Conyza canadensis, a new host of Tobacco leaf curl Yunnan virus in China

In April 2023, leaf curl, crinkling symptoms were found on Conyza canadensis plants around tobacco fields located at Yuxi, Yunan province, China. PCR detection with genus-specific primers showed that symptomatic C. canadensis plants was infected by begomovirus. The full-length viral components and satellite molecules from the diseased C. canadensis (YN-2023) were obtained by enrichment of circular DNA with rolling circle amplification, restriction enzyme digestion, cloning, and DNA sequencing. The viral component (2, 750 nt, OR509733) shared the highest nt identity at 92.4% to tobacco leaf curl Yunnan virus isolate YN5741 (TbLCYNV-YN5741 [CN:Yn:Age:16], MN218671). A satellite molecule (1, 339 nt, OR509734) shared the highest nt identity at 86.5% to tobacco curly shoot betasatellite isolate Y115 (TbCSB-Y115 [CN:Yn:03], AJ457822). Another satellite molecule (1, 357 nt, OR509735) shared the highest nt identity at 94.2% to ageratum yellow vein Singapore alphasatellite (AYVSGA-[Singapore:1998], NC003414). Based on the threshold for classification of Begomovirus, Betasatellite, Alphasatellite, YN-2023 was a new strain of TbLCYNV and associated with TbCSB and AYVSGA. To our best knowledge, this is the first report that C. canadensis is a natural host of TbLCYNV.