Digoxigenin-Labeled cRNA Probes for the Detection of Two Potyviruses Infecting Peanut (Arachis hypogaea). RALF G. DIETZGEN, Queensland Department of Primary Industries, Agricultural Biotechnology Centre, Gehrmann Laboratories, University of Queensland, 4072, Australia. XU ZEYONG, and PIERRE-YVES TEYCHENEY, Queensland Department of Primary Industries, Agricultural Biotechnology Centre, Gehrmann Laboratories, University of Queensland, 4072, Australia. Plant Dis. 78:708-711. Accepted for publication 4 March 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0708.

Nonradioactive dot blot hybridization and chemiluminescent detection were used for the diagnosis of peanut mottle (PeMoV) and peanut stripe (PStV) potyviruses. Digoxigenin-labeled cRNA probes corresponding to the 3' terminal 1,400 (PeMoV) and 1,700 (PStV) nucleotides were transcribed from recombinant cDNA clones. Both viruses were detected in the picogram range in purified preparations and in infected peanut leaf extracts. No cross-hybridization between PStV and PeMoV was observed with either probe under conditions of high stringency. PStV cRNA probes of the complete coat protein gene and 3' untranslated region cross-hybridized with bean common mosaic virus, confirming the close relationship of these two viruses. However, a 300-nucleotide probe corresponding to the variable amino terminus of the coat protein was specific for PStV