| In this study,transcriptome sequencing,RT-PCR amplification and transmission electron microscopy(TEM)were used to analyze the yellow mottled leaf samples of Euonymus bungeanus and the shrinking leaf samples of Chenopodium album L were collected in Shenyang,Liaoning Province.The results are as follows: The virus associated with the diseased E.bungeanus is a new virus belongs to Potexvirus,Alphaflexiviridae.The virus associated with the diseased C.album L is an isolate of Broad bean wilt virus 2(BBWV2)in the genus Fobavirus of the family Comoviridae.This study not only discovered a new virus in woody plants expanding the plant virus resource,but also further enriched the natural host range of BBWV2,providing the foundation for the prevention and control of plant virus diseases.In July 2018,the suspected diseased leaves of the Euonymus bungeanus were collected in Shenyang of Liaoning Province.Flexuous filaments(500 x 13 nm)were observed using Transmission Electron Microscope(TEM).A potexvirus was amplified and obtained in a subsequent experiment using transcriptome sequencing technology and RT-PCR technique.The complete viral genome is 6,784 nucleotides in length(excluding the poly(A)tail),contains five open reading frames,and shares.the highest homology with Euonymus yellow vein associated virus(EuYVAV,MF078061)(41.0%).Based on the nucleotide and amino acid sequences of the Coat protein(CP)gene,the virus has the highest sequence similarity to Cymbidum mosaic virus(CyMV,EF125179)with 43.9% and 38.8%,respectively.Phylogenetic analysis indicated that the virus had the highest homology with EuYVAV and belonged to the same branch of potexviruses.Based on the comprehensive analysis of the above experimental results,the virus is considered to be a new virus belonging to the Potexvirus and is named it as Euonymus yellow mottle associated virus(EuYMaV).This is another case of the potexvirus infecting Euonymus bungeanus.In June 2016,leaf samples of C.album L showing signs of shrinkage were collected in Shenyang,Liaoning Province.A virus of the genus Fabavirus(Comovirinae)was amplified from the diseased leaves using transcriptome sequencing technology and RT-PCR technology.The viral genome contains two single-stranded RNA molecules.The full-length genome of RNA1 was 5,891 nucleotides,and the full-length genome of RNA2 was 3,549 nucleotides.In order to clarify the classification of the virus,the homology and phylogenetic analysis were analyzed between it and other reported BBWV2.Based on the amino acid sequence analysis of the virus CP gene,the virus was found to have the highest homology with Korean isolate BBWV2-[SK:Leonurus sibiricus](KM076649),which was 96.5%.According to Fabavirus classification criteria,the virus should be an isolate of BBWV2 in Liaoning.This is the first report of BBWV2 infection by Chenopodiaceae plants in the world. |
