Sequence diversity and interrelationships among isolates of satsuma dwarf-related viruses

The 3'-region of RNA2 of three viruses (Natsudaidai dwarf virus (isolate ND-1), and two unidentified isolates (LB-1, Az-1)), which were related to Satsuma dwarf virus (SDV), were sequenced. Phylogenetic analysis including the previously reported SDV-related viruses (Citrus mosaic virus (CiMV, Ci-968), Navel orange infectious mottling virus (NIMV, NI-1)) showed that they were classified into three groups, SDV (S-58), CiMV (Ci-968, LB-1, Az-1, ND-1), and NIMV (NI-1). The results suggested these groups might correspond to the three distinct virus species. ND-1, LB-1, and Az-1 were considered strains of CiMV, although they do not induce citrus mosaic on the fruit rind.