Molecular Identification And Genetic Diversity Analysis Of Sugarcane Mosaic Pathogeny In Yunnan Province

Sugar is a pillar industry in border areas of Yunnan to develop regional economics and reducepoverty. In recent years, sugarcane mosaic disease in Yunnan main producing areas became widespreadand serious, resulting in decreased production, lower quality, seriously restricting sustainabledevelopment of Yunnan sugar industry.145samples with mosaic phenotype were collected fromBaoshan, Dehong, Honghe, Lincang, Simao, Xishuangbanna, Yuxi, Zhaotong, the eight main producingareas and the National Sugarcane Germplasm Resources Garden, and detected by RT-PCR. Three kindsof pathogens were detected in the145samples: Sugarcane mosaic virus (SCMV), Sorghum mosaicvirus (SrMV) and Sugarcane streak mosaic virus (SCSMV), while the detection rate of SrMV was64.13%, as the main pathogen, SCMV and SCSMV were higher in the samples from the NationalSugarcane Germplasm Resources Garden reached62.5%and77.78%. Field varieties were SrMVmainly, and SCMV was detected in the National Sugarcane Germplasm Resources Garden and Baoshan,Honghe. Part of the original species cultivated varieties existed SrMV and SCMV complex infectionphenomenon. SCSMV was found in the National Sugarcane Germplasm Resources Garden, Yuxi,Dehong.Selected27SrMV-positive and3SCMV-positive samples cloned and sequenced the CP gene toanalysis SrMV of SCMV who causes genetic diversity of Yunnan sugarcane mosaic disease. Sequenceanalysis showed that: the sequence of SrMV CP gene was with large differences. There were multiplelines, and multiple strains in the same area, but no significant geographic differences, while there wasno SCMV strain differentiation. The nucleotide sequences of SrMV CP gene had a similarity of only77%-79%, probably due to the existence of a new species of sugarcane mosaic virus.9SCSMV positive samples were cloned and sequenced the cp gene, and the results showed highhomology between them. Downloaded the sequence of SCSMV CP gene from NCBI, then clusteranalyzed with the9isolated SCSMV CP gene sequences obtained in this experiment, the result showedthat: SCSMV can be divided into a number of different lines, and their geographic differences wereobvious. The9isolates obtained in this study were formed a single branch may represent a line ofSCSMV.According to the sample collection sites, choose the6isolates, M2, M3, M6, M9, M17and M32,which were RT-PCR positive and host of the Red River, Baoshan, Dehong, Xishuangbanna, Simaosugarcane cultivars, identified host determination, and finally found that they had significantly differentpathogenicity, while isolates M3had the widest range of differential hosts and strong pathogenicity.