Biological, Cytopathological and Molecular Characterisation of Pepper Ringspot Virus From Solanum violifolium in Brazil

ABSTRACT In 2022, Solanum violifolium plants showing yellow rings and line pattern symptoms were observed in the municipality of Piracicaba, São Paulo State, Brazil. Plate‐trapped antigen‐ELISA and reverse transcription‐PCR followed by Sanger sequencing confirmed the occurrence of pepper ringspot virus (PepRVS, Tobravirus capsici ) in all field‐collected plants. The isolate of PepRVS (PepRSV_BR) obtained from S. violifolium in this study was mechanically transmitted to S. violifolium , Chenopodium amaranticolor , Chenopodium quinoa , Gomphrena globosa , Nicotiana tabacum , but not bell pepper ( Capsicum annuum ), tomato ( Solanum lycopersicum ), eggplant ( Solanum melongena ) and scarlet eggplant ( Solanum aethiopicum ) plants. Transmission electron microscopy analysis of leaf extracts and ultrathin sections of S. violifolium , C. amaranticolor , C. quinoa , G. globosa , N. tabacum cvs. TNN, Turkish and Samsun revealed a consistent presence of rod‐shaped particles approximately 200 and 50 nm long, with a diameter of approximately 25 nm. High‐throughput sequencing analysis of one field‐sample yielded two contig sequences of 6813 and 2446 nucleotides corresponding to PepRSV RNA 1 and 2, respectively. Genome analysis also revealed that RNA 2 of PepRSV_BR contains a truncated open reading frame (ORF) 2c and a putative ORF 2d. Future studies involving the production of an infectious clone may help to understand the roles of the truncated ORF 2c and the putative ORF 2d in aspects of plant–vector–virus interaction.