P-602 - Biological and Molecular Characteristics of Potato Viruses in Taiwan and the Evaluation of High-Temperature Effects on Viral Infections

The potato (Solanum tuberosum subsp. tuberosum) is one of the most important staple food crops globally. However, the potato industry faces significant challenges due to viral diseases including potato leafroll virus (PLRV) and potato virus A, S, X, M and Y (PVA, PVS, PSX, PVM and PVY). In this study, we investigated the presence of potato viruses in samples collected from major potato fields in Taiwan. Among total 150 samples, only PVY and PVS were detected and both single infection (PVY:42% and PVS:2%) and co-infection (PVY+PVS:19%) existed. Total 10 PVY isolates and one PVS isolate were selected for the pathogenicity assay. We found that PVY-33 isolate caused severe stunting and leaf deformation symptoms in the Nicotiana benthamiana and it led to a reduction in potato plant weight. Virus strain-typing analysis showed that the PVY-33 isolate belonged to the PVY^N-Wi strain, while PVS-67 belonged to the PVS^O strain. We also analyzed the high-temperature effects on PVY and PVS infections in two potato cultivars, Kennebec and Tainung No. 1. We found that high temperatures led to an increase in PVY and PVS accumulation in Kennebec. For the Tainung No. 1, high temperatures led to an increase in PVS accumulation but decreased the accumulation of PVY, suggesting that Tainung No. 1 exhibits a different immune response to PVY and PVS. Our results provide valuable insights for future potato virus disease management and coping with climate change threats. Subsequently, resistance genes in Tainung No. 1 against PVY infection could be identified for disease-resistant breeding.