华南地区甘蔗黄叶病发生及甘蔗绵蚜传毒特性研究

Occurrence of Sugarcane Yellow Leaf Virus in South China and its Transmission by the Sugarcane-Colonizing Aphid, Ceratovacuna lanigera

【目的】明确甘蔗黄叶病毒(sugarcane yellow leaf virus,SCYLV)在华南地区的发生与危害情况,检验华南地区甘蔗上普遍发生的甘蔗绵蚜的传毒特性。【方法】对华南地区多个甘蔗产区主要甘蔗品种黄叶病发生情况进行田间调查,采用RT-PCR技术扩增病毒CP基因并对扩增产物进行测序分析,建立能够检出单头蚜虫及侵染早期未现症植株体内SCYLV的巢式RT-PCR检测技术,测定甘蔗绵蚜传毒寄主范围及传毒效率。【结果】华南地区果蔗和糖蔗均已受到SCYLV的侵染,大多田块病株零星分布,病株率0.5%～10%,但少数田块病株率超过80%。大多数SCYLV分离物CP基因核苷酸序列与SCYLV巴西分离物(SCYLV-B1)相应基因序列高度同源。甘蔗绵蚜除能在甘蔗植株间高效传播SCYLV外,还可将病毒传至高粱、水稻及玉米幼苗,但未能传至小麦和香蕉。【结论】SCYLV为近年自境外传入的甘蔗病毒病原,已在华南多个蔗区有分布,目前仅处于零星发生状态。首次证实甘蔗绵蚜是SCYLV传播媒介,能将病毒传至高粱、水稻和玉米等其它禾本科作物。SCYLV的潜在威胁应引起足够重视。

[Objective] The objective was to investigate the distribution of the sugarcane yellow leaf virus （SCYLV） and its transmission through the predominant sugarcane-colonizing aphid, Ceratovacuna lanigera, in south China. [Method] A field survey was conducted in south China sugarcane farm to monitor the occurrence of sugarcane yellow leaf disease. The viral pathogen was identified by CP gene RT-PCR amplification and sequencing. The nested RT-PCR technique was developed for SCYLV detection in individual viruliferous aphid and in the early stages of plant infection. C lanigera was tested for vector efficiency to transmit SCYLV to sugarcane and some other crops. [Result] Both Succharum officinarum for chewing and S. inter-specific hybrids for sugar production growing in south China were infected by SCYLV. The percentage of diseased plants was 0.5%-10%, and insome fields the highest was 80%, though seldom found. Nucleotide sequences of viral CP coding regions amplified by RT-PCR from most diseased samples displayed high homology with SCYLV B1 strains isolated from Brazil. C. lanigera, the predominant aphids species on sugarcane in south China, was conformed as a new vector for SCYLV. It could efficiently transmit SCYLV to sugarcane, sorghum, rice and maize seedlings, though not to wheat and banana. [Conclusion] SCYLV is an exotic virus invaded into south China in recent years. To date, it has spread in several low disease incidence sugarcane farms It can be transmitted by C. lanigera not only between sugarcane plants but also among several other gramineous crops. Its potential risks for sugarcane and other crops should be inspected.