IDENTIFICATION OF SOME BACTERIA FROM PADDY ANTAGONISTIC TO SEVERAL RICE FUNGAL PATHOGENS

The effect of 23 bacterial strains from ricefields in the tropics on r ice seed germination and on radicle and hypocotyl development of four rice cultivars was determined. There was a varietal difference in resp onse to seed bacterization with the different bacterial strains. Germi nation of cv. IR58 increased from 78 to 93 %, that of cv. IR64, from 8 9 to 97 %. Less effects on germination of cvs IR42 and IR36 were obser ved. All strains inhibited the mycelial growth of Rbizoctonia solani i n vitro. The three strains, identified as Bacillus subtilis, inhibited the mycelial growth of eight fungal pathogens whereas the other strai ns were pathogen-specific. Seed bacterization with these bacterial str ains provided a sheath blight protection of 4.5 to 73 % in the glassho use trial. These 23 bacterial strains were identified by phenotypic te sts using the API systems, morphological and biochemical features, and by comparison of electrophoretic patterns after sodium dodecyl sulpha te polyacrylamide gel electrophoresis. Bacterial strains were identifi ed (number of strains in brackets) as: Bacillus subtilis (3), Bacillus laterosporus (1), Bacillus pumilus (1), Pseudomonas aeruginosa (7), P seudomonas belonging to section 1 (5), Erwina herbicola-like (1), and Serratia marcescens (1). The features of the other four strains were s imilar to Serratia except for the DNAase and lipase activities.