ARS | Publication request: SEROLOGICAL AND MOLECULAR DETECTION OF TOBACCO VEINAL NECROSIS ISOLATES OF POTATO VIRUS Y (PVY N) FROM POTATOES GROWN IN THE WESTERN UNITED STATES

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 7, 2004
Publication Date: September 1, 2005
Citation: Crosslin, J., Hamm, P.B., Shiel, P.J., Hane, D.C., Brown, C.R., Berger, P.H. 2005. Serological and molecular detection of tobacco veinal necrosis isolates of potato virus Y (PVYN) from potatoes grown in the western United States. American Journal of Potato Research 82:263-269.

Interpretive Summary: Potato virus Y (PVY) is found worldwide wherever potatoes are grown. The virus is transmitted from plant to plant by several species of aphids. Different types, or strains, of the virus have been described. The 'ordinary' strain (PVYO) causes mild symptoms in potato leaves and does not cause necrosis (death) of leaves of tobacco plants. Another strain, PVYN, causes necrosis on tobacco and produces very mild, or no, symptoms in most varieties of potato. A third strain, PVYNTN, is a subgroup of PVYN which causes internal symptoms in tubers of some potato varieties. Many of the PVYO and PVYN strains can be detected and differentiated by serological tests using monoclonal antibodies specific for each strain. Recently, however, PVYN strains were reported in the US which could not be differentiated from the PVYO strain using the available antibodies. These viruses have been found to be 'recombinants' which possess properties of both PVYO and PVYN strains, and have been designated PVYN:O. To detect these viruses a molecular test called RT-PCR is needed. We have tested several isolates of PVY found in potatoes in the western US using the available antibodies and a simplified RT-PCR procedure and found that the recombinant viruses can be reliably detected and differentiated from the ordinary strain of PVY.

Technical Abstract: Isolates of Potato virus Y potyvirus which induced systemic veinal necrosis in tobacco (PVYN) were transmitted from potatoes grown in Washington, Oregon, California, and Idaho. The detection of these viruses by serological and molecular methods was evaluated. In addition to PVYN-like isolates, putative recombinant isolates (PVYN:O) were detected. ELISA tests using monoclonal antibodies specific for ordinary (PVYO) or necrosis-inducing (PVYN) serotypes of the virus indicated that both O and N serotypes were represented among the PVYN isolates. A novel coupled, one-tube, duplex reverse transcription-polymerase chain reaction (cRT-PCR) assay was developed which allowed all of the necrosis-inducing PVYN and PVYN:O isolates to be rapidly detected and differentiated from the ordinary strain.