Aphid Transmission of Potato aucuba mosaic virus Strains Mediated by Different Strains of Potato virus Y

Three British strains of potato aucuba mosaic virus "PAMV# were tested for transmissibility by the aphid Myzus persicae[ None was aphid transmissible on its own but all three were transmitted in the nonpersistent manner by aphids that had previously been fed on a source of the potyvirus potato virus Y "PVY#[ Di}erent PVY strains mediated PAMV transmission from Nicotiana clevelandii to Capsicum annuum to di}erent degrees\ and di}erent PAMV strains were transmitted at di}erent frequencies when assisted by the same PVY strain[ These results are compatible with the idea that subtle di}erences in the PAMV coat protein and in the PVY helper component are responsible for di}erences in frequencies of trans! mission of PAMV\ without however\ excluding the possi! bility of e}ects of other unde_ned factors[ Transmission of PAMV was no less frequent when mediated by a PVY strain that was unable to infect C[ annuum than when a C[ annuum!infecting PVY strain was used[