Production of transgenic plants of the Liliaceous ornamental plant Agapanthus praecox ssp orientalis (Leighton) Leighton via Agrobacterium-mediated transformation of embryogenic calli

A system for producing transgenic plants was developed for the Liliaceous ornamental Agapanthus praecox ssp. orientalis (Leighton) Leighton via Agrobacterium-mediated genetic transformation. Leaf-derived embryogenic calli were inoculated with A. tumefaciens strain EHA101/pIG121Hm or LBA4404/pTOK233, both of which harbored the binary vector carrying the neomycin phosphotransferase II(NPTII), hygromycin phosphotransferase (HPT) and intron-containing beta -glucuronidase (GUS-intron) genes in the T-DNA region. Following co-cultivation, the calli were transferred to a medium containing 1 mg 1(-1) picloram (PIC), 50 mg 1-1 hygromycin and 500 mg 1(-1) cefotaxime, on which several hygromycin-resistant (Hyg(r)) cell clusters were obtained 5-6 weeks after transfer. Agrobacterium strain, co-cultivation period and acetosyringone (AS) treatment during co-cultivation affected the number of Hyg(r) callus lines produced: the best result was obtained when embryogenic calli were co-cultivated with LBA4404/pTOK233 for 7 days in the presence of 20 mg 1(-1) AS. Hyg(r) calli were transferred to the same medium, but lacking PIG, for inducing somatic embryos. Somatic embryos thus obtained developed into complete plantlets following their transfer to a medium without PIC and antibiotics. All of them were verified to be stable transformants by GUS histochemical assay, PCR and Southern blot analyses. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.