作　　者： ; ; ; ;

机构地区： 华南农业大学

出　　处： 《作物学报》 2008年第11期1916-1920,共5页

摘　　要： 为探明甘蔗花叶病的病原病毒之一高粱花叶病毒（sorghum mosaic virus，SrMV）在我国华南地区的发生情况，从广东广州、翁源、博罗及广西南宁等地甘蔗产区采集表现花叶症状的甘蔗叶片样品，采用1对病毒CP基因引物（P1：5′-ACAGCAGAWGCAACRGCACAAGC-3、P2：5′-CTCWCCGACATTCCCATCCAAGCC-3′，Y=C／T，W=T／A，K=G／T,R=A／G），进行一步法RT-PCR检测，结果表明48％的样品受到SrMV侵染。根据寄主类型和地理来源，选取10份代表性样品，对经P1、P2扩增获得的病毒CP基因片段进行直接测序，所得序列经Blast比对确认均为SrMVCP序列。为揭示SrMV种内的遗传多样性，采用Clustal W方法对本文鉴定的10个SrMV分离物与GenBank中已报道的全部18个SrMV株系或分离物的CP基因序列进行多序列联配，并计算核苷酸同一性，结果显示各个SrMV分离物之间的CP基因核苷酸同一性为76％～100％。基于病毒CP基因核苷酸同一性的遗传多样性分析，SrMV种内分化成2个遗传变异类群，即杂种甘蔗组（HS group）和高贵甘蔗组（Nsgroup），它们的分离物大多分别来自杂种甘蔗（hybrid sugarcane）寄主和高贵甘蔗（noble sugarcane）寄主。分离物之间的平均CP基因核苷酸同一性，在两组组内分别为87％和90％，两组间为80％。说明两组SrMV之间存在较大的遗传差异，寄主隔离是导致该病毒种内分化的主要因素。因此，在甘蔗花叶病的防治和抗病毒育种工作中，除需注意病原的种类和寄主类型外，还应充分考虑病原种内的遗传多样性。 In order to understand the occurrence of sorghum mosaic virus （SrMV）, one of pathogenic virus causing sugarcane mosaic disease in south China, sugarcane leaf samples with mosaic symptom were collected from commercial growing fields in Guangzhou, Wengyuan, Boluo of Guangdong province and Nanning of Guangxi province. The virus was detected by one-step RT-PCR with SrMV specific primers P1 （5′-ACAGCAGAWGCAACRGCACAAGC-Y） and P2 （5′-CTCWCCGACATTCCCAT CCAAGCC-Y, Y=C/T, W=T/A, K=G/T, R=A/G） based on the viral coat protein （CP） gene. The results showed that 48% samples were infected with SrMV. Ten amplified cDNA products were chosen based on host and geographic origin for direct sequencing. BLAST analysis revealed that they were all homologous to reported SrMV CP gene. To investigate the genetic diversity within the species SrMV, multiple alignment analysis of CP gene nucleotide sequences of the 10 SrMV isolates, together with all 18 SrMV isolates documented in GenBank up to date, was perfermed using Clustai W algorithm. It was showed that 28 SrMV isolates were clustered into two groups, namely hybrid sugarcane （HS） group and noble sugarcane （NS） group. The average CP gene nucleotide identities were 80% between groups, and 87% and 90% between isolates within HS and NS groups, respectively. Coincidently, most isolates in HS group were from hybrid sugarcane, whereas most isolates in NS group from noble sugarcane. This implies that SrMV has evolved under host selection. Hence, not only different pathogens and host types, but also the virus genetic diversity should be taken into consideration in sugarcane mosaic disease controlling and virus-resistance breeding.

关 键 词： 甘蔗花叶病 高粱花叶病毒 遗传分化

领　　域： [农业科学] [农业科学] [农业科学] [农业科学] [农业科学]