The Occurrence of PVY^O, PVY^N, and PVY^N:O Strains of Potato virus Y in Certified Potato Seed Lot Trials in Washington and Oregon

Abstract

Totals of 960 and 286 certified potato seed lots from locations across North America were planted in trials in Washington and Oregon, respectively, in 2001 to 2003 and tested for strains of Potato virus Y (PVY). The incidence of PVYO-infected lots averaged 16.4 and 25.9% in the Washington and Oregon trials, respectively. There was a general trend of increasing incidence of the PVYO, PVYN:O, and PVYN strains during this period, as evidenced by more infected cultivars, sites of seed origin, and number of seed growers providing infected seed lots. In particular, there was a dramatic increase in seed lots with the PVYN:O strain from 2002 to 2003. PVYN:O, in contrast to PVYO, which only causes yield reduction, also causes internal and external damage to tubers, making them unmarketable. In 2003, PVYN:O occurred in seed lots originating in eight states and three Canadian provinces. The increased incidence of PVYN:O was likely due to the difficulty in differentiating this strain from PVYO. The prevalence of PVY in potato seed lots documented herein poses a threat to potato production in the United States and suggests that current measures to reduce the incidence of this virus are inadequate.

Potato virus Y: An Evolving Concern for Potato Crops in the United States and Canada

“…(16,59,60,69, and this study) and is problematic because it is not always detected in serological tests used by certification and regulatory agencies as a tobacco necrotic strain. The PVY O -O5 variant accounted for 6 and 3% of the total isolates from the United States and Canada, respectively.…”

Potato virus Y (PVY) strains in Belgian seed potatoes and first molecular detection of the N-Wi strain

“…Available data indicate that the N strain group (including PVY N , PVY NTN and PVY N-Wi strains) is the most common strain group in Europe (Weidemann 1988, Glais et al 1998, Glais et al 2002, Nie & Singh 2003b, while in North America, the ordinary strain group (PVY O ) still has a predominant place (Crosslin et al 2006, Lorenzen et al 2006a, Nanayakkara et al 2012. Both in Germany (Lindner 2008) and Switzerland (Rigotti et al 2011), the NTN-strain has been shown to be the most prevalent PVY strain, although both authors report a gradual shift over the years toward prevalence of the PVY N-Wi strain.…”

Recombinants of PVY Strains Predominate Among Isolates from Potato Crop in Poland

“…Wilga collected from west Poland in 1984 (Chrzanowska 1991) and the first PVY NTN isolate (named 12/94) was detected on a tobacco bait plant grown in a potato field at Młochów in 1994 (Chrzanowska and Doroszewska 1997). Both PVY N-Wi and PVY NTN are recombinants between the PVY O and PVY N strains (Glais et al 2002;Crosslin et al 2006;Schubert et al 2007;Visser and Bellstedt 2009;BoukhrisBouhachem et al 2010). Recently, a novel PVY strain variant NE-11 has been shown to be a recombinant between PVY N and North American type PVY NTN (Lorenzen et al 2008) and the variant PVY NTN-NW a recombinant between PVY NTN and PVY N-Wi (Chikh Ali et al 2010).…”