Ralstonia solanacearum race 3 biovar 2 strains isolated from pelargonium are pathogenic on potato
In spring 1999, Ralstonia solanacearum (EPPO A2 quarantine pest) was isolated from zonal pelargonium (Pelargonium x hortorum) imported into Wisconsin (US) from Guatemala (since then, other cases have been reported see EPPO RS 03/064). Bacterial strains were isolated from wilted pelargonium from Wisconsin, New Jersey and South Dakota. Physiological tests showed that they belonged to biovar 2 (which is almost synonymous with race 3). When using PCR, race 3 biovar 2 specific primers amplified a DNA fragment of the expected size. It was concluded that bacterial strains isolated from pelargonium belonged to R. solanacearum race 3 biovar 2. Pathogenicity tests showed that these strains were highly pathogenic to potato (and pelargonium) under glasshouse conditions. The presence of R. solanacearum race 3 biovar 2 strains in USA raises concern that the bacterium could move from ornamental plants into potato fields.
Williamson, L.; Nakaho, K.; Hudelson, B.; Allen, C. (2002) Ralstonia solanacearum race 3 biovar 2 strains isolated from geranium are pathogenic on potato.
Plant Disease, 86(9), 987-991.