Location: Sugarcane ResearchTitle: Identification of genetic diversity among isolates of Sorghum mosaic virus from Louisiana sugarcane
Submitted to: American Society of Sugar Cane Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2019
Publication Date: 6/1/2019
Citation: Grisham, M.P., Warnke, K.Z., Maggio, J.R., Mollov, D.S. 2019. Identification of genetic diversity among isolates of Sorghum mosaic virus from Louisiana sugarcane [abstract]. Journal American Society of Sugar Cane Technologists. 39:25.
Technical Abstract: An annual survey of plants exhibiting mosaic symptoms is conducted throughout the Louisiana sugarcane industry. Because most commercially grown sugarcane cultivars are resistant or moderately resistant to viruses that cause mosaic, most virus isolates are found among clones in the breeding trials. Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV) cause mosaic of sugarcane, however, SCMV has been rarely found infecting sugarcane in Louisiana for over 70 years. Prior to the 2000s, strains of SCMV and SrMV were identified by symptoms expressed in a set of host plant differentials. Since 2002 a reverse transcriptase-polymerase chain reaction (RT-PCR) protocol has been used to distinguish between SCMV and SrMV and a restriction fragment length polymorphism (RFLP) analysis of the RT-PCR product to identify the strains of the SCMV or SrMV characterized by host differentials. However, the RFLP banding patterns of an increasing number of SrMV isolates collected annually in Louisiana do not match the patterns of recognized strains of SrMV. Among 54 SrMV isolates collected between 2012 and 2018 from 31 released and near-released sugarcane cultivars, those with similar RFLP banding patterns were grouped together. Five groups were identified and a phylogenetic analysis of the nucleic acid sequence of the RT-PCR product revealed similar genetic diversity among the SrMV isolates from Louisiana. An inoculated field experiment has been established to determine pathogenicity of isolates representing the genetic diversity among the SrMV isolates across sugarcane cultivars with different levels of mosaic resistance.