Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/29/2006
Publication Date: 5/1/2006
Citation: Baldauf, P., Gray, S.M., Perry, K. 2006. Biological and serological properties of potato virus y isolates in northeastern us potatoes. Plant Disease. 90:559-596. Interpretive Summary: There are 36 viruses in several different genera that are known to infect potatoes in agricultural settings although their prevalence has been greatly reduced through effective seed certification programs. Recently, Potato virus Y (PVY) has re-emerged as a serious seed potato production problem. The ordinary strain of PVY (PVY0) causes observable mosaic symptoms, lower leaf drop, and stunting in most potato cultivars. PVY0 incidence has been minimized by seed certification programs and has not been considered to be a major impediment to potato production although widespread acceptance of cultivars that are asymptomatic to PVY0 infection has contributed in increased PVY incidence in recent years. The necrotic strains of PVY cause a lethal veinal necrosis in tobacco and some are able to induce necrotic ringspot symptoms in potato tubers which greatly reduces marketability. This study describes a potato virus survey conducted in the Northeastern United States in 2002 and 2003 and the biology of several PVY isolates that differ from the common PVY0 strain and that are related to the necrotic strains. Consistent with reports from other US potato growing regions, we identified necrotic isolates and antigenic variants of PVY in the Northeastern US. Although the frequency at which these isolates were recovered was low, it is clear that necrotic PVY and other variants are widespread and becoming more prevalent. This is the first report of necrotic or tuber necrotic strains of PVY and of potential PVY genetic recombinants in potatoes grown in the Northeastern US.
Technical Abstract: A survey of six potato viruses; PVA, PVM, PVS, PVX, PVY, and PLRV was conducted in New York and Maine during 2002 and 2003. Leaf samples were tested by ELISA and PVY-positive samples were further tested to determine if PVYN or PVYNTN were present. In both years, PVY and PVS were identified in a majority of the samples and mixed infections predominated in 83% of the symptomatic leaves in 2002. Three of the total 386 PVY-positive samples reacted with monoclonal antibody (MAb) 1F5 and caused veinal necrosis (VN) in tobacco. Two of these isolates caused tuber necrosis in the potato cultivar Yukon Gold. Three PVY isolates reacted with MAb 1F5 but did not cause VN in tobacco, and two caused VN, but did not react with MAb 1F5. None of these eight isolates were able to overcome the Ry resistance gene in the potato cultivar Eva, but several were able to overcome the Ny resistance gene found in Allegany. PVYN isolates are not widespread in the Northeast; however, several PVY isolates differ from both PVYN and PVY0 and may represent strain recombinants.