Detection of the viruses causing sugarcane mosaic disease and molecular identification of an isolate of them in Yunnan

Sugarcane mosaic disease has been occurring widely in Yunnan. 28 sugarcane mosaic disease samples from the leading varieties of six different growing areas were detected by electron microscope. Flexous fila-mentous particles were found in the sap of 25 isolates, pin-wheel and cylindrical inclusion bodies were produced in infected leaf tissues. These 25 isolates were detected by indirect ELISA, 16 ones could react to antibody of Potyvirus, but others couldn’t. According to the sugarcane growing areas and local leading varieties, 7 isolates were selected to perform diagnostical host testing. The results showed diagnostical host range and pathogenicity of them were different, isolate HH-1 had the most extensive host range and strong pathogenicity. 3′terminal sequence of HH-1 genomic RNA was cloned and sequenced. The sequence analysis showed that coat protein(CP) gene of HH-1 contained 864 nucleotides, encoded 287 amino acids. It had a highest identity (97.7%) of amino acid sequence with Sorghum mosaic virus(SrMV), for which HH-1 was inferred as an isolate of SrMV.