Possible members of the potyvirus group transmitted by mites or whiteflies share epitopes with aphid-transmitted definitive members of the group.

There are at least ten viruses identified in the literature that resemble definitive potyviruses in having flexuous filamentous particles and inducing the formation of "pinwheel" cytoplasmic inclusions in infected cells but that are transmitted by eriophyid mites, whiteflies or soil fungi and not by aphids, the vectors of the definitive potyviruses. The taxonomic status of these viruses is uncertain at present. Using a broadly cross-reactive antiserum raised against the dissociated coat protein core (residues 68-285) of a definitive potyvirus (Johnsongrass mosaic virus), we have shown that wheat streak mosaic virus which is transmitted by mite and sweet potato mild mottle virus which is transmitted by whitefly have coat proteins that share epitopes with definitive potyviruses. This finding further supports their classification as definitive members of the potyvirus group. The cross-reactive antiserum used here had been shown previously to react with coat proteins of fifteen different definitive potyviruses. The antiserum did not react with coat proteins of potexviruses and tobamoviruses.