New study provides evidence on movement of potato blight pathogen

New North Carolina State University research delves into the movement and evolution of the pathogen that caused the Irish potato famine in the 1840s, which set down roots in the United States before attacking Europe. The study, published in PLOS ONE, shows that a lineage called FAM-1 caused outbreaks of potato late blight in the United States in 1843 and then two years later in Great Britain and Ireland. It was also found in historic samples from Colombia suggesting a South American origin. FAM-1 caused massive and debilitating late-blight disease outbreaks in Europe, leaving starvation and migration in its wake. Jean Ristaino, William Neal Reynolds distinguished professor of plant pathology and the corresponding author of the study, theorizes that the pathogen arrived in Europe via infected potatoes on South American ships or directly from infected potatoes from the United States. More