COMPLETE RNA1 SEQUENCES OF 2 UK ISOLATES OF BARLEY MILD MOSAIC-VIRUS - A WILD-TYPE FUNGUS-TRANSMISSIBLE ISOLATE AND A NON-FUNGUS-TRANSMISSIBLE DERIVATIVE

The complete RNA1 sequences of two isolates (fungus transmissible and non-fungus transmissible) of barley mild mosaic virus (BaMMV) were obt ained. The two isolates' RNA1 sequences had very high sequence identit y (99.3%), and of the 15 amino acid differences (out of 2258) between the putative polyproteins, 11 were conservative and unlikely to affect the structure or function of the protein. The remaining amino acid di fferences were thought unlikely to affect fungus transmission because they occur in the CI- and NIb-coding regions. This strongly suggests t hat the P73 protein of RNA2 (which has a 364-aa deletion in the non-fu ngus-transmissible isolate) is involved in fungus transmission of BaMM V. (C) 1997 Elsevier Science B.V.