Submitted to: Archives of Virology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/9/1995
Publication Date: N/A
Citation: Interpretive Summary: Barley yellow dwarf virus (BYDV) is one of the most important viruses of cereals in the USA and the rest of the world. There are at least 5 strains of BYDV which are transmitted by different aphid species. BYDV-RMV from New York is transmitted by the corn leaf aphid but a Montana RMV isolate is also transmitted by the greenbug. Because the virus coat protein may be responsible for vector specificity, we determined the coat protein gene sequences of both isolates. The two isolates were only 80% similar. The RMV isolates were almost as different from each other as BYDV strain PAV differs from strain MAV. This suggests that coat protein mediated resistance for BYDV may not be a useful approach for control of the RMV strain of BYDV. Variability among RMV isolates may also pose problems for disease diagnosis using antibodies. A polymerase chain reaction method developed by us for identifying BYDV was able to detect both New York and Montana RMV isolates and may be a more reliable diagnostic procedure.
Technical Abstract: A Montana barley yellow dwarf virus (BYDV) isolate, BYDV-RMV-MT, is serologically identical to the New York RMV type isolate (RMV-NY) but differs in aphid vector specificity. A purification procedure for BYDV-RMV-MT was developed and cDNAs encompassing the entire coat protein gene and a portion of the putative polymerase gene of both RMV-MT and RMV-NY were cloned and sequenced. Diameters of RMV-MT virions averaged 24.7 nm. Average virus yield was 4.2 mg/Kg plant tissue. There was 81% sequence identity between the clones of MT and NY RMV isolates at the nucleotide level. At the amino acid level the polymerase genes were 91% identical to each other and 74% homologous with that of beet western yellows virus. The coat protein amino acid sequences of the two RMV isolates were only 81% identical and, compared to other sequenced luteoviruses, both were most similar to cucurbit aphid-borne yellows virus.