Genetic transformation of the American cranberry, Vaccinium macrocarpon Ait., was accomplished using electric discharge particle acceleration. Plasmid DNA containing the genes GUS (β-glucuronidase), NPTII (neomycin phosphotransferase II), and BT (Bacillus thuringiensis subsp. kurstaki crystal protein) was introduced into stem sections, derived from in vitro cultures, that had been induced to form adventitious buds. The stage of development of these adventitious buds was critical for efficient initial expression. After exposure to electric discharge particle acceleration, stem sections were cultured on a solid-phase bud-inducing medium containing 300 mg kanamycin/liter. In addition, a thin overlay of 300 mg kanamycin/liter in water was added to inhibit growth of nontransformed cells. Within 7 weeks, green shoots emerged amidst kanamycin-inhibited tissue. No escape (nontransformed) shoots were recovered, and 90% of the transformed shoots were shown through PCR and Southern blot analysis to contain all three introduced genes. GUS expression varied markedly among various transformed plants. Preliminary bioassays for efficacy of the BT gene against the feeding of an economically important lepidopteran cranberry pest have shown no consistently effective control. Potential problems with the expression of the BT and GUS genes are discussed
Rodney Serres, Elden Stang, Dennis McCabe, David Russell, Daniel Mahr, and Brent McCown
Rod Serres, David Russell, Dan Mahr, and Brent McCown
Genetically transformed Vaccinium macrocarpon `Stevens' and `Pilgrim' plants have been obtained using electric discharge particle acceleration. Three foreign genes, kan encoding a selectable marker, gus a reporter gene, and B.t.k. conferring lepidopteran resistance, were incorporated into the genome. Expression of kan was assayed by culturing shoots in vitro on media with several concentrations of kanamycin. Expression among transformed clones (transclones) varied from high resistance (normal growth at 300 mg/L kan) to no resistance. Histochemical analyses for gus expression revealed variability among transclones. Some transclones exhibited no gus expression, others had consistent area-specific expression while others displayed random expression. In preliminary feeding trials with blackheaded fireworm larvae, B.t.k. expression was found to be ineffective at controlling insect development. We have recovered plants transformed with a different promoter driving the B.t.k. gene in an effort to enhance expression.
R. Karina Gallardo, Parichat Klingthong, Qi Zhang, James Polashock, Amaya Atucha, Juan Zalapa, Cesar Rodriguez-Saona, Nicholi Vorsa, and Massimo Iorizzo
species), phytophthora ( Phytophthora spp.), storage rots (various fungal species), upright dieback ( Phomopsis vaccinii ), and other diseases. The arthropod pest traits included were blackheaded fireworm ( Rhopobota naevana ), blunt-nosed leafhoppers
Justine E. Vanden Heuvel and Martin C. Goffinet
concentrations of cranberry HortTechnology 16 277 285 Cockfield, S.D. Mahr, D.L. 1992 Flooding cranberry beds to control blackheaded fireworm (Lepidoptera: Tortricidae) J. Econ. Entomol. 85 2383 2388