Abstract
In order to establish an assay for bacterial wilt resistance in vitro for potato plants, we examined the assay conditions of inoculation with Ralstonia solanacearum. The suitable plant stage and bacteria concentration as inoculum were the 4-5 leaf stage and 102 CFU/ml in this assay. The suitable incubation temperature was also 28℃ after inoculation. The validity of this assay was assessed using six cultivars and two breeding lines of potato plants with known resistance to R.solanacearum in field screening. Cultivars（or breeding lines） with fewer dead plants in the assay（lower dead plant rates）had stronger resistance in the field test. In addition, this assay was able to distinguish statistical differences between the resistant cultivars（or breeding lines）and the susceptible cultivars in the field screening. These results suggest that this assay system is effective for evaluating bacterial wilt resistance in potato plants.
