Serological Analysis and Coat Protein Sequence Determination of Potato Virus Y (PVY) Pepper Pathotypes and Differentiation from Other PVY Strains

The serological relationships of Potato Virus Y (PVY) isolates belonging to the pepper pathotypes 0, 1 and 1-2 were established by enzyme-linked immunosorbent assay (ELISA). PVY pepper pathotypes did not react with monoclonal antibodies which typically recognize non-pepper strains within the PVY group, leading to discrimination between these two groups of strains. No serological differences were found between the three PVY pepper pathotypes. The coat protein (CP) nucleotide and predicted amino acid sequences of the three different PVY pepper pathotypes were determined. The highest sequence similarity was found between pathotypes 0 and 1 (99.2%), while the lowest occurred between these two and pathotype 1–2 (98.1%). PVY strains from potato and tobacco appeared more distantly related. Phenetic analysis of the CP amino acid sequences showed that the PVY pepper pathotypes formed a tightly clustered group separate from other PVY strains.