Establishment of the System of Conventional Maize Inbred-lines Tranformation Mediated by Agrobacterium tumefaciens

Elite inbred-lines of maize, 340 and 4112, which were widely used in hybridization were transformed with Agrobacterium tumefaciens. The immature embryos and their initial callus were infected by A. tumefaciens LBA4404 (pGBIL04).Selected on the medium containing phosphinothricin (PPT), the resistant calli were differentiated to plants. It was proved that the target Bt gene had been integrated into the genome of regeneration plants after PCR analysis and transformation frequency was 1.68%～4.44%. The factors influencing maize transformation by A. tumefaciens were studied. The results showed that the frequency of selection was highest when OD600 of engineering bacterial suspension was 0.5. Pre-culture was favorable to immature embryos' transformation.It was feasible that the immature embryos had been induced to form initial callus. The frequency of selection and PCR+via A. tumefaciens increased along with lowering the co-culture temperature to 22℃.