​Changing Strain Composition of Potato virus Y (PVY) in the U.S. Potato

August 2019 | 17 min., 50 sec.
by Alexander V. Karasev
University of Idaho


Potato virus Y (PVY) is the most serious problem facing the seed potato industry in the United States and the main cause for rejection of seed potato lots. In addition to affecting seed potato production, PVY reduces yields of commercial potato crops and may reduce the quality of tubers because of necrotic reactions in susceptible cultivars. During the past 10 years, a distinct shift has been observed in the prevalence of recombinant PVY strains associated with tuber damage in U.S. potatoes. This shift has resulted in the virtual disappearance of the nonrecombinant, ordinary strain (dominant until 2012) and the rise of two recombinant strains, which together represent more than 90% of all PVY isolates now circulating in potato. These changes in PVY strain composition in potato fields have important consequences for potato certification, potato-breeding programs, and diagnostic laboratories.

About the Presenter

Alexander V. KarasevAlexander V. Karasev received his PhD in virology from Moscow State University in Russia. After moving to the United States in 1992, he worked on plant virus problems in California, Florida, and Pennsylvania. Since joining the University of Idaho in 2006, Karasev has developed a research program in plant virology focused on viruses of potato in the Pacific Northwest. A major emphasis of this research is on Potato virus Y (PVY), a main virus affecting the potato industry. Karasev’s research during the past 13 years has focused on understanding interactions between plant viruses and their hosts and how resistance genes are driving virus evolution. He has characterized local and global PVY populations, revealing a close link between shifts in virus strain composition in the field and introductions of new, strain-specific resistance genes in newly released potato cultivars. His current efforts are focused on identifying new sources of resistance to PVY and other potato viruses.​

Contact Information:
Email: akarasev@uidaho.edu


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