Somatic embryogenesis and Agrobacterium-mediated transformation system for scented geraniums (Pelargonium sp. `Frensham')

Plant regeneration via somatic embryogenesis was achieved from leaf petioles of Pelargonium sp. `Frensham' cultured on Murashige and Skoog medium containing 15 μM N6-benzyladenine, and 5 μM α-naphthaleneacetic acid (NAA). More than 80% of these somatic embryos converted into plants when isolated and cultured on Murashige and Skoog medium supplemented with 15 μM NAA. Stable transgenic plants were obtained by co-cultivation of the petioles (prior to culture) with Agrobacterium tumefaciens strains LBA4404 (harbouring a binary vector pBI121 carrying the nptII and gus genes) and LBG66 (harbouring a binary plasmid pJQ418 carrying the gus/int:nptII fusion gene). Transformants were selected using kanamycin and transformation was verified by β-glucuronidase histochemical assay and polymerase chain reaction. Southern analysis further confirmed the integration of these genes into the genome of transgenic plants. We report here for the first time, an Agrobacterium-mediated model transformation system coupled with regeneration via somatic embryogenesis for production of transgenics in Pelargonium sp.