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 i n China and the 3'-terminal portions of RNA1 (including the coat protein co ding region) were amplified by reverse transcriptase-polymerase chain react ion and sequenced. No fragment could be amplified from one isolate although WYMV was shown to be present. The sequences of the remaining 10 isolates w ere compared with other published sequences. The isolates sequenced all had a coat protein coding region of 879 nucleotides and had 96.7-99.9% nucleot ides identical to other isolates and between 0 and 11 amino acid difference s between them. Unusually for a virus in the family Potyviridae, these diff erences were mostly in the central region. A consensus amino acid sequence for all bymoviruses was constructed. The 3'-UTR sequences had from 255 to 2 59 nucleotides with 96.9-100% identical nucleotides between them.