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Resistance

Survey of Susceptibility to Cowpea Mosaic Virus Among Protoplasts and Intact Plants from Vigna sinensis Lines. H. Beier, Postdoctoral Research Associate, Department of Biochemistry and Biophysics, University of California, Davis, CA 95616, Present address: Biologisches Institüt der Universitaet, 7 Stuttgart, West Germany; D. J. Siler(2), M. L. Russell(3), and G. Bruening(4). (2)(3)(4)Graduate Student, Staff Research Associate, and Professor, respectively, Department of Biochemistry and Biophysics, University of California, Davis, CA 95616, (2)Present address: Louis Berger International, East Orange, New Jersey. Phytopathology 67:917-921. Accepted for publication 3 January 1977. Copyright © 1977 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-67-917.

One thousand thirty-one lines of Vigna sinensis (cowpea) were surveyed for response to mechanical inoculation of the SB isolate of the yellow subgroup of cowpea mosaic virus on the primary leaves of seedlings. Sixty-five lines (6.3% of the total) were classified as operationally immune because no symptoms were observed and no virus was recovered at 7 to 12 days after the inoculation with purified virus at a concentration which was one hundred times that which would uniformly infect susceptible lines. Protoplasts were recovered from primary leaves of 55 of the immune lines. Protoplasts from 54 of the immune lines proved to be susceptible to the SB isolate.