Somatic embryogenesis and plant regeneration in Pterocarpus marsupium Roxb.

Abstract

Somatic embryogenesis (SE) has been achieved from hypocotyl-derived callus culture in Pterocarpus marsupium. Ninety percent of hypocotyl explants (excised from 12-day-old in vitro germinated axenic seedlings) produced callus on Murashige and Skoog medium supplemented with 5μM 2,4-dichlorophenoxyacetic acid and 1μM a 6-benzyladenine (BA). Induction of SE occurred after transfer of callus clumps (200±20mg fresh mass) to MS medium supplemented with BA at 2. 0μM, where a maximum of 23. 0±0. 88 globular stage embryos per callus clump were observed after 4weeks of culture. Subculturing of these embryos on MS medium supplemented with 0. 5μM BA, 0. 1μM α-naphthalene acetic acid and 10μM abscisic acid significantly enhanced the maturation of somatic embryos to early cotyledonary stage, where 21. 4±0. 32 embryos per callus clump were recorded after 4weeks of culture. Of 30-well developed somatic embryos, 16. 6±0. 33 germinated and subsequently converted into plantlets on half-strength MS medium supplemented with 1. 0μM BA. The morphologically normal plantlets with well-developed roots were first transferred to 1/4-liquid MS medium for 48h and then to pots containing autoclaved soilrite and acclimatized in a culture room. Thereafter, they were transferred to a greenhouse, where 60% of them survived. © 2010 Springer-Verlag.