TRANSFORMATION OF SUNFLOWER (HELIANTHUS-ANNUUS L) FOLLOWING WOUNDING WITH GLASS-BEADS

A procedure was developed for transformation of Helianthus annuus (sun flower) using Agrobacterium tumefaciens. Cotyledons were removed from young seedlings, and the remaining tissue was uniformly wounded by sha king with glass beads. The wounded tissue was then co-cultivated with hypervirulent strain of Agrobacterium tumefaciens harboring the binary plasmid pCNL56. Minimal use of defined medium was required, and no ca llus was observed. The polymerase chain reaction (PCR) followed by DNA hybridization demonstrated the presence of gusA DNA from pCNL56 in to tal leaf DNA of 6 primary transformants and 2 progeny plants. No Agrob acterium DNA was detected in total DNA from transformed sunflower leav es that was amplified with primers specific to the miaA chromosomal ge ne of Agrobacterium. Foreign DNA was also detected in the next generat ion. beta-Glucuronidase (GUS) activity was demonstrated for 5 of the T -2 transgenic plants. Grafting was used to increase the number of seed s present on plants that had undergone tissue culture manipulations.