Abstract: Protoplasts were isolated from leaves of regenerated plantlets of Astragalus tenuis. Calli were formed from protoplasts cultured in modified K8p medium. After calli were transferred to differentiated medium plantlets were regenerated. The plantlets rooted on a rooting medium. No callus was able to be obtained when mesophyll protoplasts from regenerated plantlets were cultured in AY medium, nor when mesophyy protoplasts from seedlings were cultured in modified K8p or AY media. Lower concentrations of 2,4-D were favourable for callus formation and differentiation, while high concentrations of 2,4-D reduced the capacity of the callus growth and differentiation.

Key words: Astragalus tenuis, Mesophyll protoplast, Plant regeneration