Sequence diversity in the coat protein coding region of wheat yellow mosaic bymovirus isolates from China

Isolates of wheat yellow mosaic virus (WYMV) were collected from 11 sites in China and the 3'-terminal portions of RNA1 (including the coat protein coding region) were amplified by reverse transcriptase-polymerase chain reaction and sequenced. No fragment could be amplified from one isolate although WYMV was shown to be present. The sequences of the remaining 10 isolates were compared with other published sequences. The isolates sequenced all had a coat protein coding region of 879 nucleotides and had 96.7-99.9% nucleotides identical to other isolates and between 0 and 11 amino acid differences between them. Unusually for a virus in the family Potyviridae, these differences were mostly in the central region. A consensus amino acid sequence for all bymoviruses was constructed. The 3'-UTR sequences had from 255 to 259 nucleotides with 96.9-100% identical nucleotides between them.