贵州烟田马铃薯Y病毒优势株系全序列克隆及系统进化分析

为了解马铃薯Y病毒在贵州烟田的发生和流行规律,对2013—2015年采集到的贵州省多个烟区呈现典型茎脉坏死症状的疑似受马铃薯Y病毒(Potato virus Y,PVY)侵染的烟草样品进行单斑分离和病毒鉴定,并以现有PVY序列信息为参考,设计了4对PVY特异引物,经过RT-PCR扩增、T载体连接、序列测定以及序列拼接,并利用MEGA软件进行系统进化分析。结果发现PVY福泉分离物(PVY Fuquan isolate,PVY-FQ)和PVY大方分离物(PVY Dafang isolate,PVY-DF)为优势株系并获得了PVY-FQ和PVY-DF的全基因组序列。PVY FQ整条基因组由9 699个碱基组成,编码多聚蛋白的开放阅读框位于第188~9 373nt;PVY DF整条基因组由9 706个碱基组成,编码多聚蛋白的开放阅读框位于第190~9 375nt。2条序列的基本特征与已报道PVY基因组一致。对PVY-FQ和PVY-DF全序列与已报道PVY序列进行系统进化分析发现,PVY-FQ与PVY NTN株系具有较高的亲缘关系,而PVY-DF与PVYN具有较高亲缘关系。

Full sequence cloning and phylogenetic analysis of Potato virus Y predominant strains collected from tobacco field in Guizhou Province

Studies on virus genome variation are necessary for virus disease prediction and control.During 2013-2015,tobacco samples which showed typical vein necrosis symptom were collected from Guizhou Province.Four pairs of specific primers were designed from the conserved regions of published genome sequences of Potato virus Y (PVY).After total RNA extraction,RT-PCR,molecular cloning and sequencing,the data of PVY genome sequence was then used for phylogenetic analysis by MEGA software.The result suggested that two PVY strains,PVY-FQ and PVY-DF,which were collected in tobacco plants from Fuquan area and Dafang area respectively,were confirmed as dominant isolates.Genome sequence analysis showed that PVY-FQ and PVY-DF contained 9 699 and 9 706 nt,of which their unique ORF located in 188-9 373 and 190-9 375 nt respectively.PVY-FQ and PVY-DF were confirmed sharing common genome structure with other isolates published previously.Phylogenetic analysis suggested that PV-FQ had high homology with PVY^NTN strain,while PVY-DF had high homology with PVY^N strain.