In vitro propagation of Psoralea corylifolia L. by somatic embryogenesis in cell suspension culture

An effective protocol was developed for in vitro propagation of Psoralea corylifolia via somatic embryogenesis in cell suspension culture. Embryogenic callus was obtained on Murashige and Skoog (MS) medium supplemented with 6 mu M naphthaleneacetic acid (NAA) and 30 mu M glutamine from transverse TCLs from 10-day-old hypocotyl explants with a 96.4% frequency. Embryogenic callus produced a higher number of somatic embryos (123.7 +/- A 1.24 per gram fresh weight callus) on MS medium containing 30 g l(-1) sucrose, 1 mu M NAA, 4 mu M benzyladenine (BA), 15 mu M glutamine and 2 mu M abscisic acid (ABA) after 4 weeks of culture. Somatic embryos successfully germinated (97.6%) on A1/2 MS medium containing 20 g l(-1) sucrose, 8 g l(-1) agar and supplemented with 2 mu M BA, 1 mu M ABA and 2 mu M gibberellic acid (GA(3)) within 2 weeks of culture. Somatic embryos developed into normal plants, which hardened with 100% efficiency in soil in a growth chamber. Plants were successfully transferred to greenhouse and subsequently established in the field. Plant survival percentage in the field differed with seasonal variations. Average psoralen content of 12.9 mu g g(-1) DW was measured in different stages of somatic embryo development by high-performance liquid chromatography (HPLC). This protocol will be helpful for efficient propagation of elite clones on a mass scale, conservation efforts of this species and for secondary metabolites production studies.