コンポスト添加土壌から調製した微生物懸濁液が養液栽培におけるトマト青枯病の発生に及ぼす影響

摘要

We investigated the effect of a microbial suspension prepared from compost-amended soil on the developmentof bacterial wilt disease of tomato caused by Ralstonia solanacearum in a hydroponic system under greenhouseconditions. When the compost-amended soil suspension was applied to the root zone of tomato seedlings and to thenutrient solution before and after transplanting, respectively, the disease was slightly suppressed. The effect wasenhanced by using a bacterial group, which was incubated in bouillon medium after collection from a compostamendedsoil suspension before application. The population of R. solanacearum in the nutrient solution treatedwith the soil bacterial group remained lower than in the untreated control. In the rhizoplane of tomato plants at 4weeks after treatment with the bacterial group, the total microbial activity evaluated by fluorescein diacetatehydrolysis was higher than those in the control plants and PCR-DGGE analysis showed that a unique bacterialcommunity different from control plants was established. These results indicated that the bacterial group activatedand diversified by compost amendment led to the disease suppression and that these bacteria could be suitable forthe control of bacterial wilt of tomato in hydroponic systems.