Potato Virus Y (PVY) continues to challenge potato growers worldwide, threatening yield and quality. A newly published study in the American Journal of Potato Research sheds light on resistance mechanisms in three potato cultivars—Payette Russet, Dark Red Norland, and Chieftain—offering valuable insights for both researchers and growers.
Key Findings:
1. Payette Russet: A Standout in Broad-Spectrum Resistance
Payette Russet demonstrated immunity to all tested PVY strains, including:
PVYᴼ (ordinary strain)
PVYᴺᴛᴺ (tuber necrotic strain)
PVYᴺ−Wi (widely prevalent recombinant strain)
PVYᴱᵘ−ᴺ (European non-recombinant strain)
Researchers confirmed that no PVY isolates were able to replicate in Payette Russet, underscoring the effectiveness of its Rysto gene, a known resistance gene derived from Solanum stoloniferum. This highlights the potential of Payette Russet as a strong candidate for breeding programs aiming to develop PVY-resistant varieties.
2. Dark Red Norland and Chieftain: Partial but Strain-Specific Resistance
Both cultivars exhibited a hypersensitive resistance (HR) response, meaning they developed localized necrotic lesions when infected but were not immune. Specifically:
They showed resistance to PVYᴼ and PVYᴺᴛᴺ.
They had partial resistance to PVYᴺ−Wi, with some systemic spread.
They were fully susceptible to PVYᴱᵘ−ᴺ.
This suggests that these cultivars possess N genes, which provide resistance but are strain-specific and temperature-sensitive.
3. Implications for Breeding & Grower Adoption
Payette Russet’s broad-spectrum resistance makes it a valuable resource for breeding future resistant cultivars.
Dark Red Norland and Chieftain may be useful in breeding programs for managing specific PVY strains, but they do not offer complete protection.
Pyramiding resistance genes (combining multiple resistance genes) may be necessary to achieve long-term PVY management.
Why This Matters
PVY remains a major concern for seed certification programs and commercial potato production, as it spreads through aphids and infected seed tubers. This research reinforces the need for strategic variety selection to mitigate disease risks and ensure sustainable potato farming.
Looking Ahead
With Payette Russet proving to be an exceptionally resistant cultivar, future breeding efforts could focus on integrating the Rysto gene into more commercially viable potato varieties. At the same time, continued monitoring of PVY strain evolution is essential to stay ahead of emerging threats.
For growers, the takeaway is clear: Selecting PVY-resistant cultivars like Payette Russet can significantly reduce disease pressure and reliance on chemical control methods.
👉 To read the full study, check out the publication in the American Journal of Potato Research.
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