Molecular identification of a Potexvirus isolate infecting Paris polyphylla var. yunnanensis and analysis of 3′ terminal sequence

One virus isolate, Paris-YN was gained from Paris polyphylla var. yunnanensis in Wuding, Yunnan province. The virus particles were observed as flexuous filaments. The 3′ terminal sequence of the isolate was amplified by RT-PCR, and determined to be 1 074 bp. Comparison and analysis of the nucleotide sequence confirmed that the 3′ terminal sequence of Paris-YN was closely related to that of Potexvirus, and had the sequence identities ranged from 36.7% to 58.9% with 20 viruses of Potexvirus including White clover mosaic virus (WClMV). cp gene of the isolate consisted of 639 nt and encoded 212 aa (22.8 kDa). CP amino acid sequence comparisons with that 20 viruses showed CP of Paris-YN shared the highest amino acid sequence identity (60.1%) with White clover mosaic virus(WClMV). The data suggested Paris-YN was a distinct member of Potexvirus, for which the name Paris polyphylla virus X was proposed.