Studies On Pathogen Profiles And Epidemiology Of Citrus Canker Disease In Guangxi

Citrus bacterial canker disease is an important and quarantine disease in citrus industry of the world. The pathogen Xanthomonas axonopodis pv. citri is the chief pathogen infects Citrus , Poncirus and Fortunella species of family Rutaceae. The strains of Xanthomonas axonopodis pv. citri were identified as Asiatic type in Sichuan and Fujian provinces of China. The present study focused on the epidemiology of citrus bacterial canker which had happened very common in Guangxi.The strains of X. axonopodis pv. citri were isloated from lesions on C. hongxinensis, C. tianensis, C. huaensis and C. liuensis in Hepu area, C. xiaensis in Yongfu area, C. grandis in Zhongshan area, C. qiensis in Yangshuo area, and C. hongjiangensis, C. xinhuiensis, C .niuherensis, C. jinensis, C. bingtangensis and C. grandis in Gongcheng area, respectively. It was found that Xanthomonas axonopodis pv. citri could be efficiently isolated from the lesions under 5mm in diameter, but the bacterial population was relatively lower in the lesions above 10mm in diameter. The back inoculation of the isolates on C. hongjiangensis in greenhouse produced the typical symptoms of Asiatic citrus canker.Thirteen strains of X. axonopodis pv. citri were tested on 52 physiological and biochemical characteristics. The differences were recorded in utilization of acetate, fructose, citrate, rhamnose, xylose, sucrose, maltose,...