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Exploring the Potentiality of Novel Rhizospheric Bacterial Strains against the Rice Blast Fungus Magnaporthe oryzae L.
Published online March 7, 2018
© 2018 The Korean Society of Plant Pathology.

Narayanappa Amruta1*, M. K. Prasanna Kumar2, M. E. Puneeth2, Gowdiperu Sarika1, Hemanth Kumar Kandikattu3, K. Vishwanath, and Sonnappa Narayanaswamy1

1Department of Seed Science and Technology, UAS, GKVK, Bengaluru, Karnataka 560065, India
2Department of Plant Pathology, UAS, GKVK, Bengaluru, Karnataka 560065, India
3Biochemistry and Nanosciences Discipline, Defence Food Research Laboratory, Mysore, Karnataka 570011, India
Correspondence to: Phone) +573-529-2669, FAX) +573-884-7850
Received December 1, 2017; Revised January 5, 2018; Accepted January 30, 2018.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Rice blast caused by Magnaporthe oryzae is a major disease. In the present study, we aimed to identify and evaluate the novel bacterial isolates from rice rhizosphere for biocontrol of M. oryzae pathogen. Sixty bacterial strains from the rice plant’s rhizosphere were tested for their biocontrol activity against M. oryzae under in vitro and in vivo. Among them, B. amyloliquefaciens had significant high activity against the pathogen. The least disease severity and highest germination were recorded in seeds treated with B. amyloliquefaciens UASBR9 (0.96 and 98.00%) compared to untreated control (3.43 and 95.00%, respectively) under in vivo condition. These isolates had high activity of enzymes in relation to growth promoting activity upon challenge inoculation of the pathogen. The potential strains were identified based on 16S rRNA gene sequencing and dominance of these particular genes were associated in Bacillus strains. These strains were also confirmed for the presence of antimicrobial peptide biosynthetic genes viz., srfAA (surfactin), fenD (fengycin), spaS (subtilin), and ituC (iturin) related to secondary metabolite production (e.g., AMPs). Overall, the results suggested that application of potential bacterial strains like B. amyloliquefaciens UASBR9 not only helps in control of the biological suppression of one of the most devastating rice pathogens, M. grisea but also increases plant growth along with a reduction in application of toxic chemical pesticides.
Keywords : antimicrobial, biocontrol agents, rhizosphere, surfactin

February 2018, 34 (1)