An efficient wheat transformation procedure: transformed calli with long-term morphogenic potential for plant regeneration

A method for producing large numbers of transgenic wheat plants has been de veloped. With this approach, an average of 9.7% of immature embryo explants were transformed and generated multiple self-fertile, independently transf ormed plants. No untransformed plants, or escapes, were regenerated. This t ransformation procedure uses morphogenic calli derived from scutellum tissu e of immature embryos of Triticum aestivum cv. Bobwhite co-bombarded with s eparate plasmids carrying a selectable marker gene (bar) and a gene of inte rest, respectively. Transformed wheat calli with a vigorous growth phenotyp e were obtained by extended culture on media containing 5.0 mg/l bialaphos. These calli retained morphogenic potential and were competent for plant re generation for as long as 11 months. The bar gene and the gene of interest were co-expressed in T0 progeny plants. This wheat transformation protocol may facilitate quantitative production of multiple transgenic plants and si gnificantly reduce the cost and labor otherwise required for screening out untransformed escapes.