| Bacterial wilt of tomato coused by Ralstonia solanacearum is an important disease which distributes widely in the world. It is very difficult to control the disease because the pathogen is soil-borne and vascular parasite. Plant endophytic bacteria have some superior biocontrol agents to control plant disease and it could increase effect when co-operative with other measures. In this study, the possibility of combination between SA/OS and endophytic antagonistic bacteria 01-144, as well as the mechanism of disease-control was investigated.1. The growth and the pathogenicity of R. solanacearum was not affected by five concentrations ranged from 0.5 mmol-L'1 to 4 mmol-L"1 of salicylic acid not only in vitro but also in greenhouse. SA 2 mmol-L'1 showed the most significant and stable of control efficacy among these five concentrations, especialy with the method of irrigating and spraying instead of other methods of root-soaking, irrigating, spraying and spraying after soaking. After 25 d, the control efficacy was 37.93%. So the ability of SA to suppress the disease meight be related to the induced resistance. Furthermore, the ability did not improve with the increasing of dendity, oppositly, the dangerous caused by SA to plant would increase.2. The growth of R. solanacearum was inhibited by 4 concentrations of OS diluted from 200 times to 800 times in inhibitory examination in vitro, and 500 times was the minimum inhibition concentration (Cmic) of OS to R. solanacearum. The control efficacy of 200 times and 400 times reached 46.43% and 39.29%, respectively, with the method of irrigating and spraying instead of other methods of root-soaking, irrigating, spraying and spraying after soaking in greenhouse.3. The growth, shape and pathogenicity of antagenistic bacteria 01-144 was not affect by SA not only in vitro but also in greenhouse. The biocontrol efficacy of 01-144 against R. solanacearum increased 31.25% and 18.76% when mixed with SA 2 mmol-L/1 and 3 mmol-L"1, respectively.
|
PDF Full Text Request