Tombusvirus-like associated RNAs (tlaRNAs) are positive-sense single-stranded RNAs found in plants co-infected with some viruses of the genus Polerovirus. Pod pepper vein yellows virus (PoPeVYV) was recently reported as a new recombinant polerovirus causing interveinal yellowing, stunting, and leaf rolling in Capsicum frutescens plants at Wenshan city, Yunnan province, China. The complete genome sequence of its associated RNA has now been determined by next-generation sequencing and reverse transcription (RT) polymerase chain reaction (PCR). PoPeVYV-associated RNA (PoPeVYVaRNA) (GenBank Accession No. MW323470) has 2970 nucleotides and is closely related to other group II tlaRNAs, particularly tobacco bushy top disease-associated RNA (TBTDaRNA, GenBank Accession No. EF529625). In infection experiments on Nicotiana benthamiana and C. frutescens plants, synergism between PoPeVYVaRNA and PoPeVYV was demonstrated, leading to severe interveinal yellowing of leaves and stunting of plants. The results provide further information on the genetic and biological properties of the various agents associated with pepper vein yellows disease (PeVYD).

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An isolate of chilli veinal mottle virus (ChiVMV; genus Potyvirus) of Solanum nigrum L. from southwest China (ChiVMV-YunN/Yuxi) was identified and sequenced (GenBank: OP404087). Comparison with other ChiVMV isolates and recombination analyses suggested a recombinant origin. The most significant recombination event among all 21 complete ChiVMV isolates was an ending breakpoint at 1408–1488 for ChiVMV-YunN/Yuxi with ChiVMV-TaiW and ChiVMV-YunN/Ca operating as the respective major and minor parents. Interestingly, the 5′ UTR of ChiVMV-YunN/Yuxi is 15 nucleotides (‘AAAAATAAAACAACC’) longer than other reported isolates. A full-length clone of ChiVMV-YunN/Yuxi was constructed and was shown to be infectious in Nicotiana benthamiana. The additional 15 nt of 5′ UTR in ChiVMV-YunN/Yuxi was stable when transmitted through three generations. Experiments with modified clones showed that the additional 15 nt are essential for infection by this isolate.