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

Abstract

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 PsaFl/R2 and their usefulness in identifying strains of Psa were confirmed in this study. Fingerprinting by BOX-PCR 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.