Changes in prevalence of potato virus Y strains circulating in potato in the Pacific Northwest, 2011-2021
Date & Time
Tuesday, July 19, 2022, 1:15 PM

Potato virus Y (PVY) is currently the main reason for potato seed lot rejections, also it reduces yield and tuber quality in commercial potato production. The virus exists as a complex of strains and changes in their prevalence were investigated in potato fields in the Pacific Northwest (PNW), including seed potato production systems in the state of Idaho, and commercial potato fields in the Columbia Basin of Washington State between 2011-2021. Between 2011 and 2016, the prevalence of the ordinary, PVYO strain in seed potato dropped 8-10 fold, concomitantly with the rise of recombinant strains PVYN-Wi and PVYNTNa, which together accounted for 98% of all PVY-positives in 2021. No PVYO isolates were found in Columbia Basin trials in 2021, with another recombinant, PVYN:O staying under 2%. In Idaho seed potato, PVYNTNa strain associated with the potato tuber necrotic ringspot disease (PTNRD) was found to increase three-fold between 2011-2019, accounting for 24% of all PVY-positives in 2019. Two other PTNRD-associated recombinants, PVYEu-N and PVY-NE11, were recorded in the PNW between 2012-2016, but both had disappeared from the PNW potato by 2019. Whole genome sequence analysis of the PVY-NE11 suggested this recombinant was introduced in the U.S. at least three times. The data on PVY strain abundance in the PNW potato crops suggest that virus management strategies need to consider the current dominance of the two recombinant PVY strains, PVYN-Wi and PVYNTNa.

Session Type
Parent Session
7/19 - Concurrent Sessions G