IDENTIFICATION AND GEOGRAPHIC-DISTRIBUTION OF SEROTYPES OF POTATO-VIRUS-Y

From a panel of 10 monoclonal antibodies (MAbs) prepared against speci fic isolates representing the three recognized strain groups of potato virus Y (PVY), i.e., common (PVYO), tobacco veinal necrosis (PVYN), a nd stipple streak (PVYC), seven were selected for serotype analysis. T hese MAbs were tested for reactivity with 52 PVY strains representing all three strain groups from an international collection. Within the P VYN strain group, five serotypes were identified and designated N-1 to N-5 The PVYO strain group was more diverse, and nine serotypes were d efined and designated O-1 to O-9. Only one serotype, designated C-1, w as defined within the PVYC strain group. The same panel of MAbs was us ed to test 632 PW samples collected from potato seed certification plo ts in North America. Although no PVYN serotypes were found, all of the PVYO serotypes were identified, and several samples, tentatively assi gned to the C-1 serotype, were found.