Development and evaluation of a multiplex RT-PCR for detecting main viruses and a viroid of potato

A multiplex RT-PCR (mRT-PCR) for detecting four potato viruses (Potato virus S (PVS), Potato virus X (PVX), Potato virus Y (PVY), and Potato leaf roll virus (PLRV)) and one potato viroid (Potato spindle tuber viroid (PSTVd)) was developed. The mRT-PCR consisted of one reaction with specific primers designed according to the sequences of coat protein (CP) genes of respective viruses and the sequence of the viroid. The entire procedure from tissue grinding to RT-PCR results takes about 4 hrs. The reliability of the method was tested on leaves sampled from the field, greenhouse and in vitro-grown plants by comparison with double-antibody sandwich ELISA (DAS-ELISA). A high correlation between these two methods was observed. The mRT-PCR was also evaluated by testing infected samples obtained from the International Potato Center, Lima, Peru; this testing confirmed its high reliability and sensitivity.