Identification of Causing Blackleg of Potato in New York State.

Soft rot bacteria classified in the Pectobacteriaceae (SRP), including and spp., are responsible for soft rot and blackleg diseases of potato. Since 2014, blackleg outbreaks caused by have increased in the United States and Canada. Our previous study found that the most abundant causal organisms of blackleg disease in New York State were and , with the latter being the only species reported. In the present study, we identified and characterized pathogenic SRP bacteria from 19 potato samples collected in New York State during the 2017 growing season. We used genome sequence comparison to determine the pathogens' species. We found eight , one , two , two , and six isolates in our 2017 SRP collection. This is the first time that has been reported to cause potato blackleg disease in New York State. We determined the phylogenetic relationships between the SRP strains by using 151 single-copy orthologous gene sequences shared among the set of bacteria in our analysis, which provided better resolution than phylogenies constructed with the gene.