Location: Emerging Pests and Pathogens ResearchTitle: Potato virus Y transmission efficiency from different potato cultivars infected with single or multiple virus strains
|MONDAL, SHAONPIUS - CORNELL UNIVERSITY - NEW YORK|
|LIN, YU-HSUAN - TAIWAN AGRICULTURAL RESEARCH INSTITUTE|
|CARROLL, JULIET - CORNELL UNIVERSITY - NEW YORK|
|WENNINGER, ERIK - UNIVERSITY OF IDAHO|
|PEREZ, NILSA BOSQUE - UNIVERSITY OF IDAHO|
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2016
Publication Date: 4/1/2017
Citation: Mondal, S., Lin, Y., Carroll, J.E., Wenninger, E.J., Perez, N., Whitworth, J.L., Gray, S.M. 2017. Potato virus Y transmission efficiency from different potato cultivars infected with single or multiple virus strains. Phytopathology. 107:491-498.
Interpretive Summary: Emerging strains of Potato virus Y are more damaging to the U.S. potato industry because they can cause a tuber necrotic disease which reduces the quality of the potato and renders it unmarketable. The rapid emergence and expansive distribution of the new strains is unprecedented and the factors driving the changes are unknown. This research investigated whether the new strains of the virus are more efficiently transmitted by aphids when acquired from plants infected with one or more strains of PVY. Transmission of the new strains tended to be slightly more efficient if they were acquired from plants only infected by one strain. However, if aphids acquired virus from plants infected with two or more strains, which is not uncommon in potato fields, the old strain tended to be transmitted more efficiently although the differences were not always significant and transmission efficiency was influenced by potato cultivar and the isolate of the virus being used. All in all, the data do not support the hypothesis that differential transmission of the new strains is a major factor driving their emergence.
Technical Abstract: There has been a shift in the prevalence of Potato virus Y (PVY) strains affecting the U.S. potato crop in recent years. The incidence of the ordinary strain, PVYO, is now significantly less than the emerging recombinant strains, e.g. PVYNTN, PVYN:O/NWi. It is not uncommon to find several PVY strains in potato fields and even in individual plants. The factors contributing to the emergence of the recombinant strains are many and not well defined, but differential transmission of strains by aphids from single and mixed infections has been hypothesized to play a role. Here we examine the transmission efficiencies of PVY isolates representing the predominant strains between potato plants of different cultivars. The transmission efficiency of PVYO, PVYN:O and PVYNTN varied depending on the potato cultivar serving as the virus source. In general, PVYNTN was transmitted at higher efficiency than PVYO and PVYN:O, but differences were not always significant. Overall transmission efficiency from double strain infections was variable and not significantly increased over single strain infections, although the overall transmission from the triple strain infection was significantly higher than from single or double strain infections. Two strains were concomitantly transmitted by individual aphids from mixed infections for many of the combinations, especially if PVYO was present. Three strains were not transmitted by any single aphid. Interestingly, PVYO was transmitted most efficiently from mixed strain infections. Similar to other published studies on transmission efficiency of PVY strains, no sweeping conclusions are possible about preferential transmission of any one PVY strain, but rather the associations are complex and influenced by virus isolate, genotype of source plant, and likely time of infection, aphid clonal lineage and order of strain/isolate acquisition. Overall, the data do not support the hypothesis that differential transmission of PVY strains is a major contributing factor in the emergence of recombinant PVY strains in the U.S. potato crop.