Development of a duplex-PCR for differential diagnosis of Xanthomonas phaseoli pv. manihotis and Xanthomonas cassavae in cassava (Manihot esculenta)

Cassava Bacterial Blight and Cassava Bacterial Necrosis are two bacterial diseases affecting cassava, respectively caused by Xanthomonas phaseoli pv. manihotis (Xpm) and Xanthomonas cassavae (Xc). Since both pathogens may be present on leaves and cause similar symptoms, we developed a new molecular diagnostic tool to detect and distinguish between Xpm and Xc. Based on genome sequences from the target species as well as from non-target species, in silico analysis was performed to select candidate primers through a novel strategy targeting specificity. Experimental validation enabled to establish a duplex-PCR diagnostic tool that will be useful for future surveillance programs and better disease control.