Phylogenetic Analysis of Ralstonia solanacearum Strains from the Main Disease Identification Nurseries in China

In order to explore the phylogenetic relationships of Ralstonia solanacearum strains in the disease identification nurseries of tobacco bacterial wilt in different regions, 100 Ralstonia solanacearum strains isolated from diseased tobacco plants and soil samples were analysed by using the phylotype classification schemes. The phylogenetic analysis results showed that all the isolates can be classified into 4 sequevars, including sequevar 15, 17, 34, and 54. Among them, the isolates from Guangnan, Wenshan, Yunnan were sequevar 17 and 54, the isolates from Taining, Fujian were sequevar 34, the isolates from Sanyuan, Sanming, Fujian were sequevar 15 and 34, the isolates from Baiyun, Guangdong were sequevar 15 and 17, the isolates from Nanxiong, Guangdong were sequevar 15, 17 and 34, the isolates from Xuanzhou, Xuancheng, Anhui were sequevar 34 and 54, the isolates from Fuquan, Guizhou were sequevar 17, and the isolates from Pengshui, Chongqing were sequevar 17. It was found that there were multiple sequevars in the same disease nurseries, and the sequevar of isolates from diseased plants were not consistant with the isolates from soil in the same disease nurseries.