PVY (Potyviridae: potyvirus) is one of the most important potato virus affecting seed potato production and also it is transmitted non-persistently via aphids. For healthy seed potato production, a virus detection system is highly important in addition to aphid monitoring and control. To achieve this detection method, it need to fast and easy to use. About two decades ago RT-PCR based PVY detection method was developed. However that was very time consuming and has low sensitivity. Here, we developed an advanced PVY detection method which a uses the boiling extraction of the viral RNA from aphid stylet and amplification by specific primers located in the viral capsid protein gene. Therefore, it could directly synthesize cDNA of PVY viral capsid gene from extracted RNA of PVY using one-step RT-PCR method in very short time compared to previous methods due to the omission of RNA extraction step. We confirmed this PVY detection method using the two aphid species (Macrosiphum euphorbiae and Aphis gossypii) that known as PVY vectors. The efficiency of this PVY detection method was 60% to 80% from two the aphid species. Hence, this method could be potentially applied to virus free seed potato production programs.

Potato virus Y (PVY) and potato leafroll virus (PLRV) are among the most damaging potato viruses and prevalent in most potato growing areas. In this study, cryopreservation was used to eradicate PVY and PLRV using two cryogenic methods. Potato shoot tips proliferated in vitro were cryopreserved through droplet-vitrification and encapsulation-vitrification using plant vitrification solution 2 (PVS2; 30% glycerol + 15% dimethyl sulfoxide + 15.0% ethylene glycol + 13.7% sucrose) and modified PVS2. Both cryogenic procedures produced similar rates of survival and regrowth, which were lower than those from shoot tip culture alone. The health status of plantlets regenerated from shoot tip culture alone and cryopreservation was checked by reverse transcription-polymerase chain reaction. The frequency of virus-free plants regenerated directly from highly proliferating shoot tips reached 42.3% and 48.6% for PVY and PLRV, respectively. In comparison, the frequency of PVY and PLRV eradication after cryopreservation was 91.3~99.7% following shoot-tip culture. The highest cryopreserved shoot tip regeneration rate was observed when shoot tips were 1.0~1.5 mm in length, but virus eradication rates were very similar (96.4~99.7%), regardless of shoot tip size. This efficient cryotherapy protocol developed to eliminate viruses can also be used to prepare potato material for safe long-term preservation and the production of virus-free plants.