First report of Tobacco vein distorting virus infecting Eupatorium adenophorum in China.
Tobacco vein distorting virus (TVDV), a member of the genus Polerovirus of the family Luteoviridae, is one of the causal agents of tobacco bushy top disease (TBTD) and is mostly transmitted by aphids in a nonpropagative manner. In July 2016, sixteen E. adenophorum (a worldwide noxious invasive weed) samples were collected from three croplands near TBTD-occurring areas in Baoshan, Yunnan Province, southwestern China; among them, 10 of the samples showed slight vein distortion and yellowing on new leaves, whereas the other 6 samples were almost symptomless. To investigate if these symptoms were associated with the causal agents of TBTD or other plant viruses, total nucleic acids were extracted from the 16 E. adenophorum samples using a cetyltrimethylammonium bromide method and analysed by reverse transcription polymerase chain reaction (RT-PCR). Only TVDV was detected from 7 out of 16 samples, and no other virus was detected. All 16 of the E. adenophorum samples were tested by dot-ELISA with antisera against TVDV and confirmed the TVDV infection. Myzus persicae (green peach aphids) feeding on TVDV-infected tobacco plants for 24 h were then transferred onto three groups of 15 healthy E. adenophorum plants (five aphids per plant) for an inoculation access time of 24 h. Two weeks later, the RT-PCR detection results confirmed the presence of TVDV in all of the inoculated E. adenophorum plants. This is thought to be the first report of TVDV infecting E. adenophorum as well as Asteraceae plants.