安徽省太和县中国南瓜曲叶病毒自然侵染南瓜的检测分析

Detection and analysis of squash leaf curl China virus naturally infecting pumpkin in Taihe,Anhui province

中国南瓜曲叶病毒(squash leaf curl China virus,SLCCNV)是一种植物单链DNA病毒,属于双生病毒科Geminiviridae菜豆金色花叶病毒属Begomovirus。在自然条件下该病毒可以侵染多种葫芦科作物,如南瓜、甜瓜等。该病毒由烟粉虱进行持久性传播,是影响瓜类产量和品质的重要病害。2021年4月-5月,安徽省太和县温室大棚中的南瓜叶片出现斑驳、皱缩、卷曲以及植株矮化等现象,我们采集了具有典型病毒病症状的南瓜病叶样品以及烟粉虱虫体进行RT-PCR鉴定,结合测序结果鉴定危害南瓜的病毒为SLCCNV。为了进一步明确安徽太和地区SLCCNV的系统进化特征,我们测定了SLCCNV的外壳蛋白基因(coat protein,CP)序列并进行系统发育分析,结果表明安徽太和县所检测到的SLCCNV分离物与中国广东和海南地区的分离物亲缘关系较近,并且与越南、菲律宾、柬埔寨、泰国等一些国家的分离物处于同一个大分支,存在较小的地域差异性,而与印度和孟加拉国地区的分离物亲缘关系相对较远,处于不同的大分支。本研究是安徽省SLCCNV侵染南瓜的首次报道,期望为该病害的预警和防控提供理论依据。

Squash leaf curl China virus(SLCCNV) is a single-stranded DNA virus,belonging to the genus Begomovirus in the family of Geminiviridae.SLCCNV can infect many cucurbits under natural conditions,such as pumpkin,melon,etc.The virus is persistently transmitted by Bemisia tabaci and causes an important disease that affects the yield and quality of melons.From April to May 2021,pumpkin leaves in greenhouses in Taihe county,Anhui province appeared mottled,shrunken,curled,and plant dwarfing.We collected samples of diseased leaves with typical symptoms and Bemisia tabaci for RT-PCR detection and identification.Sequence analysis showed that this virus isolate was SLCCNV.To clarify the variation of SLCCNV in Taihe,Anhui province,the coat protein gene nucleotide sequence of the virus was determined for phylogenetic analysis.The results show that the isolate is relatively close to isolates from Guangdong and Hainan,and clustered with isolates of SLCCNV from Vietnam,Philippines,Croatia,Thailand and other countries.There are small regional differences among them.The isolates of Taihe,Anhui have a distant relationship with the isolates of India and Bangladesh,and they are in different branches.This study is the first report of SLCCNV infection of pumpkins in Anhui province,which can provide a theoretical basis for the early warning and prevention of the disease.