Phenotypic and genetic properties of Brenneria nigrifluens, the causal agent of walnut bark canker disease were studied using a combination of key biochemical tests, analysis of whole-cell protein extracts and genetic fingerprints based on DNA primers corresponding to conserved motifs in bacterial repetitive (repetitive extragenic palindromic, enterobacterial repetitive intergenic consensus and BOX) elements and to the 16s rRNA gene. Phenotypic properties indicated that 11 strains showed a high degree of similarity and <5% of isolates showed different properties such as utilization of dulcitol and inositol. A majority of isolates produced rep-PCR profiles similar (>80%) to a B. nigrifluens reference strain. This study showed that the majority of strains had 0–3 plasmids with estimated sizes ranging 9–32 Kb. Strains were clustered into two and three groups by whole-cell protein analysis and rep- PCR, respectively.
