广东黄秋葵黄脉曲叶病样中检测到烟粉虱传双生病毒

黄秋葵是近几年来从日本和我国台湾引进的一种蔬菜作物。近期，广东的黄秋葵上发生了黄脉曲叶病。病株的典型症状表现为叶脉黄化，在叶片正面形成网络状，在叶背面叶脉肿大突起明显，病株幼叶小且向下卷曲，甚至整片幼叶黄化。植株早期被感染表现矮化。在发生黄脉曲叶病的黄秋葵田间，其病株率高达60%以上。用烟粉虱传双生病毒简并引物对随机采集的病样进行PCR检测，从这些病样中均能扩增出1条预期大小为570 bp的特异片段；基因克隆及测序分析结果表明，与该特异片段同源的均属双生病毒科菜豆金色花叶病毒属病毒DNA，其中与木尔坦棉花曲叶病毒（Cotton leaf curl Multan virus， CLCuMV）分离物G6相似性最高，为99%。这些研究结果表明，广东黄秋葵黄脉曲叶病中存在烟粉虱传双生病毒，该病害可能也是由CLCuMV侵染引起的。

Detection of whitefly-transmitted geminivirus associated with the okra yellow vein leaf curl disease in Guangdong

Okra is a vegetable crop introduced from Japan and Taiwan of China.Recently,the okra yellow vein leaf disease(OYVLD)has been found in Guangdong.The characteristic symptoms of the disease were yellow vein.interwoven network of yellow veins on the surface of leaves and obvious vein swelling on the back surface of Ieaves.The young leaves of the diseased plants were curling and their size Was reduced.In extreme cases,the infected leaves became totally yellow.Plants infected during the early stages remained stunted.In the fields,the rate of diseased plants Was more than 60%.Using the degenerate primers of whitefly-transmitted geminiviruses,the diseased samples collected randomly from fields were detected by PCR.The results showed that the expected 570 bp specific fragment Was amplified from all diseased samples.The specific fragment Was cloned and sequenced.BLAST results showed that all sequences homologous to the specific fragment belonged to the genus Begomovirus of the family Geminiviridae.and there was the highest similarity(99%)between the sequence of the specific fragment and DNA-A of Cotton leaf curl Multan virus(CLCuMV)isolate G6.These findings suggested that there were whitefly-transmitted geminiviruses in OYVLD samples from Guangdong,and the OYVLD was probably caused by CLCuMV.