TRANSFORMATION OF ELITE COTTON CULTIVARS VIA PARTICLE BOMBARDMENT OF MERISTEMS

A variety-independent protocol was developed to allow the production of transgenic cotton. High velocity gold beads coated with DNA were used to deliver foreign genes directly into the meristematic tissue of excised embryonic axes. Bombarded explants were allowed to develop into plants which were subsequently screened for gus gene activity. Buds in the axils of transformed leaves were forced to develop into plants by pruning away non-transformed primary shoot tips. Plants derived from this process carried the foreign gene in one or more of their tissue layers. Transformation frequencies varied with the genotype used, but all cultivars attempted to date have yielded transgenic progeny. Molecular and genetic characterization of primary transformants and their progeny established that foreign genes were stably integrated and transmitted to progeny in a Mendelian fashion.