Detection of Sugarcane Mosaic Virus and Fiji Disease Virus in Diseased Sugarcane using the Polymerase Chain Reaction. GRANT R. SMITH, Research Officer, David North Plant Research Centre, Bureau of Sugar Experiment Stations, P.O. Box 86, Indooroopilly, Q4068, Australia. RUTH VAN DE VELDE, Research Associate, David North Plant Research Centre, Bureau of Sugar Experiment Stations, P.O. Box 86, Indooroopilly, Q4068, Australia. Plant Dis. 78:557-561. Accepted lor publication 17 December 199.1. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0557.

The reverse transcription-polymerase chain reaction (RT-PCR) was adapted for detection of sugarcane mosaic potyvirus (SCMV) and Fiji disease fijivirus (FDV) in total nucleic acid extracts [from diseased sugarcane. The denaturation method developed for RT-PCR of FDV-specific double-stranded RNA (dsRNA) was suitable for the amplification of SCMV RNA and also amplified SCMV-specific replicative form (double-stranded) RNA. RT-PCR amplification of total nucleic acid extracts from SCMV-infected sugarcane yielded a 359-bp product and detected the presence of the virus in a 1:104 dilution of a solution containing the total nucleic acids extracted from 250 mg of SCMV-infected tissue. Four primer pairs, selected to prime the synthesis of different regions of the segmented dsRNA genome of FDV, were evaluated; the oligonucleotide pair FDV7F and FDV7R, which prime the synthesis of a 450-bp fragment, gave the best result. FDV was detected in a 1:107 dilution of a solution containing the total nucleic acids extracted from 250 mg of FDV-infected sugarcane tissue. Both viruses could be RT-PCR amplified from the same sample by including both primer pairs in the reaction Solutions (duplex RT-PCR). The viruses were identified in the sample by the difference in [ size of the synthesized products, and the identity was confirmed by Southern blot hybridization with the appropriate probe.

Keyword(s): diagnosis, Saccharum