Development of Transgenic Tomato Expressing a High Level of Resistance to Cucumber Mosaic Virus Strains of Subgroups I and II. B. XUE, Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva 14456. C. GONSALVES, and R. PROVVIDENTI, Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva 14456; J. L. SLIGHTOM, Molecular Biology Unit 7242, The Upjohn Company, 301 Henrietta Street, Kalamazoo, MI 49007; M. FUCHS and D. GONSALVES, Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva 14456. Plant Dis. 78:1038-1041. Accepted for publication 15 August 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-1038.

Agrobacterium-mediated transformation was employed to develop transgenic tomato (Lycopersicon esculentum) of line G-S0 that contains the coat protein gene of cucumber mosaic virus white leaf (CMV-WL) strain, a member of Cucumovirus subgroup II. Twenty-nine independently transformed G-80 plants were obtained. R0 transgenic plants accumulated detectable levels of CMV-WL coat protein, and 16 of the 19 inoculated plants were resistant to the CMV China strain, a member of subgroup I. Progenies from three R0 transgenic plants were tested for resistance to infection by CMV-WL and CMV-China. These R1 plants showed high levels of resistance to systemic infection by both strains, as virus could not be recovered from asymptomatic inoculated plants. The development of transgenic tomatoes that are resistant to isolates from both subgroups of CMV should have practical significance for controlling this serious disease, especially since natural sources of CMV resistance have not been identified.