Cloning and sequencing of RNA-1 cDNA from cucumber mosaic virus strain O.

The complete nucleotide (nt) sequence (3369 nt) of RNA 1 of cucumber mosaic virus strain O (CMV-O) was determined. One open reading frame (ORF; 993 aa) could be deduced from the nt sequence. The homologies of the ORF between CMV-O and CMV-Q or CMV-Fny were calculated to be 85% or 97%, respectively. For CMV-O and CMV-Q, the first one-third of the ORF showed a higher degree of homology (89%), as compared with the other portions (82-85%); the first 224 aa showed more than 93% homology. A comparative study of the three viruses revealed that CMV-O is more homologous to CMV-Fny (subgroup I) [corrected]) than to CMV-Q (subgroup II) [corrected].