Species demarcation criteria published in the 8th report are:
Each distinct species usually has a specific natural host range. Distinct species do not cross-protect
in infected common host plant species. Distinct species are readily differentiated by serological
procedures; strains of individual species are often distinguishable in reactions with polyclonal
antisera, but more readily so with monoclonal antibodies. Distinct species have less than ca. 72%
identical nt or 80% identical aa between their CP or polymerase genes.
The virus isolated from peach cross-reacts with antisera to diverse viruses, such as plum pox virus