侵染广东甘薯的甘薯曲叶病毒分子检测与鉴定

Molecular detection and identification of Sweet potato curl leaf virus infecting sweet potato in Guangdong Province

甘薯曲叶病是广东甘薯的一种新病害,病株表现为叶片皱缩,向上卷曲,叶脉肿大等症状。PCR检测结果显示,所有病样中均存在菜豆金色花叶病毒属病毒。通过滚环扩增方法获得了3个病毒分离物的全基因组。扩增产物克隆及序列分析结果表明,这3个病毒分离物基因组均仅含有DNA-A,具有菜豆金色花叶病毒属单组分病毒基因组典型特征;其大小分别为2 829nt(JX286653、JX286654)和2 828nt(JX286655)。三者核苷酸序列同源率为96.0%～98.4%;与已报道的甘薯曲叶病毒19个分离物的同源率均大于89.0%。因此,引起广东甘薯曲叶病的病原被鉴定为甘薯曲叶病毒。本研究是首次在广东发现甘薯曲叶病毒。

The sweet potato leaf curl disease is a new disease in Guangdong. The symptoms of the diseased plants exhibited leaf shrinking,curling upwards and vein swelling. PCR detection indicated that the diseased plants were infected by a begomovirus. Using rolling circle amplification （RCA） method, the full-length DNA-A of three be gomovirus isolates were amplified, cloned and sequenced. The results revealed that they only had DNA-A compo nent, with typical characteristics of monopartite begomoviruses and 2 829 nucleotides （GenBank accession nos. JX286653 and JX286654） and 2 828 nucleotides （GenBank accession no. JX286655） in length, respectively. The nucleotide identities of these three DNA-A were 96.0%--98.4% between each other and more than 89.0% with these of 19 isolates of Sweet potato curl virus previously reported. Thus, the virus infecting sweet potato in Guang dong was identified as Sweet potato curl virus. It was the first report that the Sweet potato curl leaf virus was dis tributed in Guangdong Province, China.