Pathogenicity, phylogenomic, and comparative genomic study of <i>Pseudomonas syringae</i> sensu lato affecting sweet cherry in California

Comprehensive identification of phytopathogens and an in-depth understanding of their genomic architecture, particularly virulence determinants and antibiotic-resistant genes, are critical for several practical reasons. These include disease diagnosis, improved knowledge of disease epidemiology, pathogen diversity, and determination of the best possible management strategies. In this study, we provide the first report of the presence and pathogenicity of genomospecies <i>Pseudomonas cerasi</i> and <i>Pseudomonas viridiflava</i> in California sweet cherry. More importantly, we report a relatively high level of resistance to copper among the population of <i>Pseudomonas syringae</i> pv. <i>syringae</i> (47.5%). This implies copper cannot be effectively used to control bacterial blast and bacterial canker of sweet cherries. On the other hand, no isolates were resistant to kasugamycin, an indication that kasugamycin could be effectively used for the control of bacterial blast and bacterial canker. Our findings are important to improve the management of bacterial blast and bacterial canker of sweet cherries in California.