2018 年 2018 巻 65 号 p. 29-31
We investigated whether tomato plants developing with bacterial wilt causes Ralstonia solanacearum contamination of soil and whether resistant rootstock restrains the transfer of the pathogen to soil in the field. In a susceptible rootstock, migration of the pathogen with a bacterial population close to the detection upper limit was confirmed in all plots in the upper layers of soil, and the migration was detected in 2/3 of plots even in deep soil layers. There was no significant difference in the results of a moderately resistant rootstock from those of a susceptible one. In a resistant rootstock, the migration of the pathogen was detected from only a few plots, and the bacterial population was lower by two orders of magnitude compared with those of a susceptible rootstock. However, it was confirmed that the pathogen transferred to the deep layers of soil even from a resistant rootstock.