Effect of Tobacco Etch and Tobacco Vein Mottling Virus on Yield of Burley Tobacco Genotypes. Rebeca C. Rufty, Assistant Professor of Crop Science and Plant Pathology, North Carolina State University, Raleigh 27695. R. D. Miller, and G. V. Gooding, Jr., Associate Professor of Plant and Soil Science, University of Tennessee, Knoxville 37901; and Professor of Plant Pathology, North Carolina State University, Raleigh 27695. Plant Dis. 73:45-48. Accepted for publication 8 August 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0045.

Burley tobacco (Nicotiana tabacum L.) cultivars and experimental breeding lines were evaluated for yield response in the presence of tobacco etch (TEV) and tobacco vein mottling (TVMV) viruses under field conditions for 2 years at two locations. Breeding lines Greeneville 131 (from Tennessee) and MDH 5, MDH 19, MDH 25, and MDH 28 (from North Carolina) were found to be highly resistant to TEV and TVMV. These breeding lines exhibited little or no virus symptoms and their resistance is conditioned by a single recessive factor derived from Virgin A Mutant. Cultivars Kentucky 14 and Kentucky 10 exhibited high yields despite presence of virus symptoms. High-yielding cultivars R7-11, Kentucky 14 × L8, and Burley 21 × Kentucky 10 had only moderate yields in the presence of either virus. Cultivars Burley 37 and Burley 49 were extremely susceptible, based on very low yields and severe virus symptoms. Cultivars Havana 307 and Sota 6505 were found to possess a new source of TEV and TVMV resistance. It may be possible to combine different sources of resistance along with tolerance in a single genotype.