Biolistic transformation of broccoli (Brassica oleracea var. italica) for transient expression of the beta-glucuronidase gene

We report for the first time conditions for the biolistic transformation of broccoli. Efficient transient expression of the beta-glucuronidase (gus) g ene has been obtained following transformation of broccoli cv. Marathon F1 (Brassica oleracea var. italica) cotyledons via microparticle bombardment. The influence of several particle gun delivery parameters and pre-treatment of cotyledon leaf discs on rates of transient GUS expression have been inv estigated. Consistently high rates of transformation were obtained using M1 7 tungsten particles fired at 900 psi with a gap distance of 20 mm and a ta rget distance of 55 mm. Bombardment of cotyledon leaf discs placed on callu s induction media doubled rates of transient transformation events. Pre-cul turing cotyledon leaf discs on either hormone-free media or callus inductio n media resulted in a decrease in transient transformation events.