PLANT-REGENERATION FROM CALLUS PROTOPLASTS OF THE FORAGE LEGUME ASTRAGALUS ADSURGENS PALL

A reproducible release of viable protoplasts was obtained from friable calli of Astragalus adsurgens. Protoplasts underwent sustained divisi ons and formed cell colonies when cultured in either liquid or agarose -solidified Kao and Michayluk (1975) protoplast medium (KM8P) suppleme nted with 1.5 mg/l 2,4-D, 0.5 mg/l BA and 0.5 M glucose. Compared to l iquid culture, agarose bead culture improved division frequency effect ively, the two culture systems showing a plating efficiency of 0.8+/-0 .5% and 6.5+/-0.7%, respectively. Upon transfer to Murashige and Skoog (1962) medium (MS) with 1-2 mg/l BA, alone or in combination with NAA or 2,4-D at 0.1 mg/l, the protoplast-derived calli produced complete plantlets through somatic embryogenesis. The maximum percentage of cal li producing somatic embryos (52.5+/-2.2%) occurred on MS medium conta ining 0.1 mg/l NAA and 1 mg/l BA, whereas the maximum number of calli regenerating plantlets (64.7+/-6.2) was obtained on MS medium with 0.1 mg/l NAA and 2 mg/l BA.