First Report of the Detection of ‘Candidatus Liberibacter’ Species in Zebra Chip Disease-Infected Potato Plants in the United States

Zebra chip (ZC), an emerging disease causing economic losses to the potato chip industry, has been reported since the early 1990s in Central America and Mexico and in Texas during 2000 (4). ZC was subsequently found in Nebraska, Colorado, New Mexico, Arizona, Nevada, California, and Kansas (3). Severe losses to potato crops were reported in the last few years in Mexico, Guatemala, and Texas (4). Foliar symptoms include purple top, shortened internodes, small leaves, enlargement of the stems, swollen axillary buds, and aerial tubers. Chips made from infected tubers exhibit dark stripes that become markedly more visible upon frying, and hence, are unacceptable to manufacturers. Infected tubers may or may not produce plants when planted. The causal agent of ZC is not known and has been the subject of increased investigation. The pathogen is believed to be transmitted by the potato psyllid, Bactericera cockerelli, and the association of the vector with the disease is well documented (3). Following the report ...