Direct Somatic Embryogenesis from Immature Zygotic Embryos of Flax (Linum usitatissimum L.)

Growth responses have been studied for immature (late heart to early cotyledonary) flax embryos cultured on Monnier's basal medium with or without BAP (0.05 mg · 1−1), yeast extract (1.0 g · 1−1) and glutamine (0.4 g · 1−1). Basal medium alone (± glutamine) gave embryo germination. Yeast extract (± glutamine) gave strong inhibition of the shoot and root apices. BAP (± glutamine) stimulated shoot proliferation and callus formation. Addition of BAP together with yeast extract stimulated direct somatic embryogenesis from the hypocotyl in the presence of glutamine. Without glutamine responses resembled those stimulated by BAP alone. Factors controlling the induction of embryogenesis are discussed.