ABSTRACT

Title: Study on screening of rhizobacteria for biological control of grain rot on rice caused by Burkholderia glumae

Grain rot or bacterial panicle blight caused by Burkholderia glumae is important  disease on rice. In Vietnam, the disease reduce 75% yield loss in severe infested field. Disease control based on chemical method cause negative effect on environment and also promote development of resistant strain. This study focus on biological control of the disease using rhizobacteria with  aim to screen promising antagonistic bacteria can inhibit pathogenic bacterium and can control the grain rot disease on rice. In in vitro test, nine  from thirty-six tested  rhizobacteria showed antagonistic ability to B. glumae with inhibition zone from 0.6 -11.8 mm, two strains Pseudomonas fluorescens 28 and  P. fluorescens 44  showed highest inhibition zone. When  apply suspension of these strains  (10⁸cfu/ml)  on rice plant at 2 days before flowering and 5 days after flowering can reduced disease very good and increase yield compared nontreated control in greenhouse conditions.

Keyword: antagonistic bacteria, Burkholderia glumae, grain rot, rice.