Isolation and Biological Characteristics of Tobacco Ralstonia solanacearum Bacteriophage

【Objective】Tobacco bacterial wilt a widespread and devastating bacterial disease in southern tobacco production area of China, and there is no effective chemical for the control of such disease. The screening of phage will provide phage resources for the prevention and control of tobacco bacterial wilt in the future.【Method】Soil samples were collected from the tobacco field of Ji'an City, Jiangxi Province, and the bacterial wilt phages were isolated by double-layer plate culture and isolation method and the effects of physical and chemical factors on the activity of phage were further compared. 【Result】Six Ralstonia solanacearum bacteriophages were isolated from the soil of tobacco field in Ji'an City, and numbered as PTb7-1，PTb1521，PTb1553，P1Tb1556，P2Tb1556 and PTb574，among which there were differences in biological characteristics. The results of biological characteristics research showed that the optimum growth temperature for several phages was about 35℃ , the lethal temperature was 55-60℃ and the optimum pH was 5-9, and those phages were sensitiveto ultraviolet, ether and chloroform. However, phage PTb7-1 was only suitable to grow and propagate under acidic environment. Phage P2Tb1556 was not sensitive to ultraviolet and ether, but highly sensitive to chloroform.【Conclusion】There are abundant phage resources in tobacco soil, which is a good source for phage screening. The biological characteristics of the six phages is different. P2Tb1556 phage is not sensitive to ultraviolet light and ether, but sensitive to chloroform.