High frequency somatic embryogenesis and plant regeneration in callus cultures of Astragalus adsurgens Pall

Abstract Efficient plant regeneration through somatic embryogenesis was achieved in Astragalus adsurgens . Embryogenic callus was induced from hypocotyl, not root or cotyledon explants, and the maximum induction frequency (62%) was obtained on Murashige and Skoog (1962) basal medium (MS) containing 2.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/l N 6 -benzylaminopurine (BA). Transfer of embryogenic calli to MS medium with 1–2 mg/l BA and 0.1 mg/l α-naphthaleneacetic acid (NAA) resulted in somatic embryogenesis at high frequencies (63–74%) with an average of 280 somatic embryos per gram of embryogenic callus. After transfer onto half-strength MS medium without growth regulators, approximately 80% of somatic embryos developed into complete plantlets. Chromosome count of root tips from regenerants revealed a normal diploid. The rooted plantlets were successfuly transferred to soil with 60–80% survival, and the plants showed normal morphological characteristics. On MS medium containing 1.0 mg/l 2,4-D and 0.5 mg/l BA, embryogenic calli have retained morphogenetic potential for 12 months.