First report of turnip mosaic virus infecting Perilla frutescens in Korea.
During a survey in May 2016, virus-like symptoms were observed on 70-80% of Perilla frutescens plants on a farm located in Chuncheon, Korea Republic. Symptoms included mild mosaic and yellowing symptoms. To identify the causative virus, total RNA was extracted from the leaves of affected P. frutescens and seven genus-specific primer sets for Ilarvirus, Potyvirus, Fabavirus, Tospovirus, Potexvirus, Tobamovirus and Cucumovirus detection were used for RT-PCR. Nicotiana benthamiana and N. tabacum were mechanically inoculated from affected P. frutescens and observed for symptoms. Necrotic local lesions were induced on the inoculated leaves of N. tabacum, suggesting Turnip mosaic virus (TuMV) infection. To confirm the presence of TuMV and determine the full-length sequence of this isolate, six pairs of primers targeting conserved regions of the TuMV genome were designed. Using these primers, the complete sequence of an isolate of TuMV named TuMV-KPF (GenBank accession No. LC413507) were determined. This is thought to be the first report of TuMV infection in P. frutescens in Korea Republic or elsewhere.