Abstract
Two hundred and forty-five plant-associated bacteria isolated from soil by techniques including hypocotyl trapping were subjected to screening based on the promotion of resistance to bacterial wilt and growth in tomato. Three isolates, KSR01, KSB07 and KLT08, were selected. When tomato seeds were treated with KSR01, growth was promoted and the disease severity associated with bacterial wilt was significantly reduced compared to that in the untreated control. KSR01 was re-isolated from the stem tissues of tomato subjected to seed treatment with KSR01 at 35 days after treatment, suggesting that KSR01 was endophytic in tomato. KSR01 did not produce antibacterial substances against Ralstonia solanacearum, the pathogen of bacterial wilt. This suggested that the mode of action of KSR01 against bacterial wilt consisted of the induction of resistance. KSR01 was identified as Herbaspirillum huttiensis by fatty acid analysis, 16S rRNA sequence and physiological and biochemical characteristics.
