Soft Rot Induced by Dickeya undicola in Sweet Potato from South America

In 2023, symptomatic sweet potato ( Ipomoea batatas) tubers from South America were intercepted in the Netherlands. The tubers showed maceration of the cortex and vascular discoloration. Pectinolytic colonies were isolated and identified as Dickeya undicola using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS), PCR analysis, and Illumina sequencing. Subsequent pathogenicity tests confirmed that this bacterium was the causal agent of the symptoms. Additional pathogenicity tests showed that this pathogen can also cause damage on potato ( Solanum tuberosum). To our knowledge, this is the first report of this pathogen on sweet potato and the first finding on plant material originating from South America.