Potato virus Y (PVY) is one of the most studied pathogens in the seed potato certification system, and recent strain-frequency surveys help refine the diagnostic profile that supports modern certification programmes. A multi-year survey of Estonian seed potato lots covering 1,041 samples across three sampling windows reports that recombinant strains, particularly PVYNTN and PVYN-Wi, are now common in field-collected isolates. Comparable observations have been published from seed lots in Colorado’s San Luis Valley and in Michigan over the same period. For Canadian seed growers preparing 2026 inspections, the practical implication is that strain-aware diagnostic programmes give the most useful certification data.
What the Recent Survey Data Show
The Estonian survey, published in Plant Health Progress, is one of the most current strain-frequency reads available: A Survey of Potato Virus Y Strains in Estonian Seed Potatoes. The Colorado study covering San Luis Valley seed lots reports PVYN-Wi as the leading strain, followed by PVYO and PVYNTN, with rising rates of dual and triple infections in the same samples: Detection and Characterization of Potato Virus Y Strains in San Luis Valley. The Michigan study documents the same recombinant prevalence with measurable tuber necrosis associated with PVYN-Wi isolates: Prevalence of Potato Virus Y Strain Composition Impacting Michigan Seed Potato Production.
Three observations repeat across these datasets:
- Recombinants (PVYNTN and PVYN-Wi) are commonly recovered in seed lots across diverse production regions.
- Mixed infections involving two or three strains are routinely documented.
- Strain composition has shifted compared with surveys from the late 1990s and early 2000s.
Why Strain Identity Is Useful for Certification
Strain identity is informative because tuber phenotype differs by strain. The PVYNTN recombinant is associated with potato tuber necrotic ringspot disease, the brown ring lesions that appear after storage. PVYN-Wi has been associated with tuber necrosis under some conditions, while PVYO is most often linked with leaf-only symptoms. Phytosanitary action benefits from knowing which strain is present, because seed lot fate is partly informed by the projected impact on the next generation of tubers.
A 2021 review describes how PVY emerged from the Andes and went on to become a major pathogen of potato and other Solanaceous crops worldwide: Potato Virus Y Emergence and Evolution.
Layered Diagnostic Programmes Work Well
The most robust certification programmes use layered diagnostics: lateral flow strips for fast field calls, plate-format ELISA for high-throughput screening, and isothermal nucleic acid amplification (such as Agdia’s AmplifyRP XRT) for in-house confirmation and strain-aware reads on positives. Each format plays a distinct role and the formats complement each other.
Three Agdia products map directly onto the three layers of a modern PVY testing programme.
- For a fast field call, the Agdia ImmunoStrip for PVY and PVY-N gives a confirmation in minutes and includes the necrotic strain marker on a single device.
- For dual screening of common potato viruses, the PVX and PVY combined ImmunoStrip simplifies routine scouting.
- For isothermal nucleic acid confirmation in-house, the AmplifyRP XRT for PVY delivers nucleic-acid-level confidence on a benchtop without a thermocycler.
For a complete leaf virus panel that supports certification programmes, complementary kits are available for PVA and PVS.
What makes the AmplifyRP XRT format particularly suitable for certification labs is that it pairs nucleic acid sensitivity with field-deployable simplicity: a single-temperature isothermal reaction, validated sample matrices, results in under an hour, and a visual lateral-flow readout. Labs with limited molecular biology infrastructure can run it without specialised staff.
Practical Recommendations for the 2026 Inspection Cycle
For Canadian seed potato growers and their support labs, four steps map well to current research. First, audit how your laboratory currently distinguishes PVYO from PVYN, PVYNTN, and PVYN-Wi, and align that with the assays you have in stock. Second, build a sampling plan that captures both leaf and tuber tissue from any lot that flags positive in serology, since tuber expression can develop after storage. Third, document mixed infections explicitly, because recent surveys show co-infection is common. Fourth, plan retests on borderline lots so certification calls do not depend on a single ambiguous result.
Field Notes on the AmplifyRP XRT Format
Several practical attributes make Agdia’s AmplifyRP XRT format particularly easy for certification labs to integrate. The reaction runs at a single isothermal temperature on a benchtop, returns a result in under an hour, and reads out visually on a lateral flow device with no specialised instrument required. The validated sample matrix is raw plant tissue with a simple grinding step, which keeps sample preparation straightforward for scouts and technicians. Each kit includes reaction pellets and the buffer set needed for the run, and the format supports same-shift decision-making in seed inspection contexts.
Bottom Line
PVY field populations have shifted over the past two decades, and modern certification programmes benefit from a layered diagnostic toolkit that combines lateral flow strips, ELISA, and isothermal nucleic acid testing. Agdia’s product family covers all three layers in formats that are validated, easy to deploy, and accessible to in-house labs. The diagnostic tools to do this work well are widely available, and adoption is straightforward for any Canadian operation.
Need to support a PVY testing programme with validated, ready-to-use kits? Immunomart stocks the full Agdia potato pathogen lineup for Canadian seed growers and certification labs. Browse Agdia diagnostics for potato.
