Production of stable transgenic sunflowers (Helianthus annuus L.) from wounded immature embryos by particle bombardment and co-cultivation with Agrobacterium tumefaciens.

Split embryonic axes of 21-day old immature sunflower (Helianthus annuus L.) embryos were bombarded by microparticles and then co-cultured with disarmed Agrobacterium tumefaciens strain EHA105 bearing a binary vector carrying nptII and uidA genes. Apical shoot bud development and organogenesis induced on the explants led T0 transgenic plants. Southern blot analysis revealed complex integration patterns in T0 plants. The uidA gene segregated as a dominant trait and single-insertion events were observed in T1 plants. Patterns similar to those of T1 plants were observed in T2 progeny.