Molecular characterisations of Pseudomonas syringae pv actinidiae strains isolated from the recent outbreak of bacterial canker on kiwifruit in Italy

Pseudomonas syringae pv actinidiae (Psa) is the causal agent of bacterial canker on kiwifruit a disease that affects both Actinidia deliciosa and A chinensis This disease has been reported in Japan Korea and Italy It has never been found in New Zealand An outbreak of bacterial canker on kiwifruit has been recently reported in Latina Italy Strains isolated from this outbreak were compared with strains isolated from Japan Korea and strains isolated from Italy in 1992 The specificity of the primers PsaF1/R2 and their usefulness in identifying strains of Psa were confirmed in this study Fingerprinting by BOXPCR allowed the distinction of strains of Psa tested from strains of the closely related pathovar theae However two different profiles were obtained for strains of Psa Two haplotypes for the housekeeping gene cts (gltA) were also found among strains of Psa Such variability might be used for further epidemiological studies