重庆市萝卜芜菁花叶病毒的检测与序列分析

Detection and sequence analysis of CP gene of Turnip mosaic virus (TuMV) infecting radish plants in Chongqing City

为明确重庆市萝卜感染芜菁花叶病毒(Turnip mosaic virus,TuMV)的情况,在重庆市巴南区、九龙坡区、北碚区等14个区县共采集了146份萝卜病毒病样品,采用酶联免疫吸附试验法(enzymelinked immunosorbent assay,ELISA)对病样进行TuMV检测,并通过PCR、克隆和测序等技术获得13个TuMV分离物CP核苷酸序列,利用软件分析重庆市TuMV CP基因序列的相似性,利用系统进化树分析CP基因遗传变异与系统进化。结果表明,共有105份样品的TuMV检测为阳性,检出率为71.9%;所得13个分离物CP基因均为864 bp,测序的13个分离物CP核苷酸相似性为89.1%~99.2%,与国内已报道的TuMV各分离物CP核苷酸相似性在88.3%~99.4%之间;所得的13个分离物均分布在basal-BR和world-B组中,在Asian-BR和basal-B组中均无分布,进一步分析发现有9个分离物属于word-B组,仅4个分离物属于basal-BR组。研究表明,TuMV在重庆市萝卜各种植区普遍发生,且word-B组为重庆市萝卜的优势毒源。

One hundred and forty-six diseased radish plants with typical viral symptoms were collected from 14 counties in Chongqing City. They were tested by ELISA to observe the disease occurrence of Turnip mosaic virus（TuMV） on radish in Chongqing City. The CP genes of 13 TuMV isolates were cloned and sequenced, and the sequence similarities were analyzed by using software, and phylogenetic trees were constructed. The detection results showed that 105 samples were infected by TuMV, accounting for 71.9% of total samples. Sequencing results showed that the full-length of TuMV-cp of these 13 isolates was 864 bp. Alignment analysis indicated that these isolates shared 89.1%-99.2% sequence similarity, while their similarity with reported sequences of different geographic origins was 88.3%-99.4% at nucleotide level. Chongqing isolates clustered in the basal-BR and world-B, while no isolates were present in Asian-BR or basal-B. Nine isolates belonged to world-B and only four isolates belonged to basal-BR. These results revealed that TuMV is a common pathogen of radish and world-B is the dominant group of TuMV infecting radish crops in Chongqing City.