Regeneration of fertile plants from excised immature zygotic embryos of Arabidopsis thaliana.

We present protocols for the regeneration of fertile plants from immature zygotic embryos of Arabidopsis thaliana ecotype "Zürich" either directly by multiple shoot formation from the apical region or indirectly by shoot induction from embryo derived calli. The regeneration efficiency by "multiple shooting" depended on the developmental stage of the cultured embryos and ranged from 15% for early heart shaped to 90% for early torpedo shaped and further developed embryos. 85% callus induction was achieved from embryos in the early torpedo shaped or a later stage of development. The efficiency of shoot induction from embryo derived calli varied between 25% and 75% in different experiments.