The Distribution and Species of Antagonistic Bacteria Against Sheath Blight in Rice Ecosystem

Seven hundred bacterial strains were isolated from diseased or healthy rice plant in Laguna Provinceof Philippines, and then were tested at gram reaction, antagonistic and pathogenicity. There were a lot of G~-, antagonistic and non-pathogenetic bacteria in the rice ecosystem. Antagonistic bacteria isolated from diseased riceplant and at milking to maturity stage were more than that from healthy rice plant and at maximum tillering to flowering stage. Two hundred bacterial strains of them were identified for their species by Biolog. There were 13 genera, 39 species in the 147 G~- bacteria and 8 genera,39 species in the 48 G~+ bacteria occurred in rice ecosystem. In 195identified bacteria, 20 isolates possessed stronger antagonistic ability and distributed in 7 genera and 12 species.