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Etiology

Characterization of Dogwood Mosaic Nepovirus from Cornus florida. O. W. Barnett, Department of Plant Pathology and Physiology, Clemson University, Clemson, SC 29634; B. B. Reddick(2), P. M. Burrows(3), and L. W. Baxter, Jr.(4). (2)(4)Department of Plant Pathology and Physiology, Clemson University, Clemson, SC 29634, (2)Present address: Department of Entomology and Plant Pathology, University of Tennessee, Knoxville 37901; (3)Department of Experimental Statistics, Clemson University, Clemson, SC 29634. Phytopathology 79:951-958. Accepted for publication 10 February 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/Phyto-79-951.

A virus serologically related to Arabis mosaic virus was isolated from dogwood (Cornus florida) growing wild in South Carolina in two areas about 0.4 km apart. The virus infected plants in 10 families but caused only mild symptoms on some diagnostic hosts. The particles had a diameter of 27 nm, and purified preparations sedimented as three components in sucrose density gradients. Density gradient electrophoresis of freshly purified virus produced only one band, whereas virus treated with ethylene-diaminetetraacetic acid or stored virus had two bands with electrophoretic mobilities of 5.57 and 6.17 cm^{2<\sup>sec–1V–1. Negative stain penetrated the slower band but not the faster band. Coat protein was predominantly in one band with an estimated molecular mass of 54,100 daltons. After electrophoresis in denaturing gels, RNA separated into two bands: an RNA 1 of 2.9 × 106 daltons and an RNA 2 of 1.4 × 106 daltons. The virus reacted with antisera to four Arabis mosaic virus strains in gel double-diffusion tests and formed spurs with three strains of Arabis mosaic virus and with grape fanleaf virus. Based on epitope similarity indices, this virus was different from Arabis mosaic virus; therefore it was designated dogwood mosaic virus, a new member of the Arabis mosaic virus subgroup of the nepoviruses.}