Abstract
Pseudomonas glumae strains showed different antibiotic activities against P. solanacearum depending upon kind of media used. When triphenyl tetrazolium chloride medium (TTC medium) was used, all strains of P. glumae formed growth inhibition zones around their colonies on the lawn of P. solanacearum used as indicator. Pre-treatment of the roots of tomato seedlings with the suspension of antibiotic productive strains of P. glumae suppressed the severity of wilt incited by challenge inoculation with P. solanacearum. The disease suppression was positively correlated with length of dipping time and concentration of the bacterial suspension used for pre-treatment. Dipping of the roots of tomato seedlings into the bacterial suspension of ca. 1010cfu/ml for 24hr showed highest suppressiveness. The pre-treatment of tomato roots with non-antibiotic-producing strain or heat-killed cells of P. glumae also showed protection, suggesting that some mechanisms other than antibiotic productivity were involved in the suppression of the disease.
