Detection Of Tobacco Virus Disease Transmitted By Aphids In Anhui Province And Analysis Of Genetic Diversity Of The Virus

In recent years,the occurrence of tobacco aphid-transmitted viral disease in Anhui tobacco areas has been widespread and has often caused serious damage.Therefore,this study detected virus-carrying plants and the tobacco aphid-transmitted viral diseases in Anhui tobacco area and analyzed the genetic diversity of the major tobacco aphid-transmitted viral diseases.The high-throughput sequencing and splicing techniques of siRNA were used to detect the tobacco virus in Anhui tobacco area.Disease prevention strategies lay the theoretical foundation.Details as follows:1.Detection of tobacco aphid-transmitted viral disease in Anhui tobacco area.Enzyme-linked immunosorbent assay（ELISA）detected 49 samples of the overwintering host around tobacco fields in the tobacco-planting area of Anhui Province and 402 tobacco samples with typical viral symptoms.The results showed that the host-to-virus rate was38.77%for tobacco in winter.Virus source of plants mainly include rapeseed,wheat,broad beans,cabbage,radish and so on.The detection rates of CMV,PVY and TVBMV were19.5%,14.6%,and 17%,respectively.Wheat,rapeseed,and faba bean were complex,and more than three kinds of viruses were detected.The detection rates of TMV,CMV,PVY,and TVBMV in the tobacco samples were 20.6%,29.3%,39.5%,and 8.2%,respectively.PVY had the highest detection rate,followed by CMV.PVY and CMV were the two main virus types in the tobacco area of Anhui Province.The compound infection of tobacco virus disease in Anhui Province is very complex,and there are 10 compound infection types.The most common compound infection type is CMV+PVY.2.Analysis of genetic diversity of common aphid-transmitted viruses in Anhui tobacco-growing areas.Twenty-three infected CMV samples,15 PVY samples and 22TVBMV samples were collected.The primers were designed to amplify the coat protein（CP）sequence of the virus and compared with the CP sequence reported in GenBank.The CMV,PVY and TVBMV were genetically diverse.Based on the analysis of the results,the results showed that 23 CMV isolates in Anhui belonged to subgroup IB,but within the group showed a large genetic differentiation;15 PVY isolates could be divided into PVY^N,PVY^O,and PVY^N:O.The isolates of 22 TVBMVs belonged to the third group,and most of the TVBMV isolates of Anhui had close genetic relationship with Shandong TVBMV isolates.3.Detection of tobacco virus using siRNA high throughput sequencing technology.High-throughput sequencing of small interfering RNA（siRNA）was used to identify the virus and validated by RT-PCR.The results showed that the samples of tobacco leaf malformation,chlorosis and dwarfing were affected by CMV,TVBMV and Qihuang.Infection with the virus Brassica yellows virus-strain Anhui isolate（BrYV-AH）,in which BrYV-AH is the first detected virus in Anhui tobacco,the virus genome is 5678 bp in length（MF314820）and encodes 6 open reading frames（ORFs）.It is a member of the genus Polerovirus and is a recombinant virus.At the same time,we also detected a tobacco virus,（Chilli veinal mottle virus,ChiVMV）,which was first discovered in Anhui tobacco area.The infested tobacco showed yellow spots,leaf curls,and distorted leaf blades.The results of the study clarify the symptoms of ChiVMV infecting Anhui Yunyan 97 cultivars.