Complete genome sequences of three tomato spotted wilt virus isolates from tomato and pepper plants in Korea and their phylogenetic relationship to other TSWV isolates.

Tomato spotted wilt virus (TSWV) infects numerous host plants and has three genome segments, called L, M and S. Here, we report the complete genome sequences of three Korean TSWV isolates (TSWV-1 to -3) infecting tomato and pepper plants. Although the nucleotide sequence of TSWV-1 genome isolated from tomato is very different from those of TSWV-2 and TSWV-3 isolated from pepper, the deduced amino acid sequences of the five TSWV genes are highly conserved among all three TSWV isolates. In phylogenetic analysis, deduced RdRp protein sequences of TSWV-2 and TSWV-3 were clustered together with two previously reported isolates from Japan and Korea, while TSWV-1 grouped together with a Hawaiian isolate. A phylogenetic tree based on N protein sequences, however, revealed four distinct groups of TSWV isolates, and all three Korean isolates belonged to group II, together with many other isolates, mostly from Europe and Asia. Interestingly, most American isolates grouped together as group I. Together, these results suggested that these newly identified TSWV isolates might have originated from an Asian ancestor and undergone divergence upon infecting different host plants.