Cytokinin-induced somatic embryogenesis and plant regeneration in Corydalis yanhusuo (Fumariaceae) - a medicinal plant.

An efficient method has been developed for regeneration of complete plants via somatic embryogenesis in Corydalis yanhusuo (Fumariaceae), an important medicinal plant, using tuber-derived callus. Primary callus was induced by culturing mature tuber pieces on Murashige and Skoog's (MS) medium supplemented with 2.0 mg l(-1) N(6)-benzyladenine (BA) and 0.5 mg l(-1) alpha-naphthaleneacetic acid (NAA) in darkness. Somatic embryos were induced by subculturing the primary callus on MS medium supplemented with 0.5-4.0 mg l(-1) BA, kinetin, or zeatin, within 2 weeks of culture in light. Embryos with well-developed cotyledonary leaves were transferred in half-strength liquid MS medium supplemented with 1.0 mg l(-1) zeatin riboside for the development of roots. Converted somatic embryos were cultured on half-strength MS medium supplemented with 6% sucrose, and with 0.5-10.0 mg l(-1) abscisic acid (ABA), paclobutrazol, or ancymidol, 0.5-5.0 mg l(-1) GA(3) and 15-100 mg l(-1) polyethylene glycol (PEG) 4000 for further development of plantlets and in vitro tuber formation. The development of somatic embryos over the surface of tuber and/or cotyledonary leaf base region of the converted primary somatic embryo was observed. Before ex vitro establishment of somatic embryo-derived plants, plants with well-developed tubers were cultured on half-strength MS medium with 2% sucrose and 0.1 mg l(-1) GA(3) for 3 weeks.