Melon yellow spot virus: A distinct species of the genus Tospovirus isolated from melon

A tospovirus-like virus recovered from netted melon was transmitted by Thri ps palmi in a persistent manner but had different cytopathological features from tospoviruses previously reported. Viral nucleocapsid (N) was purified with two protective reagents, 2-mercaptoethanol and L-ascorbic acid, and R NA extracted from the viral nucleocapsid was used for genomic analysis. The virus had a genome consisting of three single-stranded RNA molecules. The open reading frame on the viral complementary strand, located at the 3' end of the viral S RNA, encoded the N protein. The 3' terminus of this RNA als o contained an eight-nucleotide sequence similar to the conserved sequence at the 3' end of genomic RP FA molecules of tospoviruses. These features of the viral genome are identical to those of tospoviruses; therefore, this v irus is considered to belong to the genus Tospovirus. its N protein compris ed 279 amino acids and had a molecular mass of 31.0 kDa. Comparisons of its amino acid sequence: with those of known tospoviruses revealed less than 6 0% identity. This melon virus is concluded to be a distinct species in the genus Tospovirus, and the name Melon yellow spot virus is proposed.