Protoplast culture and plant regeneration ofPinellia ternata.

A study was undertaken to develop a protoplast regeneration system for pinellia. A yield of 19 29 x 10(5) protoplasts/g F. W. could be obtained from cell suspension cultures incubated in a digestion enzyme solution with 2% cellulase Onzuka R-10, 10% pectinase (Sigma), 0.01% pectolyase Y23. K8P and modified MS media were used to culture protoplasts in: a) liquid, b) liquid-solid double layer, or c) agarose embedded protoplast culture. The former two were conducive to colony formation from protoplast-derived cells. The frequency of cell division was about 8% after 3 days in culture. Gradually adding fresh medium of lower osmotic pressure into the medium for protoplast culture favored cell division. Calli (1-2 mm in diameter) formed after 30-40 days in culture. The calli transferred onto medium supplemented with KT (0.5 mg 1(-1)) and NAA (0.2 mg 1)(-1)) could regenerate plants after 40-50 days. Of 47 plantlets transplanted into plots, 29 flowered and were fertile.