Hormone-Induced Indirect Regeneration Protocol for Scutellaria baicalensis Georgi (Huang-qin)

Abstract

There is no report available to date on somatic embryogenesis or even callus formation and plant regeneration in Scutellaria baiclensis (Huang qin). Ours is the first report on somatic embryo development in Scutellaria baicalensis. Plant growth regulators Thidiazuron [TDZ: N-phenyl N'- (1,2,3-thidiazol-5-ylurea)], 6-benzyladenine (BA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were tested alone or in combination for their capacity to induce indirect somatic embryogenesis from leaf, internode, nodal portion, and root explants of Scutellaria baicalensis. The TDZ (4 mg/l) showed the highest percentage of calli-induction frequency in various explants, viz., leaf (42.2%), nodal stem portion (62.9%), and root (63.4%). The TDZ-derived calli were incubated on MS salt + B5 vitamin medium containing glutamine (1.5mM) (MSE) and fortified with various combinations of TDZ, BA, and 2,4-D for induction of somatic embryos. No somatic embryogenesis was recorded in any culture at this stage. On transferring the above friable calli onto hormone-free MSB medium and after 12 days of culture, several globular and heart-shaped embryos appeared over the surface of green compact callus. The mature somatic embryos were dissected out and cultured on hormone-free MS medium for germination. Plantlets were hardened in a growth chamber and, after 30 days, transferred to greenhouse and subsequently to pots and field. There was no morphological difference in plantlets regenerated by this procedure and normal seed-grown plant.