Identification and characterization of a novel tospovirus species using a new RT-PCR approach.

A novel tospovirus serologically distinct from all established tospovirus species was found in Thailand in Physalis minima L. The S RNA of this virus was cloned by a new RT-PCR approach revealing a nucleotide sequence of 3257 nucleotides. The ambisense RNA segment encoded a nonstructural protein (NSs) of 469 amino acids, with a predicted Mr of 53.2 kDa, and a nucleoprotein (N) of 279 amino acids and a Mr of 31.0 kDa, so far the largest N protein known for any tospovirus species. N protein sequence comparisons revealed closet relationship to the species Watermelon bud necrosis virus (58% identity), Watermelon silver mottle virus and Peanut bud necrosis virus (57%) and a distant relationship to Peanut yellow spot virus (23%) and Peanut chlorotic fanspot virus (22%).