Detection of Potato Leafroll and Strawberry Mild Yellow-Edge Luteoviruses by Reverse Transcription-Polymerase Chain Reaction Amplification. A. Hadidi, National Germplasm Resources Laboratory, Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA), Bldg. 011A, Beltsville, MD 20705. M. S. Montasser, L. Levy, R. W. Goth, R. H. Converse, M. A. Madkour, and L. J. Skrzeckowski. National Germplasm Resources Laboratory, Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA), Bldg. 011A, Beltsville, MD 20705; Vegetable Laboratory, ARS, USDA, Beltsville, MD 20705; Horticultural Crops Research Laboratory, ARS, USDA, Corvallis, OR 97331; National Agricultural Genetic Engineering Laboratory, Ministry of Agriculture and Land Reclamation, Giza 12619, Egypt; and Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02532 Warsaw, Poland. Plant Dis. 77:595-601. Accepted for publication 4 February 1993. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1993. DOI: 10.1094/PD-77-0595.

DNA primers were constructed based on the nucleotide sequence of the coat protein gene of potato leafroll luteovirus (PLRV) and utilized for cDNA synthesis and polymerase chain reaction (PCR) amplification of a 487-bp DNA fragment from nucleic acid extracts of PLRV-infected tissue, and an approximately 500-bp DNA fragment from the luteovirus associated with strawberry mild yellow-edge-infected tissue. The amplified DNA fragments were identified by hybridization analysis with a cDNA probe for the coat protein gene of PLRV and differentiated by restriction fragment length polymorphism analysis. Reverse transcription (RT)-PCR assays were developed for the detection of PLRV in nucleic acid extracts of infected potato leaves and tubers, and in viruliferous aphids. The luteovirus-specific DNA was absent from amplified extracts of uninfected potato or nonviruliferous aphids. The RT-PCR assay for PLRV is more sensitive than existing detection methods and detects PLRV in plant hosts or insect vectors without requiring large samples or molecular hybridization.