蚕豆萎蔫病毒2号山西分离株的全基因组序列测定与分析

Identification and Analysis of Complete Genomic Sequence of Broad bean wilt virus 2 Shanxi Isolate

本试验在生物学接种的基础上,利用非序列依赖性PCR扩增（sequence-independent amplification,SIA）对感病青椒（Capsicum annuum）进行了分子鉴定.序列测定及分析发现,侵染青椒的病毒为蚕豆萎蔫病毒2号（Broad bean wilt virus 2,BBWV2）.为明确BBWV2青椒分离物（BBWV2-Ca）的分类地位,对BBWV2-Ca的全基因组序列进行了分段克隆、序列测定和分析.BBWV2-Ca RNA1全长5 929 bp,含有1个ORF.BBWV2-Ca RNA2全长3 559 bp,含有1个ORF,编码3种蛋白：VP53/VP37、外壳蛋白大亚基（large coat protein,LCP）和外壳蛋白小亚基（small coat protein,SCP）.全序列核苷酸同源性分析显示,BBWV2-Ca RNA1与BBWV2其它分离物核苷酸同源性在77.9%-93.7%之间;RNA2与BBWV2其它分离物核苷酸同源性在80.2%-93.8%之间.全序列系统进化分析显示,BBWV2-Ca RNA1与BBWV2-XJ14-3以及BBWV2-RP3株系聚为一簇,亲缘关系最近;RNA2与BBWV2-Am形成一个独立分支,亲缘关系最近.

To identify the viruses that induced Capsicum annuum disease, biological inoculation and sequence-independent amplification （SIA）were used. Results of SIA and sequencing showed that there was Broad bean wilt virus 2 （BBWV2） in Capsicum annuum leaves. To further characterize the BBWV2 isolate Capsicum annuum （BBWV2-Ca）, the complete sequence of BBWV2-Ca was cloned and determined. BBWV2-Ca RNA1 comprised 5 929 bp nucleotides with one ORF. BBWV2-Ca RNA2 comprised 3 559 nucleotides with one ORF and it encoded 3 kinds of proteins, VP53/VP37, large coat protein and small coat protein. Nucleotide sequence similarity searches showed that BBWV2-Ca RNA1 and RNA2 were from 77.9% to 93.7% and from 80.2% to 93.8 % to that of other BBWV2 strains, respectively. Phylogenetic comparisons based on amino acid sequences showed that BBWV2-Ca RNA1 formed an independent branch with BBWV2-XJ14-3 and BBWV2-RP3. BBWV2-Ca RNA1 was most closely related to BBWV2-XJ14-3 and BBWV2-RP3. BBWV2-Ca RNA2 formed an independent branch with BBWV2-Am. Therefore, BBWV2-Ca RNA2 was most closely related to BBWV2-Am.