Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 20, 2002
Publication Date: June 20, 2002
Citation: Grisham, M.P., Pan, Y. 2002. A Shift in the Strains of Sorghum Mosaic Virus Causing Mosaic in Louisiana Sugarcane [abstract]. Phytopathology. 92(6):532. Technical Abstract: Mosaic of sugarcane is caused by strains of sugarcane mosaic virus (SCMV) or sorghum mosaic virus (SrMV). During the first half of the Twentieth Century, mosaic in Louisiana sugarcane was caused by strains of SCMV. SrMV strains H, I, and M were identified in 1956, 1966, and 1973, respectively. In field surveys of plants with mosaic symptoms conducted between 1978 and 1995, more than 90% were infected with SrMV strain H, the remainder with strains I and M. No plant was found infected with SCMV. Surveys were discontinued because of the large amount of labor required to identify strains using host differentials and the results had changed little in 10 years. A survey conducted in 2001 using an reverse transcriptase-polymerase chain reaction-based restriction fragment length polymorphism (RFLP) analysis to identify SCMV and SrMV strains indicated a shift in the population of strains. SrMV strain I and strain H were associated with approximately 65% and 21% of the sugarcane plants with mosaic symptoms, respectively. The remainder of the plants (14%) with mosaic symptoms appeared to be infected by a new strain with a distinctive RFLP banding pattern. Nucleotide sequencing is being conducted to identify the virus strain.