Full-length genome sequence of the tospovirus melon severe mosaic virus

The complete genome sequence of melon severe mosaic virus (MSMV), genus Tospovirus, family Bunyaviridae, was determined. The small segment is 3283 nucleotide (nt) long and contains two open reading frames in an ambisense organization. The medium segment is 4873 nt long and also encodes two proteins in an ambisense organization. The large segment is 9811 nt long and contains a single, negative-sense ORF. Phylogenetic analysis of each of the five encoded proteins compared to those of tospoviruses present in the databases reveals the same topology for each tree, suggesting that the MSMV genome did not result from recombination or reassortment. Sequence variants present in the RNA population of an infected leaf are described.