蚕豆萎蔫病毒2的分子鉴定及RNA1组分5′末端核苷酸序列分析

Molecular Identification of BBWV2 and Sequence Analysis of 5′-Terminal Region of Genomic RNA1

用蚕豆病毒属(Fabavirus)的兼并引物Fab5′R1F和Fab5R′1R对自然感病的4株加工番茄、1株辣椒和2株一串红病株进行RT-PCR,将扩增到的长约400bp的片段进行克隆和测序。结果发现:来自7个病株的9个病毒分离物均为蚕豆萎蔫病毒2(BBWV-2)基因组RNA1组分5′末端的353～392个核苷酸;同源性比较表明,9个序列之间的同源性为90.4%～99.2%,与已报道的BBWV2的同源性为89.5%～95.9%。序列比对发现,BBWV2基因组RNA1组分5′末端非编码区包含了由11个碱基(AAACAGCUUUC)组成的重复序列,而分别来自加工番茄分离物XJ14-1b和一串红的分离物S12在重复序列区段内比其它所有分离物缺少了包括2个重复序列在内的36个碱基。

Seven samples showing typical viral symptoms collected from processing tomato,chili and Salvia splendens were detected by RT-PCR using universal primer pair Fab5′R1F and Fab5R′1R for Fabavirus.The PCR products of about 400 bp were cloned and sequenced.The sequences of nine virus isolates from seven infected plants were determined to be 353～392 nucleotides,and they were 5′-terminal sequence of genomic RNA1 of BBWV2.The nine isolates shared 90.4%～99.2% nucleotide sequence identities and had 89.5%～95.9% sequence identities with other reported isolates of BBWV2.Sequence analysis showed that RNA-1 of BBWV2 had a 5′-non-coding region,which contained the repeated motif AAACAGCUUUC.Isolate XJ14-1b from processing tomato and isolate S12 from Salvia splendens lacked 36 nucleotides including two repeated motif in 5′-non-coding region,compared with other RNA1 of BBWV2.