First report of snow bush wilt caused by Ralstonia pseudosolanacearum (Ralstonia solanacearum phylotype I) in Taiwan

In 2019, an unknown wilting disorder on snow bush (Breynia disticha) was observed in Changhua County, Taiwan. Symptomatic snow bush plants exhibited wilting, necrotic, and vascular discoloration. Two strains Bre-RS1 and Bre-RS2 were isolated from symptomatic tissues. Based on physiological tests and molecular analysis, the two bacterial strains were identified as Ralstonia pseudosolanacearum biovar 4. The pathogenicity tests showed that two isolates belonging to race 1 could infect Phyllanthaceae, Solanaceae, and Convolvulaceae with wound inoculation. This report describes a new bacterial wilt disease of snow bush caused by R. pseudosolanacearum in Taiwan and the world. •The wilting disease of snow bush induced by Ralstonia pseudosolanacearum.•Pectolytic activity exhibited by Ralstonia pseudosolanacearum.•Identification of Ralstonia pseudosolanacearum by physiological and molecular tests.•Broad host range of Ralstonia pseudosolanacearum.