Pfaffia mosaic virus: a new potyvirus found infecting Pfaffia glomerata in Brazil

In Brazil plants of Pfaffia glomerata with mosaic symptoms were found to be infected with a previously undescribed potyvirus, Pfaffia mosaic virus (PfMV). Virus particles were long and flexuous, c. 10 × 700–800 nm, and cylindrical inclusions typical of potyviruses were present in cells of infected tissue. Partial host‐range studies revealed that in addition to P. glomerata , PfMV infected only Chenopodium amaranticolor and Chenopodium quinoa . It was efficiently transmitted by the aphids Aphis gossypii and Myzus persicae . Polyclonal antiserum produced against the PfMV coat protein (CP) reacted with Potato virus Y (PVY), but not with four other potyviruses in PTA‐ELISA. The similarity of the nucleotide sequence of the PfMV coat‐protein gene ( CP ) varied from 7 to 76% when compared with other members of the family Potyviridae . Similarity of the 3′ NTR sequence varied from 4 to 23%. In both cases the highest similarity was with PVY. These data indicate that PfMV is a new species in the genus Potyvirus .