Screening of Plant Immune Inducer Against Tobacco Bacterial Wilt and Determination of Its Control Effect

Objective In order to explore the plant immune inducers which can be used to control tobacco bacterial wilt, the antibacterial activity and control effects of four kinds of inducers were screened and determined.

Method The control effects were determined and analyzed by using plate inhibition method and potted plant experiments, and the control effects of different plant immune inducers against tobacco bacterial wilt were studied through the determination of minimum inhibition concentration(MIC)and minimum bactericidal concentration(MBC)value.

Result Amino-oligosaccharin and NANO ZnO showed a certain inhibitory effect on Ralstonia solanacearum in the plate tests. The 5 000 μg/mL amino-oligosaccharin had the best antibacterial effect with the inhibition zone diameter of 35.2 mm, and its MIC and MBC were 1 000 μg/mL and 2 000μg/mL, respectively. Different concentrations of Zhinengcong and Atarin did not show any inhibitory effect. However, the potted plant experiments showed that Zhinengcong had the best prevention and control effect on bacterial wilt. The disease entered the peak period on the 10th day after inoculation, and the control effect reached 57%, which was significantly higher than the 37% control effect of streptomycin treatment in the same period. Moreover, Zhinengcong treatment could delay the occurrence of the disease. The control effect of amino-oligosaccharin with significant antibacterial effect on the plate was only 13%, and the control effects of NANO ZnO and Atarin were 3% and 15%, respectively, with poor control effects.

Conclusion Plant immune inducer Zhinengcong had a great potential for biocontrol and can be used for green prevention and control of tobacco bacterial wilt.