TRANSGENIC CEREAL PLANTS

摘要

To obtain a transgenic cereal plant which is stably transformed, an exposed cereal meristem is subjected to biolistic bombardment in order to target non-differentiated meristem cells for transformation. Immature embryos at the early proembryo, mid proembryo, late proembryo, transitional or early coleoptilar stage are harvested for biolistic bombardment. The meristem tissue or cells fated to contribute to the meristem then are manipulated in order to enlarge transgenic sectors, either through selection and/or through effecting a proliferation from the tissue of shoots or multiple meristems per se. The shoot population thus obtained then is screened, by means of a nonlethal enrichment assay, to identify either chimeric sectors that will contribute to germline transmission, or non-sectored, L2 periclinal chimeras that will by definition transmit to progeny. Increased time in culture, under selection, enhances the prospects for sectoral-to-periclinal conversions, and also selects for L1-to-L2 conversions which, through a shift in position, ultimately contribute to the germline. Transgenic sectors also are stabilized during the step of tillering.