Isolation of bacteriophages from Pseudomonas syringae pv. tabaci and their control efficiency against tobacco wildfire disease in pot experiments

To control tobacco wildfire disease in fields, bacteriophages (T-109 and T-ZD) were isolated and purified from Pseudomonas syringae pv. tabaci 109 and ZD respectively. The control effects of T-109 and T-ZD on tobacco wildfire disease were analyzed by needle puncturing inoculation and spray inoculation in pot experiments. The results showed that:1) In needle puncturing inoculation, the control efficiencies of spraying no-diluted T-109 or T-ZD first and then inoculating P. syringae pv. tabaci 109 or ZD on P. syringae pv. tabaci reached 98.64% and 96.68%, respectively. The treatments of spraying 10-fold diluted T-109 or T-ZD first and then inoculating P. syringae pv. tabaci 109 or ZD showed a control efficiency of 97.18% and 95.12%, respectively, and those of inoculating P. syringae pv. tabaci 109 or ZD first and then spraying no-diluted T-109 or T-ZD were at 63.26% and 8.47%, respectively. The treatments of inoculating P. syringae pv. tabaci 109 or ZD first and then spraying 10-fold diluted T-109 or T-ZD had an efficiency of 29.41% and 5.42%, respectively. The treatments of spraying bacteriophages first and then inoculating P. syringae pv. tabaci were better than those of inoculating P. syringae pv. tabaci first and then spraying bacteriophages. 2) In spraying inoculation, the control efficiencies of spraying no-diluted T-109 or T-ZD first and then inoculating P. syringae pv. tabaci 109 or ZD on P. syringae pv. tabaci were 27.32% and 39.44%, respectively. The treatment efficiency of spraying 10-fold diluted T-109 or T-ZD first and then inoculating P. syringae pv. tabaci 109 or ZD were -2.69% and 56.05%, respectively. The treatment efficiency of inoculating P. syringae pv. tabaci 109 or ZD first and then spraying no-diluted T-109 or T-ZD were 0.44% and 36.06%, respectively. The treatments of inoculating P. syringae pv. tabaci 109 or ZD first and then spraying 10-fold diluted T-109 or T-ZD were 28.23% and 23.79%, respectively. No significant difference was found in the control efficiencies between the treatments of spraying bacteriophages first and then inoculating P. syringae pv. tabaci and the treatments of inoculating P. syringae pv. tabaci first and then spraying bacteriophages.