Transformation of eggplant (Solanum melongena L.) and Chinese kale (Brassica alboglabra Bayley) using Agrobacterium tumefaciens as a vector

The cocultivation of plant tissues with Agrobacterium tumefaciens has been found to be an efficient method to transform plant cells. The use of genetic transformation in plant improvement depends on transformation and regeneration. Eggplant and chinese kale decapitated seedlings cultured in vitro were found to be able to regenerate profusely from the cut end surface. When the decapitated seedlings were cocultivated with A. tumefaciens binary vector strain (LBA4404 containing pBI121) the frequency of transformation was low (0.3%), however if wild type A. tumefaciens strain (C58 and T37) were used, the frequency of transformation was high (over 30%).; The ineffectiveness of binary vectors was not inherent to eggplant but to the method or protocol in use. When A. tumefaciens was cocultivated with cotyledons, a high frequency of transformation was obtained with the disarmed binary vector (20%) as well as the wild type strains (35%).; The problem with the low transformation is not associated with the bacteria chromosomal genes. The addition of vir inducing compounds to the bacteria culture did not increase transformation. Apparently the problem of a low transformation is due to the Ti-plasmid. The presence of the wild type Ti-plasmid of A. tumefaciens Ach5 strain increased the transfer frequency of the T-DNA region from plasmid pBI121 in both decapitated seedling and cotyledon.; The lack of genes involved in phytohormone synthesis in strain LBA4404(pBI121) may be limiting transformation. The addition of exogenous phytohormones to the bacteria culture or plant medium increased transformation in the cotyledon cocultivation method. The transformation of eggplant appeared to occur preferentially in those tissues that formed callus abundantly. Factors that promoted callus formation also increased the frequency of transformation.; The inability of kanamycin to select for putative transformed tissue in decapitated seedlings appears to contribute to the low transformation. It appears that kanamycin must be in contact with the plant tissue for efficient selection and that kanamycin should be added prior to regeneration. Transfer of cotyledons 48 hours after tissue inoculation to selection medium was successful in that there was preferential growth of transformed cells, reducing the task of screening.