Submitted to: Sugar Journal
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2002
Publication Date: 6/20/2002
Citation: Grisham, M.P., Pan, Y. 2002. Molecular identification of virus isolates causing mosaic in Louisiana sugarcane. Sugar Journal. 65(1):26-27. Interpretive Summary:
Technical Abstract: Ten strains of sugarcane mosaic virus (SCMV) and three strains sorghum mosaic virus (SrMV) have been reported to cause mosaic in Louisiana; however, only strains H, I, and M of SrMV were recovered from commercial fields during surveys conducted between 1973 and 1995. Annual surveys were discontinued because of the large amount of labor required to identify strains using host differentials. At the time of these surveys, this was the only technique available to identify strains of these viruses, and results had changed little during the last 10 years of the surveys. Recent advances in technology have led to the development of a laboratory procedure capable of distinguishing the mosaic virus strains. A survey was conducted in 2001 using reverse transcriptase-polymerase chain reaction-based restriction fragment length polymorphism (RT-PCR RFLP) analysis to determine if changes have occurred among the strains of virus causing mosaic of sugarcane in Louisiana. Strain I and strain H of SrMV were associated with approximately 65% and 21% of the sugarcane plants with mosaic symptoms, respectively. In the earlier surveys, more than 80% of the plants were infected with strain H each year. The remainder of the plants (14%) surveyed in 2002 appeared to be infected by a new strain with a distinctive RFLP banding pattern. Nucleotide sequencing is being conducted to identify the virus strain. Sugarcane plants with mosaic symptoms will be collected in 2002 from a wider geographical area of the state and virus strains infecting the plants will be determined by RT-PCR-RFLP analysis.