广东省番茄黄化曲叶病毒的分子鉴定及序列分析

番茄黄化曲叶病毒病是世界番茄生产上一种毁灭性病害,番茄黄化曲叶病毒Tomato yellow leaf curl virus(TYLCV)是引起该病害的主要病原病毒之一。本文采用滚环扩增及基因克隆方法,获得了侵染广东佛山和肇庆番茄的TYLCV 4个分离物全基因组;它们均为2 781 nt,编码6个ORF,其中病毒链上编码AV1和AV2,互补链上编码AC1、AC2、AC3和AC4。同源性比较结果表明,4个广东分离物基因组序列两两间同源性为99%以上;与已报道的TYLCV各分离物同源性在90%以上,而与来自中国不同地区的TYLCV分离物的同源率均在98%以上。系统进化分析显示,广东分离物与来自中国不同地区的TYLCV分离物亲缘关系较近,并聚类在一个分支。因此,侵染引起广东佛山和肇庆番茄黄化曲叶病的病毒应来自国内其他地区。本研究是对TYLCV广东分离物分子特征的首次报道。

Molecular identification and sequence analysis of Tomatoyellow leaf curl virus in Guangdong province

Tomato yellow leaf curl disease is a destructive disease in tomato production. Tomato yellow leaf curl virus (TYLCV) is one of the main pathogens causing TYLCD. Four whole genome sequences of TYLCV from infected tomato in Foshan and Zhaoqing, Guangdong province were obtained by rolling circle amplification and gene cloning methods. The four genome sequences were 2 781 nucleotides (nt) in length and encoded six potential ORFs. The AV1 and AV2 were located on the virion sense DNA strand, whereas the AC1, AC2, AC3, AC4 were located on the complementary sense strand. The results of homology comparison showed that the genomic sequences of four isolates from Guangdong shared >99.0% nt identities with each other, and shared > 90% nt identities with all isolates of TYLCV in the database, > 98% nt identities with all TYLCV isolates from China. Phylogenetic analysis of the four Guangdong isolates and the other isolates of TYLCV indicated that they clustered with all TYLCV isolates from China to form a unique clade. Therefore, the viruses infecting tomato in Foshan and Zhaoqing, Guangdong likely come from other areas of China. This is the first molecular characterization of TYLCV infecting tomato in Guangdong province, China.