Genetic transformation of Iris germanica mediated by Agrobacterium tumefaciens

A protocol was developed for production of transgenic iris plants (Iris ger manica L. 'Skating party') from regenerable suspension cultures via Agrobac terium-mediated transformation. We tested a series of selection agents, and identified hygromycin and geneticin as the most suitable for selecting tra nsformed iris cells. Suspension cultures of iris were cocultured for 3 days with A. tumefaciens LBA 4404(pTOK233) carrying an intron-interrupted uidA (GUS) gene encoding beta-glucuronidase, and hpt (hygromycin) and nptII (gen eticin) selectable marker genes. Hygromycin- or geneticin-resistant calli h aving GUS enzyme activity were identified and used to induce plant regenera tion. More than 300 morphologically normal transgenic iris plants were obta ined in approximate to 6 months. About 80 % of the transformants were GUS-p ositive and NPTII-positive (paromomycin-resistant). Integration of transgen es into the nuclear genome of iris plants,vas confirmed by Southern blot an alysis. We have, therefore, developed an efficient A. tumefaciens-mediated transformation system for Iris germanica, which,will allow future improveme nt of this horticulturally important ornamental monocot via genetic enginee ring.