Isolation, culture and plant regeneration from mesophyll protoplasts of Digitalis obscura

High yields of protoplasts were obtained from mesophyll tissue of Digitalis obscura L. Osmotic potential of the isolation medium and Ca²⁺ were important in obtaining a high viability of the preparations. In different culture techniques employed, liquid-over-agar-solidified medium was superior to liquid medium alone. Agar plating technique was ineffective. On Murashige and Skoog modified medium with casein hydrolysate and several indoleacetic acid and benzyladenine combinations, isolated protoplasts underwent sustained mitotic division and produced calli. The calli formed shoots when transferred to regeneration media. Regenerated shoots could be easily rooted and developed into whole plants on half-strength Murashige and Skoog hormone-free medium.