Somatic embryogenesis and plant regeneration in leaf and petiole explant cultures and cell suspension cultures of Pinellia tripartita

Culture conditions for high frequency plant regeneration via somatic embryogenesis and from cell suspension cultures of Pinellia tripartita are described. Leaf and petiole explants formed embryogenic cultures at frequencies of 36.8% and 26.7%, respectively, on Murashige and Skoog (MS) medium supplemented with 1.33 muM 6-benzyladenine (BA) and 10.74 muM alpha-naphthaleneacetic acid (NAA). However, leaf and petiole explants did not form embryogenic cultures on MS medium with various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) as the sole growth regulator. Leaf-derived embryogenic cultures were transferred to MS medium with 4.52 muM 2,4-D and were subcultured at 4-week intervals. Cell suspensions were established from subcultured embryogenic cultures using liquid MS medium with 4.52 muM 2,4-D. Upon plating onto MS basal medium, greater than or equal to70% of cell aggregates gave rise to somatic embryos and later plantlets. Regenerated plantlets were transplanted to potting soil and developed to maturity at a frequency of greater than or equal to90% in a growth chamber.