ARS | Publication request: Genetic diversity of potato virus Y complex

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 7, 2011
Publication Date: July 1, 2011
Citation: Karasev, A., Gray, S.M. 2011. Genetic diversity of potato virus Y complex. American Journal of Potato Research. DOI: 10.1007/s12230-012-9287-7.

Interpretive Summary: Potato virus Y is the most important disease problem for the U.S. seed potato industry and is responsible for significant reduction in farm income due to regulatory action and rejection of material by trading partners. The seed certification agencies have, in the past, been able to keep the virus below economic threshold levels, but changes in the genetic diversity of the virus are partially responsible for the emergence of several new strains of the virus that cannot be managed using traditional methods. In this paper we examine the changes that have occurred in the virus genome and the impact those changes have had on disease occurrence and type. New information is presented on how these new strains of the virus differ from the typical strains and how regulatory agencies and growers will need to modify practices to manage this new disease.

Technical Abstract: Potato virus Y (PVY) has re-emerged as a significant problem in all potato-producing areas, including North America. PVY exists as a complex of strains producing a range of disease symptoms in various potato cultivars leading to yield reduction, and some of these strains are known to affect tuber quality. In the past 30 years, significant changes in PVY strains circulating in potato crops have been observed in Europe, and more recently in North America, with an increased incidence of PVY strains associated with potato tuber damage. Different models have been proposed to explain these changes, including spread of new recombinants, enhanced vector transmission of certain strains, or introduction of new potato varieties. Here, we analyze the current knowledge of PVY genetic diversity with an emphasis on PVY strains common in North America. Multiple types of PVY genome recombinants with links to specific symptoms in potato varieties are described and discussed. Different approaches to distinguish PVY strains are reviewed and compared, including biological and laboratory methods.