1Department of Plant Breeding, Cornell University, Bradfield Hall, Ithaca, NY 14853 U.S.A.; 2Department of Genetics and Plant Breeding, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel; 3Department of Plant Pathology, North Carolina State University, Raleigh 27695 U.S.A.; 4Department of Virology, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
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Accepted 15 February 2000.
The Tsw gene conferring dominant resistance to the Tospo-virus Tomato spotted wilt virus (TSWV) in Capsicum spp. has been tagged with a random amplified polymorphic DNA marker and mapped to the distal portion of chromosome 10. No mapped homologues of Sw-5, a phenotypically similar dominant TSWV resistance gene in tomato, map to this region in C. annuum, although a number of Sw-5 homologues are found at corresponding positions in pepper and tomato. The relationship between Tsw and Sw-5 was also examined through genetic studies of TSWV. The capacity of TSWV-A to overcome the Tsw gene in pepper and the Sw-5 gene in tomato maps to different TSWV genome segments. Therefore, despite phenotypic and genetic similarities of resistance in tomato and pepper, we infer that distinct viral gene products control the outcome of infection in plants carrying Sw-5 and Tsw, and that these loci do not appear to share a recent common evolutionary ancestor.
comparative genetic mapping,
viral genome reassortment.
© 2000 The American Phytopathological Society