侵染中国陕西南瓜的中国南瓜曲叶病毒的鉴定和全基因组分析

Identification and complete genome sequence analysis of squash leaf curl China virus infecting squash in Shaanxi,China

为明确南瓜叶片上卷、黄化的症状是否由病毒侵染引起,本研究采用小RNA深度测序对采集自陕西地区的南瓜叶片样品进行了鉴定。结果显示,侵染南瓜样品的病毒可能是中国南瓜曲叶病毒(squash leaf curl China virus,SLCCNV)。经PCR扩增并且克隆测序获得了病毒的DNA-A和DNA-B组分的全基因组序列。序列比对发现,所克隆的DNA-A组分与SLCCNV海南分离物(SLCCNV-Hn61)DNA-A的一致性最高,为99.1%;DNA-B组分与SLCCNV-Hn61和三亚分离物SLCCNV-SY的DNA-B组分一致性最高,为96.8%。系统进化树分析发现所克隆的DNA-A和DNA-B组分分别与SLCCNV-Hn61和SLCCNV-SY的亲缘关系最近。以上研究结果表明侵染陕西南瓜叶片的病毒是SLCCNV的分离物。这是首次报道SLCCNV在陕西地区的危害,研究结果为当地经济作物南瓜的病害防控提供参考。

To determine whether the leaf curling and yellowing symptoms of pumpkin plants are caused by virus infection,small RNA-based deep sequencing was performed in this study.Analysis of the deep sequencing data indicated that the collected pumpkin plants were potentially infected by squash leaf curl China virus(SLCCNV).The complete genome sequences of DNA-A and DNA-B components were obtained by PCR amplification,cloning,and sequencing.Sequence comparison showed that the DNA-A component shared the highest sequence identity(99.1%)with the Hainan isolate of SLCCNV(SLCCNV-Hn61),and the DNA-B component had the highest sequence identity(96.8%)with SLCCNV-Hn61 and the Sanya isolate of SLCCNV(SLCCNV-SY).Phylogeny analysis showed that the complete genome sequences of DNA-A and DNA-B components were most closely related to the Hainan and Sanya isolates of SLCCNV,respectively.These results suggest that the virus identified in this study is an isolate of SLCCNV.This is the first report of the occurrence of SLCCNV in Shaanxi,China,which provides a reference for the prevention and control of the local pumpkin disease.