Agrobacterium-Mediated Transformation of Walnut Somatic Embryos and Regeneration of Transgenic Plants

Genetically transformed walnut plants were regenerated from somatic embryos inoculated with a disarmed Agrobacterium tumefaciens strain containing a gene encoding kanamycin resistance. Embryo subclones derived from the inoculated embryos were selected for continued embryo proliferation on kanamycin-containing medium. Embryos and shoots were shown to contain and express the foreign gene and have been subjected to rooting procedures. Four rooted plantlets have been transplanted to soil and acclimatized. This is the first report of the successful transformation of a woody tree species from somatic embryos using Agrobacterium.