Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2011
Publication Date: 8/15/2011
Citation: Mello, A., Olarte, R.A., Gray, S.M., Perry, K.L. 2011. Transmission efficiency of Potato virus Y strains PVYO and PVYN-Wi by five aphid species. Plant Disease. Available: https//apsjournals.apsnet.org/DOI: 10.1094/PDIS-11-10-0855. Interpretive Summary: Isolates of Potato virus Y (PVY) are classified into strain groups on the basis of biological characteristics of the virus. In recent years new strains of PVY that cause a more serious disease on potato and other related crops have been emerging in the U.S. We hypothesized that one reason these new, more virulent, strains were becoming more prevalent was because they were transmitted with a higher efficiency by their insect vectors. To this end, we tested the transmission of several isolates of the emerging strain by several known aphid species and compared the transmission to isolates of the common strain of PVY that has been present in the US for many decades. No differences were observed in the transmission efficiency of any of the isolates of either strain by any aphid tested. The data does not support our hypothesis that transmission can account for the emergence of the new strains of PVY.
Technical Abstract: Potato virus Y (PVY) is a re-emerging problem in potato production in North America. While the 'ordinary' strain, PVYO, is still the dominant isolate in U.S. seed potatoes, the recombinant strain of the virus PVYN-Wi (=PVYN:O) has become widespread. An increase in the prevalence of a PVY strain could be due to differences in the efficiency of transmission by aphid vectors. The transmission efficiency by a clone of Myzus persicae was determined for five isolates each of PVYO and PVYN-Wi. An aphid transmission assay was developed based on the use of potato seedlings from true potato seed, allowing for greater control of plant age and growth stage. No apparent differences in transmission by M. persicae were observed. Single isolates of PVYO and PVYN-Wi were tested for their ability to be transmitted from potato to potato by five aphid species: Aphis glycines, A. gossypii, A. nasturtii, M. persicae, and Rhopalosiphum padi. Both PVY isolates showed a similar transmission phenotype in being transmitted efficiently by M. persicae, but very poorly or not at all by A. glycines, A. gossypii, and R. padi. The aphid A. nasturtii transmitted both isolates with an intermediate level of efficiency. The data does not support a model for a differential aphid transmissibility being responsible for the increase in the prevalence of PVYN-Wi.