Fertile transgenic maize plants with foreign gene as well as method for their production

摘要

Starting from immature embryos on hormone-free nutrient media there is formation, at the stem base of the germ plant, of an auxin-autotrophic, embryogenic callus which retains its embryogenesis ability on subcultivation on hormone-free medium over a lengthy period. Besides fully developed embryos, also produced under suitable culture conditions (6-9% sucrose in the medium) are adventitious embryos. When the sucrose content is reduced to 2-3% and 2,4-dichlorophenoxyacetic acid is added there is formation of soft, granular calli which consist of embryogenic cell aggregates (type II callus). It is possible to isolate totipotent protoplasts after subcultivation of the type II callus as cell suspension culture. The maize plants according to the invention are regenerated from these protoplasts.