Together with seed companies and the Netherlands Food and Consumer Product Safety Authority (NVWA), Naktuinbouw conducted research into the spread of pospiviroids through infected seed. The results demonstrate that the risk of spreading PSTVd and other pospiviroids through seeds is negligible to very low. The spread of these pospiviroids through infected plants and fruits is far more probable.
Over 100,000 seeds of five heavily infected seed lots were sown and pricked out to see whether transmission via seed occurred. Harrie Koenraadt, R&D researcher on the study: “After about two months of growth, one young leaf was taken from each plant and tested for the presence of pospiviroids. No transmission via seed was shown in this large-scale study."
Potato spindle tuber viroid (PSTVd)
PSTVd is a major and very harmful seed transmissible pathogen of potato, tomato and sweet pepper plants and is one of the pospiviroids. Harrie Koenguit: “Using highly sensitive molecular detection techniques we could easily demonstrate the presence of PSTVd and other pospiviroids on sweet pepper and tomato seeds. This will reduce the number of infected seed lots in the market and limit the risk of spreading PSTVd through infected seed.” It seems highly likely that the role of infected seed in the spread of pospiviroids in sweet peppers and tomatoes in practice is vastly overestimated.
Read the article that Harrie Koenraadt and his R&D colleagues contributed to on the MDPI website.