STABLE TRANSFORMATION OF SUNFLOWER USING AGROBACTERIUM AND SPLIT EMBRYONIC AXIS EXPLANTS

Stable sunflower transformation has been achieved using Agrobacterium tumefaciens strain EHA101 carrying the binary plasmid PHP158 and split embryonic axis explants of sunflower genotype SMF3. PHP158 contained a plant expressible NPTII gene controlled by a double CaMV 35S promoter and the nopaline synthase 3' region. Chimeric, NPTII-positive transformants were obtained following explant culture in the presence of kanamycin, Seed, associated with the NPTII-positive regions of inflorescences, yielded normal, non-chimeric transformed progeny plants, Southern hybridization analysis detected the presence of integrated T-DNA in T-1, T-2 and T-3 generations. The NPTII gene segregated as a dominant character at a single genetic locus in one T-2 population, NPTII activity remained detectable in T-3 progeny.