The Plant Pathology Journal Open Access Detection of Multiple Potato Viruses in the Field Suggests Synergistic Interac- tions among Potato Viruses in Pakistan

Viral diseases have been a major limiting factor threat-ing sustainable potato (Solanum tuberosum L.) produc-tion in Pakistan. Surveys were conducted to serologi-cally quantify the incidence of RNA viruses infecting potato; Potato virus X (PVX), Potato virus Y (PVY), Potato virus S (PVS), Potato virus A (PVA), Potato vi-rus M (PVM) and Potato leaf roll virus (PLRV) in two major potato cultivars (Desiree and Cardinal). The results suggest the prevalence of multiple viruses in all surveyed areas with PVY, PVS and PVX dominantly widespread with infection levels of up to 50 % in some regions. Co-infections were detected with the highest incidence (15.5%) for PVX and PVS. Additionally the data showed a positive correlation between co-infecting viruses with significant increase in absorbance value (virus titre) for at least one of the virus in an infected plant and suggested a synergistic interaction. To test this hypothesis, glasshouse grown potato plants were challenged with multiple viruses and analyzed for sys-temic infections and symptomology studies. The results obtained conclude that multiple viral infections dra-matically increase disease epidemics as compared to single infection and an effective resistance strategy in targeting multiple RNA viruses is required to save po-tato crop