Detecting Potato virus Y in massive potato seed lots by using single sprout culture and RT-PCR as an integrated diagnostic method

 In order to minimize the systemic infection in potato seed tubers, annually more than 300 potato seed lots are subjected to laboratory testing for potato viruses in the national potato seed certification system. The accuracy, sensitivity, specificity and speed are of the most important criteria for a diagnostic method to be employed in seed certification laboratory testing procedure. In this study the efficiency of using two methods including single sprout culture and RT-PCR as an integrated diagnostic method was investigated for detecting Potato Virus Y in potato seed samples. According to the present study, RT-PCR performance in Potato Virus Y detection was better than ELISA in terms of sensitivity, accuracy and time saving. RT-PCR successfully detected one infected sample in a combined sample consists of 50 individual samples while ELISA enabled to detect one infected sample in a much smaller combined sample consists of only five subsamples. Moreover because of ELISA retractions to detect low virus concentration and its false negative result, about six percent potato seed lots were incorrectly labeled basic seeds instead of certified seeds. Considering the maximum permissive virus infection percent in national potato seed standards (4% for the lowest seed class) and the maximum required subsamples to be tested (5 subsamples), using RT-PCR method in potato seed certification is economically recommended.