MOLECULAR-CLONING AND NUCLEOTIDE SEQUENCING OF THE PARTIAL GENOMES OFAGROPYRON AND HORDEUM MOSAIC-VIRUSES, 2 MEMBERS OF THE RYMOVIRUS GENUS IN THE TAXONOMIC FAMILY POTYVIRIDAE

Complementary DNAs encompassing the coat protein coding and adjacent r egions of Agropyron mosaic virus (AgMV) and Hordeum mosaic virus (HoMV ) were cloned and sequenced, Comparison with other sequenced potyvirus es indicated that each clone contained the 3'-non-coding region (3'NCR ), the coat protein (CP) gene and part of the nuclear inclusion protei n (NIb) gene. Nucleotide and amino acid sequence comparisons of the 3' -terminal regions of these and other rymoviruses indicate that distinc t groups exist. Ryegrass mosaic virus (RGMV)strains share sequence sim ilarity with AgMV and HoMV. Wheat streak mosaic virus (WSMV) and brome streak mosaic virus (BrSMV) form a separate group, sharing limited se quence similarity with the other rymoviruses. It is proposed that subg roups occur within the Rymovirus genus, depending on the vector specie s involved in transmission and on sequences.