IDENTIFICATION OF VIRUS ISOLATES CAUSING MOSAIC OF SUGARCANE IN LOUSIANA

Authors: Grisham, Michael; Pan, Yong-Bao

Submitted to: International Congress of Plant Pathology Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 8/20/2003
Publication Date: 2/20/2003
Citation: Grisham, M.P., Pan, Y. 2003. Identification of virus isolates causing mosaic of sugarcane in Lousiana [abstract]. 8th International Congress on Plant Pathology, February 2-7, 2003, Christchurch, New Zealand. 2(23.31):308.

Interpretive Summary:

Technical Abstract: Ten strains of sugarcane mosaic virus (SCMV) and three strains of sorghum mosaic virus (SrMV) have been shown to cause sugarcane mosaic in Louisiana, USA; however, surveys conducted between the 1970s and 1995 identified strains of SrMV only. In 2001 and 2002, approximately 350 leaf samples from plants showing mosaic symptoms were collected from 10 locations throughout the Louisiana sugarcane industry. Virus isolates associated with the diseased plants were identified using reverse transcriptase-polymerase chain reaction (RT-PCR) to distinguish between SCMV and SrMV and a restriction fragment length polymorphism (RFLP) analysis of the RT-PCR product to identify strains within each virus. SrMV strains I and H were associated with approximately 65% and 21% of the sugarcane plants with mosaic symptoms, respectively. In surveys conducted between 1990 and 1995, over 90% of the samples were infected with strain H. No SCMV strain was associated with the diseased plants. RT-PCR showed that approximately 8% of the samples were infected with SrMV, but the RFLP banding pattern did not match any known strain. Nucleotide sequencing and pathogenicity tests are being conducted to determine if new strains of SrMV are responsible for causing these infections. No RT-PCR product was produced by either the SCMV or the SrMV primer set for approximately 6% of the plants showing mosaic symptoms suggesting that another virus may cause mosaic in sugarcane.