玉米叶片中甘蔗花叶病毒检测及其基因组3'端序列分析

Detection of Sugarcane Mosaic Virus in Maize and Analysis of 3′Terminal Sequence of Its Genome

在云南元谋采集的玉米叶片样品上获得一病毒分离物,经生物学(摩擦接种)、血清学(DAS-ELISA)和分子生物学(RT-PCR)鉴定,确定为甘蔗花叶病毒(Sugarcane Mosaic Virus,SCMV)。为分析其基因组3′端特性,以叶片中提取的总RNA为模板,对基因组3′端进行RT-PCR扩增,产物克隆到pMD18-T载体上进行序列分析。结果表明,SCMV基因组3′端序列包含了非编码区254个碱基和编码蛋白的1 578个碱基。运用Mega4.1构建进化树,系统进化树表明,除SCMV-Spain2外,其余分离物可明显的划分为2个群体:第Ⅰ群体包括分离物SCMV-SHANDONG,SCMV-SHANXI与SCMV-HENAN;第Ⅱ群体包括SCMV-Mexico和SCMV-Spain1。直观地看,SCMV分离物之间的系统进化关系和地理分布有一定的联系,SCMV-SHANDONG与SCMV-HENEN分离物关系很近,而SCMV云南分离物距离相对较远。其原因可能是云南分离物与中国其他地区分离物具有一个距今较近的共同祖先。

A virus isolate was obtained from the maize leaves sample collected from Yuanmou of Yunnan,which was identified as sugarcane mosaic virus（SCMV） by biological method（mechanical inoculation）,serological method（DAS-ELISA） and molecular biological method（RT-PCR）.To analyze the features of 3′terminal sequence of SCMV genome,taking total RNA extracted from maize leaves as template to amplify the 3′terminal sequence of SCMV genome by RT-PCR,then the products were cloned into pMD18-T vector for sequence analysis.The results showed that the 3′terminal sequences of SCMV genome contains 254 bp bases of 5′UTR and 1 578 bases of encoded protein.The phylogenetic tree,constructed by Mega4.1,indicated that except SCMV-Spain2,other isolates could be divided into two distinct groups： the groupⅠincludes SCMV-SHANDONG,SCMV-SHANXI and SCMV-HENAN;the groupⅡ includes SCMV-Mexico and SCMV-Spain1.The phylogenetic tree also showed that SCMV isolates have a certain contact between the geographical distribution and phylogenetic relationships： the SCMV-SHANDONG has a close relationship with SCMV-HENEN,but a relatively far distance with SCMV-Yunnan.It may because SCMV-Yunnan has a common ancestor with the isolates from other regions in China.