Abstract

In vitro plant regeneration was achieved from embryogenic cell suspension culture of Astragalus chrysochlorus. When 30-day-old aseptically grown seedlings were cultured on Murashige and Skoog (MS) medium containing 0.1 mg/l α-naphthaleneacetic acid (NAA) plus 1.0 mg/l 6-benzyladenine (BA), friable callus was formed within two weeks from the mesocotyl of the seedling. After three weeks, proliferated actively growing calli were transferred to MS liquid medium containing 2,4-dichlorophenoxyacetic acid (2,4-D), indole-3-acetic acid (IAA) or NAA and subcultured at two week intervals. After two weeks, induction of somatic embryos up to the torpedo stage occured at all tested concentrations of 2,4-D, IAA or NAA. Somatic embryos developed only in MS medium containing 0.5 mg/l IAA within two weeks and 2% of globular embryos were developed into the cotyledonary stage embryos. Eighty one percent of somatic embryos cultured in MS medium supplemented with 0.5 mg/l IAA were found to be diploid by flow cytometric analysis. Plantlet propagation was achieved on half strength MS liquid medium supplemented with 3% (w/v) sucrose after four weeks of culture. After a month on half strength MS medium [1.5% (w/v) sucrose and 0.8% (w/v) agar] 29 of 71 shoots developed into rooted plantlets.

Key words: Somatic embryogenesis, propagation, indole-3-acetic acid, flow cytometry.