TRANSGENIC ORCHARDGRASS (DACTYLIS-GLOMERATA) PLANTS BY DIRECT EMBRYOGENESIS FROM MICROPROJECTICLE BOMBARDED LEAF-CELLS

Young leaf tissue of orchardgrass (Dactylis glomerata L.) was placed o n Schenk and Hildebrandt medium containing 30 mu M dicamba. Microproje ctiles coated with DNA containing the selectable bar gene (Basta(R) to lerance) and the reporter gene uidA coding for beta-glucuronidase (GUS ), both driven by the maize ubiquitin promoter (Ubi1), were propelled into the tissue with a particle inflow gun. Transient GUS expression w as observed as blue spots of various sizes on leaf segments. Somatic e mbryos staining entirely blue were also produced, and embryos germinat ed on medium containing 3.0 mg l(-1) bialaphos. Leaves of 67 putative transformed plants were painted with 0.1% Basta. Ten showed no reactio n, 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 a nd PCR analyses of T-0 plants and by PCR analyses of somatic embryos p roduced from T-0 plants.