Biological and sequence data suggest that potato rough dwarf virus (PRDV) and potato virus P (PVP) are strains of the same species

Potato rough dwarf virus (PRDV, genus Carlavirus) was originally described in Argentina by Butzonitch et al. [1]. Potato virus P (PVP) had been reported previously in Brazil [3] and also catalogued as a member of the genus Carlavirus [5]. PRDV presents frequent asymptomatic infections, and when symptoms appear, causes dwarfism, leaf deformation, leaf roughness, and systemic interveinal chlorosis [5]. Until now, PVP has been reported to be asymptomatic [5]. Nicotiana occidentalis has been used as propagation host and inoculated mechanically at the 3–4 leaf stage with sap from infected leaves from original virus sources (cv. Sierra Volcan INTA for PRDV and from cv. Baronessa for PVP). Previous results using double antibody sandwich enzyme-linked immuno-sorbent assay (DAS-ELISA) [2] showed cross-reactions in PVP-infected plants with anti-PRDV and vice versa [1].