds, roots, tubers or other planting materials to control disease and improve productivity. Bacillus species can offer several advantages over other bacteria because of their ability of producing highly resistant endospores and broad spectrum antibiotics [10]. Iturin A shows significant antifungal activity against phytopathogens, it induces defense responses in plants and reduces disease severity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
