Transgenic orchardgrass (Dactylis glomerata) plants by direct embryogenesis from microprojecticle bombarded leaf cells

Young leaf tissue of orchardgrass (Dactylis glomerata L.) was placed on Schenk and Hildebrandt medium containing 30 µM dicamba. Microprojectiles coated with DNA containing the selectable bar gene (Basta® tolerance) and the reporter gene uidA coding for β-glucuronidase (GUS), both driven by the maize ubiquitin promoter (Ubi1), were propelled into the tissue with a particle inflow gun. Transient GUS expression was observed as blue spots of various sizes on leaf segments. Somatic embryos staining entirely blue were also produced, and embryos germinated on medium containing 3.0 mg 1^–1 bialaphos. Leaves of 67 putative transformed plants were painted with 0.1% Basta. Ten showed no reaction, and 6 showed only a localized response. Cultured leaf segments from tolerant plants also produced somatic embryos that expressed GUS. The genetic transformation was confirmed by Southern blot hybridization and PCR analyses of T₀ plants and by PCR analyses of somatic embryos produced from T₀ plants.