A Hydroponic Inoculation Method for Rapid and Efficient Evaluation of Tobacco Resistance to Bacterial Wilt Disease at Seedling Stage

In order to develop a rapid and effective method for resistance evaluation of tobacco bacterial wilt disease (BWD) at seedling stages, four tobacco varieties including Honghuadajinyuan, Qinggeng, Changbohuang and D101 were selected as materials in this study, and their BWD resistance or susceptibility were evaluated based on the disease index after inoculation of Ralstonia solanacearum with root-undamaged and root-damaged methods in a hydroponic system. The results showed that the BWD resistance/susceptibility for cultivars could be identified at the 7 or 10 days after inoculation by both root-damaged and undamaged inoculation methods, respectively. D101 was middle resistant, Changbohuang was highly susceptible, Honghuadajinyuan was highly susceptible or susceptible, and Qinggeng was susceptible. These results were basically consistent with the resistance evaluation obtained by a traditional root-damaged inoculation method in pot culture experiment, which needed 3 to 4 weeks. These results indicated that the hydroponic inoculation method established in this study was a rapid, efficient and accurate method for evaluation of tobacco BWD resistance/susceptibility at seedling stages.