Study On The Biocontrol Of Xanthomonas Campestris By Antagonistic Bacteria

Xanthomonas campestris is one of the most important diseases in citrus. It affects the quality of citrus and also be classified as a drone of quarantine. At present, there is no ideal pesticides to control this disease. The utilization of pesticides not only pollute the environment but also could not meet the demand of security. Thereby, it is of great significance to screen some beneficial microorganisms to control this disease.In this study we collected the Xanthomonas campestris germina specimens from Hengyang and Yongzhou, and we also disscussed its classification and isolation. The results showed that Xanthomonas campestris germina can be easily isolated from the new pathological leaves. after be treated with alcohol for 7-10 seconds.We also collected different citrus varieties from Hengyang, Yongzhou, Changde, Changsha and other areas. Two hundred and third-four strains were isolated from specimens surface, including 225 bacterial strains and 9 fungi strains. 32 strains which could inhibiting the growth of Xanthomonas campestris germina were screened, the effects of strains Kxl5, Kx22, Kx47, Kx48 were more prominent.In the colonization and antagonism experiments, the filtrate liquid from the strain Kx47 had no antagonistic activity and the colonization capacity of the strains Kx22 was weak, so we selected the strains Kxl5 and Kx48 as antagonisitic bacteria in the study.The strains Kxl5 and Kx48 were identified as Gluconobacter sp. and...