Recurrent somatic embryogenesis and plant regeneration from seedlings of Hepatica nobilis Schreb.

A method for secondary somatic embryogenesis was developed on embryos derived from embryogenic callus formed on Hepatica nobilis seedlings. Somatic embryogenesis (SE) was induced on seedlings (on the hypocotyl and epicotyl parts) grown on the Murashige and Skoog (1962) medium (MS) supplemented with 1 mu M naphthaleneacetic acid (NAA), and/or 0.1 mu M 6-benzyladenine (BA) and on medium without plant growth regulators (PGR). The best response of embryogenic callus formation was observed on the medium containing 1 mu M NAA alone or with 0.1 mu M BA. Individual somatic embryos, formed on embryogenic callus on the medium without PGR (MS0), at heart, torpedo and cotyledonary stage, were transferred to the media where secondary somatic embryo formation and development into plantlets occurred. Although the most efficient repetitive cycles of secondary SE were recorded for all stages of somatic embryos (heart, torpedo, cotyledonary) on the MS0 medium (77.8-87.4 %), secondary somatic embryos were also obtained on all media supplemented with cytokinins. The best rate of somatic embryos germination was achieved on MS media with 0.2 mu M NAA and 2 mu M BA, and 0.1 mu M NAA and 1 mu M BA (48.8-52.0 %) when more mature embryos (cotyledonary stage) were used. Plantlets grown from somatic embryos were successfully acclimatized to greenhouse conditions.