Abstract

We report the first identification and complete genome sequence of a watermelon silver mottle virus (WSMoV) isolate, designated WSMoV-MC, infecting bitter gourd ( Momordica charantia L.) from Fujian Province, China. The tripartite genome, comprising large (L, 8,914 nt), medium (M, 4,872 nt), and small (S, 3,555 nt) RNA segments, encodes five typical tospoviral proteins. Sequence analysis revealed that WSMoV-MC shares the highest nucleotide identity (> 99%) with the GL-1 isolate from Siraitia grosvenorii . Phylogenetic analysis based on the nucleocapsid ( N ) gene assigned WSMoV-MC to lineage 2, clustering with other Chinese isolates. Furthermore, a significant reassortment event was detected at the L-M junction, with the GZ isolate (accession no. JX177647) identified as a potential donor. This report expands the known host range of WSMoV and provides essential genomic data for monitoring its molecular evolution in cucurbit crops.