Genetic diversity of Xanthomonas arboricola pv. pruni strains in Japan revealed by DNA fingerprinting

Xanthomonas arboricola pv. pruni (Xap) strains collected from peach orchards in six areas in Japan were fingerprinted by inter-simple sequence repeat (ISSR)-polymerase chain reaction (PCR) and repetitive sequence-based (rep)-PCR. Although 148 strains were differentiated into four fingerprint groups (A-D), the genetic diversity among the Xap population was low. The pathogenicity of strains belonging to different fingerprinting groups was very similar. These results show that the causal agent of bacterial spot on peach in Japan is genetically nearly homogeneous.