Characterization of a Strain of Tobacco Mosaic Virus from Petunia

Petunia plants collected in SaÄo Paulo City, Brazil, showing yellow mosaic, were naturally infected by a virus of the genus Tobamovirus identi®ed according to particle morphology and size, host range, physical properties and cytopathic e€ects. On the basis of sero- logical properties, amino acid composition and nucleo- tide sequence of the coat protein gene, the virus isolate was identi®ed as a new strain of Tobacco mosaic virus (TMV-p). A conspicuous feature of this virus infection is the presence of virus-like particles within the mito- chondrial matrix. The data from phylogenetic analysis indicate that TMV-p belongs to subgroup 1 of the genus Tobamovirus