| Soft rotted disease caused by Erwinia.carotovora is one of the three major diseases of Chinese cabbage. It would be epidemic at large and cause heavy losses, when drought in the earlier stage of cabbage growth and raininess in last period or unreasonable irrigation, so the disease is the important factor to affect the quality and yield of cabbage. Now, the most way of control the disease is combine the breeding variety to chemical control, but the effect is uncomfortable.The most aim of the experiment was isolated and screened the strong antagonistic bacteria against Ecc from the soil of the rhizosphere of Chinese cabbage, and optimised the aimed strain fermented condition, identified the strain.The results showed that:(1) In this study, 254 strains of bacteria were isolated from 7 soil samples, which collected from the rhizosphere soil of Chinese cabbage in various areas in Yangling, Zhouzhi Shaanxi province and Lhasa, Linzhi area in Tibet. A strain had stronger and stable antagonistic effect against many plant pathogens were selected through agar plate experiment, fermented solution plate experiment, and pot experiment.(2) The determination of suppression spectrum by strain L227-3 showed that this bacterial strain possessed a wide inhibiting spectrum. Through indoor experiment, it had a strong antagonistic action to tested pathogens and bacteria, especially to Ophiobolus graminis Sacc.(3) Formed a cut in cabbage leaf and inoculated strain L227-3 on the cut, and then observed the infection of strain L227-3. The results showed that strain L227-3 was avirulent and it would not influence cabbage.(4) The influence on the germination rate of seeds and growth of radicels with strain L227-3 fermented solution was tested by plate growth experiment. The results indicated that the bacterial fermentation had advantaged effects on plant growth. Average length of radicels treated by fermented solution was more than that of CK, and the growth of radicels were stronger accordingly. |
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