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Etiology

Serological Properties of Oat Necrotic Mottle Virus. C. C. Gill, Research Scientist, Agriculture Canada Research Station, 25 Dafoe Rd., Winnipeg, Manitoba R3T 2M9; Phytopathology 66:415-418. Accepted for publication 24 October 1975. DOI: 10.1094/Phyto-66-415.

Antiserum prepared with a total of 4.9 mg of oat necrotic mottle virus (ONMV) had a titer in microprecipitin tests of 1/4, 096 with 1 mg virus/ml. About 0.12 µg of virus could be detected after absorption of the antiserum with healthy sap and reconcentration of the absorbed antiserum with polyethylene glycol to a titer of 1/4,096. Optimal reacting proportions were 0.5 mg virus/ml and 1:64 dilution of reconcentrated, absorbed antiserum. After clarification of the sap with silver nitrate, oat necrotic mottle virus in sap from oat leaves was readily detectable with the microprecipitin test. In Ouchterlony double-diffusion tests, no immunodiffusion lines were obtained with reconcentrated, absorbed antiserum and ONMV. A broad band near the antiserum well was usually visible with unabsorbed antiserum and purified virus in high-pH ammonia agar gel plates and in 1% agar plates when SDS-ammonium carbonate reagent was added to the virus preparation. The microprecipitin method was the most reliable test for detecting OBMV in partly purified preparations. Antiserum to wheat streak mosaic virus had a titer of 1/8 to ONMV. The ultraviolet absorption spectrum of the virus was maximum at 259 nm and minimum at 247 nm and the average 280:260 and max:min absorption ratios were 0.75 and 1.06, respectively.