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Etiology

Purification and Properties of Foxtail Mosaic Virus. A. Q. Paulsen, Department of Plant Pathology, Kansas State University, Manhattan, KS 66506; C. L. Niblett, Department of Plant Pathology, Kansas State University, Manhattan, KS 66506. Phytopathology 67:1346-1351. Accepted for publication 23 March 1977. Copyright © 1977 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-67-1346.

Foxtail mosaic virus (FMV) infected 56 grass and 35 dicotyledonous species. Development of systemic symptoms first on maturing leaves rather than on emerging leaves was unique and characteristic. Foxtail mosaic virus was seedborne in Briza maxima (2%) and Clintland oats (1%). Myzus persicae and Nephotettix impicticeps were not vectors. Crude sap dilution endpoint was 10^–6, thermal inactivitation point 70 C, longevity in vitro was 46 days in undiluted sap and 105 days in buffered extract. Foxtail mosaic virus was purified from Reno barley by chloroform-butanol clarification and differential centrifugation. Igepon-T-73 and sucrose added to the phosphate buffer for extraction and resuspension reduced aggregation. Purified FMV had an A_260/280 ratio of 1.2 and was very stable at 4 C. Two components sedimenting at 122S and 144S were detected. Extracted nucleic acid sedimented at 32S and its infectivity was eliminated by RNase treatment. Leaf-dip and purified preparations contained rod-shaped particles averaging 430 × 15 nm. Serological tests showed no relationship between FMV and barley stripe (BSMV), brome mosaic (BMV), clover yellow mosaic, panicum mosaic, papaya mosaic, potato X, or tobacco mosaic viruses. Cross-protection tests showed no relationship between FMV and BSMV or BMV.