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

【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.