Detection And Identification Of Three Woody Plant Virus Diseases In Shenyang

In this study,the viruses were identified in three woody plant samples from Liaoning by transmission electron microscopy,small RNA deep sequencing and RT-PCR amplification.The virus invading the Euonymus bungeanus Maxim.was identified as a new virus in the genus Potexvirus of the family Alphaflexiviridae;The virus infecting Phellodendron amurense Rupr.was identified as a new virus in the newly established genus Roymovirus in the family Potyviridae.A new virus of the genus Roymovirus;The virus infesting Syringa reticulata var.mandshurica is a Liaoning isolate of the genus Ligustrum virus A?LVA?in the genus Carlavirus of family Betaflexiviridae.This study enriched the virus resources of woody plants and laid a theoretical foundation for the prevention and control of woody plant diseases.?1?In August 2016,the leaves of Euonymus japonicus with symptoms of yellow vein were collected in Shenyang,Liaoning Province,and 750×13 nm virions were observed by transmission electron microscopy.A Potexvirus is amplified in the sample by small RNA deep sequencing and RT-PCR molecular cloning techniques.The genome of the virus consists of 7,279 nucleotides and contains five open reading frames?ORFs?.Based on the nucleotide and amino acid sequences of the coat protein?CP?gene,the virus and White clover mosaic virus?WCMV,X16636??40.1%?and Clover yellow mosaic virus?ClYMV,D00485??37.1%?has high homology,and phylogenetic analysis indicates that the virus has the highest homology with Strawberry mild yellow edge virus?SMYEV?in the genus Potexvirus,and is identical in the phylogenetic tree.On the branch.A new virus in the genus Potexvirus of Alphaflexiviridae,named Euonymus yellow vein associated virus?EuYVAV?.This is the first report of a Potexvirus infected with the Potexvirus.?2?In October 2017,curved linear virions?1000 x 13 nm?were observed in the leaves of the yellow ring spot of a 60-year-old woody plant,Phellodendron amurense Rupr.,in Shenyang,Liaoning.A virus of the Potyviridae was amplified from diseased leaves using small RNA deep sequencing and RT-PCR molecular cloning techniques.The complete genomic sequence of the virus consists of 10,457 nucleotides and contains a typical polyprotein of the potato virus family.The virus has the highest homology with Rose yellow mosaic virus?RoYMV,NC₀19031?in the newly established Roymovirus genus of Potyviridae,and is constructed based on the complete polyprotein and coat protein gene sequences.The phylogenetic tree is on the same branch as RoYMV.The nucleotide and amino acids of the coat protein?CP?gene of the virus are 49.2% and 55.1% homologous to RoYMV,respectively,indicating that the virus is a new member of the Potyviridae family.The virus is named as Phellodendron yellow ringspot-associated virus?PYRAV?.This is the first report of a virus-infected Phellodendron amurense Rupr.plant.?3?In June 2016,symptoms of yellow vein needles were observed in a Syringa reticulata var.mandshurica samples collected in Shenyang City,Liaoning Province.Curved linear virions?580 x 13 nm?were observed under transmission electron microscopy?TEM?.A Carlavirus was amplified from diseased leaves using small RNA deep sequencing and RT-PCR molecular cloning techniques.The complete sequence of the virus was 8,525 nt and encodes six typical Carlavirus proteins.Based on the homology analysis of the genomic sequence of the virus,the virus was found to have high homology?73.2%?with the Korean isolate of Lustrum virus A?Lustrum virus,LVA?,and was constructed.The phylogenetic tree is on the same branch as the LVA.Based on the replicase protein?ReP?and coat protein?CP?genes,the homology of the virus to the nucleotide sequence of LVA is 72.2% and 74.9%,and the amino acid sequence homology is 81.4% and 86.1%.Respectively,it can be concluded that the virus is an isolate of LVA.This is the first report of LVA natural infection with Syringa reticulata var.mandshurica plants.