Developing a multiplex real-time RT-PCR for simultaneous detection of Pepper chat fruit viroid and Columnea latent viroid

Abstract

Tomato (Solanum lycopersicum L.) is one of the most important vegetables in the world and Asian countries are the center for hybrid tomato seed production. Seed-borne diseases, if not managed well through effective seed health assay, could seriously hamper the global seed trade. Pepper chat fruit viroid (PCFVd) and Columnea latent viroid (CLVd) are two emerging and economically important pospiviroid species infecting tomato and other solanaceous crops. With their greater sequence diversity from those of other common tomato-infecting pospiviroids, it is necessary to develop a new detection method that could effectively detect PCFVd and CLVd, useful for seed health assay. In the present study, we developed a multiplex real time (quantitative) reverse transcription-polymerase chain reaction (qRT-PCR) to detect PCFVd and CLVd in a single tube, thus to save time and money. Using known viroid-contaminated seeds, this multiplex qRT-PCR could detect CLVd and PCFVd from a single contaminated seed, suggesting its sensitivity for seed health assay. The effectiveness of this newly developed multiplex qRT-PCR for detection of PCFVd and CLVd was validated using field-produced tomato plant tissue or commercial tomato seeds.