Detection of Ralstonia solanacearum in potato tubers by polymerase chain reaction

A new polymerase chain reaction (PCR) assay was developed for the detection of Ralstonia solanacearum in potato tubers. The designed primers PS-1/PS-2 based on the sequence data of the 16S rRNA gene. Using the optimized PCR p rotocol, it was possible to detect R. solanacearum cells artificially added to concentrated potato extracts in the range of 1-10 colony-forming units (CFU) per PCR reaction mixture (10-100 CFU/ml potato homogenate). No amplif ication products were obtained, when bacteria belonging to other species or genera were submitted to PCR under the same conditions. A total of 10 diff erent DNA extraction methods were adapted for the isolation of R. solanacea rum DNA from potato homogenates and were compared for their suitability as pre-PCR procedures.