Complete genome sequence of a putative new idaeovirus identified in Cynanchum rostellatum in China

A new bipartite idaeovirus tentatively named "Cynanchum rostellatum idaeovirus 1" (CRIV-1) was identified inCynanchum rostellatum exhibiting yellow spots and yellow mosaic symptoms in China. CRIV-1 RNA-1 is 5,418 nucleotides (nt) in length and encodes a polyprotein containing methyltransferase (MTR), helicase (Hel), and RNA-dependent RNA polymerase (RdRp) domains. RNA-2 is 2,224 nt in length and encodes a putative movement protein (MP) and a coat protein (CP). CRIV-1 was found to share the highest nt/amino acid (aa) sequence identity with raspberry bushy dwarf virus (AB948214) in the polyprotein (61.2%/61.8%), with black mulberry idaeovirus (MW017549) in the CP (57.3%/47.4%), and with Actinidia yellowing virus 3 (OL581736) in the MP (59.4%/57.6%). Phylogenetic analysis based on polyprotein aa sequences showed a close relationship of CRIV-1 to other idaeoviruses. CRIV-1 can be transmitted to C. rostellatum andNicotiana benthamiana plants via mechanical inoculation. Collectively, our data support the classification of CRIV-1 as a new member of the genus Idaeovirus.