In order to evaluate the effect of inoculation and co-cultivation media elements on transformation frequency in Petunia hybrida,modified MS media with different elements were tested on Alvan and Large Flower Alvan (LF Alvan), two local cultivars. Leaf explants of both cultivars were inoculated withAgrobacterium tumefaciens strain LBA4404 (pBI121) containing neomycin phosphotransferase (nptII) and an intron-containing b-glucuronidase (gus) genes. When medium lacking KH2PO4, NH4NO3, KNO3, and CaCl2 was used as inoculation and co-cultivation medium, a higher frequency of transformation for Alvan (22%) and LF Alvan (16%) was obtained. Kanamycin resistant plantlets were stained blue by GUS assay. Furthermore, polymerase chain reaction (PCR) analysis revealed the presence of bothgusandnptIIgenes in all putative transformants. Finally, southern blot hybridization confirmed insertion of 1–4 copies ofgusgene in transgenic plants.
