Identification and Geographic Distribution of Serotypes of Potato Virus Y.

From a panel of 10 monoclonal antibodies (MAbs) prepared against specific isolates representing the three recognized strain groups of potato virus Y (PVY), i.e., common (PVYO), tobacco veinal necrosis (PVYN), and stipple streak (PVYC), seven were selected for serotype analysis. These MAbs were tested for reactivity with 52 PVY strains representing all three strain groups from an international collection. Within the PVYN strain group, five serotypes were identified and designated N1 to N5. The PVYO strain group was more diverse, and nine serotypes were defined and designated O1 to O9. Only one serotype, designated C1, was defined) within the PVYC strain group. The same panel of MAbs was used to test 632 PVY samples collected from potato seed certification plots in North America. Although no PVY(N) serotypes were found, all of the PVYO serotypes were identified, and several samples, tentatively assigned to the C1 serotype, were found.