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 disarm ed Agrobacterium tumefaciens strain EHA105 bearing a binary vector carrying nptII and uidA genes. Apical shoot bud development and organogenesis induc ed on the explants led T-0 transgenic plants. Southern blot analysis reveal ed complex integration patterns in T-0 plants. The uidA gene segregated as a dominant trait and single-insertion events were observed in T-1 plants. P atterns similar to those of T-1 plants were observed in T-2 progeny.