Identification of potential bacteria controlling pathogenic fungi Rhizoctonia solani in rice

G.H. Tan, M.S. Nordin and A.B. Napsiah

Abstract

This study was to produce highly efficient antagonists to control soil borne plant pathogen Rhizoctonia solani in rice. Soil samples from different location in natural ecosystem were collected and characterization for antagonistic efficiency between isolated bacteria and R. solani were performed. Antagonistic test in dual culture showed that isolates S3B11 and SW2B49 had the highest antagonistic activities with the inhibition zone of 36.0 mm and 32.2 mm on potato dextrose agar (PDA) medium respectively. These two isolates produced chitinase on M9 agar supplemented with colloidal chitin as the sole carbon source. The results indicated that these two strains hydrolyzed colloidal chitin after 3–4 days. The production of chitinase could be one of the factors which suppressed growth of R. solani on the agar medium. From this study, it could be concluded that the two antagonists identified as Pseudomonas fragi and Bacillus pumilus have the potential to control R. solani in rice.

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