Abstract：Potato (Solanum tuberosum) is one of the most important crops in the world and it can be infected by Potato virus S (PVS), which lead to reduction of quality and yield. The high detection rate of PVS, which can be improved by the sensitive and accurate detection technology, will control the PVS threaten for potato production because its introduction and spread is prevented, and the potato industry can be protected. For developing a sensitive and accurate technique, the droplet digital PCR (ddPCR) primers and probe were designed according to the conserved sequence of PVS coat protein (CP) gene and tested through specificity, sensitivity and reproducibility experiment. The results showed that the established method was specific to PVS, and it could effectively distinguish PVS from the control viruses Potato virus X (PVX), Potato virus Y (PVY), Cucumber mosaic virus (CMV) and Tobacco mosaic virus (TMV), which was same with the result of qRT-PCR. The detection sensitivity of ddPCR was up to 20 copies/μL of RNA which was 10-fold higher than that of qRT-PCR. The standard error of three repeats droplets was less than 1.5% of the total number of droplets, indicating the established ddPCR method had good reproducibility. The ddPCR method established in this study can be used for the accurate detection of PVS and also provides a reference for the accurate detection of other plant viruses.
