重庆辣椒上烟草轻型绿花叶病毒的分子检测及全基因组克隆分析

辣椒是重庆重要的经济作物,烟草轻型绿花叶病毒(Tobacco mild green mosaic virus, TMGMV)引起的病毒病对辣椒生产造成了严重影响.为明确TMGMV在重庆辣椒上的发生、分布情况及其基因组特征,从重庆北碚、石柱、潼南和九龙坡4个区县采集29份疑似病毒病样品进行了RT-PCR鉴定,通过分段扩增测序的方法拼接获得病毒基因组全序列并进行了系统进化分析.检测结果表明:29份样品中有9份检测到TMGMV,检出率为31.03%,其中石柱县的检出率最高,为60.00%.序列分析发现,重庆辣椒分离物TMGMV-TN29基因组全序列具有烟草花叶病毒属(Tobamovirus)病毒典型基因组结构特征,由6 356 nt构成.系统进化分析得出,该分离物与TMGMV厦门分离物Xiamen (JX534224)具有较近的亲缘关系,核苷酸序列相似性达到99.75%.

Molecular Detection and Cloning and Sequence Analysis of the Complete Genome of Tobacco mild green mosaic virus on Pepper Plants in Chongqing

Pepper (Capsicum annuum L.) is one of the most important cash crops in Chongqing, Tobacco mild green mosaic virus (TMGMV) causes a virus disease in pepper, which brings serious damage to pepper production. To understand the distribution of TMGMV and its genomic characters in Chongqing, leaf samples with mottle, mosaic and distort symptoms were collected from Beibei, Shizhu, Tongnan and Jiulongpo Districts of Chongqing and determined by RT-PCR. The complete genomic sequence of TMGMV was obtained by assembling four fragments amplified from the positive samples by RT-PCR which overlapped the whole TMGMV genome. The results of RT-PCR showed that of the 29 samples 9 were positive, with a detection rate of 31.03%. The detection rate of TMGMV in Shizhu County was the highest, 60.00%. The complete genome sequence analysis revealed that TMGMV of Chongqing isolates consisted of 6, 356 nucleotides with the typical characteristics of the genome of the genus Tobamovirus. Phylogenetic analysis based on TMGMV genome showed that TMGMV-TN29 had a close phylogenetic relationship with isolate Xiamen (JX534224), and they shared a sequence similarity of 99.75%.