草莓轻型黄边病毒中国分离物全基因组序列测定和分析

Complete Genome Sequence of Strawberry Mild Yellow Edge Virus Isolated in China

草莓轻型黄边病毒(Strawberry mild yellow edge virus,SMYEV)是引起我国草莓病毒病害的重要病毒之一,我们测定了共侵染草莓植株的2个SMYEV中国分离物FJ1和FJ2的全基因组序列。FJ1和FJ2分离物基因组全长均为5971 nt,包含5个开放阅读框(ORF),其中,FJ2分离物ORF4编码蛋白C端缺乏7 aa。SMYEV分离物FJ1和FJ2的基因组核苷酸序列一致性为89.8%,两者和其他SMYEV分离物的基因组核苷酸序列一致性分别为83.7%~89.8%和84.1%~90.0%;基于CP基因的系统进化分析表明,SMYEV分离物分为2个大组群4个亚群,FJ1和FJ2分别归属不同的组,两者具有较远的亲缘关系,其中FJ1与中国分离物sy01和sy04、日本分离物T1以及韩国分离物KNS1亲缘关系最近,FJ2与中国分离物sy02、加拿大一株分离物PEI113_12以及日本分离物T2亲缘关系最近。RDP4重组分析表明,FJ1和FJ2均存在潜在的重组事件。本研究首次报道了我国SMYEV基因组全长序列,为该病毒在我国的侵染流行、检测和防控提供了理论基础。

Strawberry mild yellow edge virus(SMYEV)is one of the major viruses threatening strawberry production in China.Here,we present the complete genome sequences of two new divergent SMYEV isolates(FJ1 and FJ2)co-infecting a single strawberry plant,both sequences comprised 5,971 nt and contained five open reading frames(ORFs),and the FJ2 ORF4 lacked the C-terminal 7 amino acid residues and encoded a putative truncated protein.Genomic nucleotide sequence identity between FJ1 and FJ2 was 89.8%,and the genomic nucleotide sequence identities between the two isolates and other reported isolates were 83.7%-89.8%and 84.1%-90.0%,respectively.Phylogenetic analysis based on the coat protein gene sequences indicated that SMYEV isolates from diffident countries were divided into two distinct groups with four subgroups.FJ1 and FJ2 represented two SMYEV groups,FJ1 was closely related to Chinese isolates sy01 and sy04,Japanese isolate T1 and Korean isolate KNS1,and FJ2 was closely related to Chinese isolate sy02,Canadian isolate PEI113_12 and Japanese isolate T1.Recombination analysis suggested that recombination events occurred in SMYEV FJ1 and FJ2 isolates.This is the first report of the complete genome sequences of SMYEV isolated in China.This study provides a theoretical basis for SMYEV prevalence,diagnosis,and control in China.