The present work describes the identification and characterization of a potyvirus isolated from Zinnia elegans in the northwest region of the State of São Paulo, Brazil. The Zinnia potyvirus was transmitted by mechanical inoculation. Its host range was restricted mainly to members of the Asteraceae family. By SDS-PAGE, the molecular mass of the coat protein (CP) was estimated to be 33 kDa and, in Western-blot, it reacted with antiserum to Bidens mosaic virus (BiMV). A fragment of about 820 bp was amplified by RT/PCR, cloned and sequenced. The fragment, which included the CP gene, displayed amino acids similarity in the CP core ranging from 55% (Tobacco vein mottling virus, TVMV) to 95% (Sunflower chlorotic mottle virus, SuCMoV). For the whole CP, it ranged from 55% (TVMV) to 91% (SuCMoV). In the N-terminal region the Zinnia potyvirus has a deletion of four amino acids (positions 9 to 12 downstream of the cleavage site between the protein NIb and the CP) when compared with the SuCMoV sequence. Filogenetic analysis grouped the Zinnia potyvirus and SuCMoV in the same branch in 100% of the replicates, showing a very close relationship between these two viruses. The results obtained in the present work demonstrate that the Zinnia potyvirus and SuCMoV are strains of the same virus. The name Sunflower chlorotic mottle virus, Zinnia isolate (SuCMoV-Zi), is suggested for the potyvirus found in Z. elegans in Brazil.
