Multi-year evaluations of an FTA card-based detection protocol for four vector-borne viruses affecting potato

Authors: Ingram, Jason; MATTUPALLI, CHAKRADHAR - Washington State University; MUDRAK, ERICA - Cornell University; CURTIS, MICHELLE - Cornell University; O'NEILL, PATRICK - Soil Health Services; DAVENPORT, BRYANT - Agdia; GUDMESTAD, NEIL - North Dakota State University; CHARKOWSKI, AMY - Colorado State University; GROVES, RUSSELL - University Of Wisconsin; BABLER, BROOKE - University Of Wisconsin; FROST, KEN - Oregon State University; KARASEV, ALEXANDER - University Of Idaho; GRAY, STEWART - Retired ARS Employee; Whitworth, Jonathan; Filiatrault, Melanie

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2025
Publication Date: 4/28/2025
Citation: Ingram, J.T., Mattupalli, C., Mudrak, E., Curtis, M., O'Neill, P., Davenport, B., Gudmestad, N., Charkowski, A., Groves, R., Babler, B., Frost, K., Karasev, A., Gray, S., Whitworth, J.L., Filiatrault, M.J. 2025. Multi-year evaluations of an FTA card-based detection protocol for four vector-borne viruses affecting potato. Plant Disease. https://doi.org/10.1094/PDIS-11-24-2453-RE.
DOI: https://doi.org/10.1094/PDIS-11-24-2453-RE

Interpretive Summary: Potatoes are vegetatively propagated, which increases risk to numerous diseases causing significant losses in quality and tuber yield. To monitor potato viruses, seed potato certification programs visually inspect plants during the growing season and perform time-consuming post-harvest grow-outs in the winter to eliminate seed potato lots with unacceptably high incidences of key tuber-borne diseases. Although these approaches can reduce crop losses, new pathogen detection strategies that are more rapid, sensitive, and accurate are needed to monitor the potato crop for existing and emerging pathogens. Here we compared our direct tuber sampling method combined with a molecular approach to current virus testing methods used by potato seed certification programs. Results showed that direct tuber testing provides reliable results for detecting four potato viruses (potato virus Y (PVY), potato virus S (PVS), potato mop top virus (PMTV), and tobacco rattle virus (TRV)). PVY detection results were comparable to the current seed potato certification tests. Importantly, results were provided to growers approximately three months earlier than the official results from the state seed potato certification programs.

Technical Abstract: To reduce reliance on time consuming post-harvest seed potato grow-outs a Whatman Plantsaver FTA® card-based pathogen detection protocol was developed for four potato viruses (potato virus Y (PVY), potato virus S (PVS), potato mop top virus (PMTV), and tobacco rattle virus (TRV)) from dormant tubers sourced from 10 fields in five U.S. states in 2018 and 2019. Viruses were detected from potato tubers, sprouts, and leaves using different experimental test methods and sample collection timings and when applicable results were compared to the industry standard test method (Leaf-ELISA). When compared to the Leaf-ELISA, accuracy of the Harvest-FTA was 92.9% (PVY) and 93.8% (PVS) and test results were available 90-days earlier than Leaf-ELISA. Results from the Leaf-ELISA for PMTV detection and Leaf-FTA for TRV detection did not agree with the results of all other test methods indicating leaves are a poor test material for detecting these viruses. In 2020, an on-farm collaboration resulted in field implementation of the FTA card-based tuber test for detecting PVY, PMTV, and TRV from eight seed lots. Accuracy, sensitivity, and specificity for detecting PVY from these eight seed lots using the Farm-FTA Test Method were 89%, 92%, and 87%, respectively, and the results were provided approximately three months earlier than the official results from the state seed potato certification programs. Cost analysis of the FTA card-based detection protocols showed that this approach reduced testing costs for multiple pathogens and allowed growers to use a single sampling pipeline to measure and manage multiple pathogen risks at lower costs.