Abstract
Coat proteins of 7 biologically defined isolates of cucumber mosaic virus were compared by peptide mapping and enzyme-linked immunosorbent assay (ELISA). All 7 isolates could be classified in either of 2 subgroups, confirming previous reports of the existence of these groups. Isolates B, C-1, C-2, and F were placed in 1 subgroup, while isolates L-2, L-3, and WL were placed in the other. Isolates within a subgroup were indistinguishable. One-dimensional peptide mapping apparently is a reliable and sensitive technique that can complement existing viral classification techniques.