ToMV-Resistant transgenic tomato as a material for the first field experiment of genetically engineered plants in Japan

Summary An F₁ hybrid betweenLycopersicon esculentum andL. peruvianum was transformed using a Ti-plasmid binary vector with a coat protein gene cDNA of an attenuated tomato mosaic virus (ToMV) strain L₁₁A which was expressible by the 35S promoter of cauliflower mosaic virus (CaMV). A transgenic plant which expressed the most resistance to ToMV was chosen as a material to be tested in a nonisolated greenhouse and in the field. This transgenic tomato plant was propagated by cutting. In the first test using an isolated greenhouse and in the second test conducted in an nonisolated greenhouse, no major morphologic and physiologic differences were found between the transgenic plants and the nontransgenic control plants. Also, there was no evidence that the transgenic plants produced any new hazardous substances. Both the transgenic and the nontransgenic plants were self-sterile, and crossing of the cultivated species with pollen of these plants produced few seeds. These features of the transgenic plants satisfied the requirements for a small scale field test. The field test of the transgenic plants are in progress. Presented in the Session-in-Depth “Field Test Requirements and Performance of Transgenic Plants” at the 1991 World Congress on Cell and Tissue Culture, Anaheim, California, June 16–20, 1991.