Fig. 1.

Protoplast isolation and regeneration from tomato (S. lycopersicum) cv. Red Setter. a Cotyledons and first true leaves from 21-d-old in vitro seedlings used for protoplast isolation. b Sliced cotyledons and first true leaves incubated in enzyme solution after 16 h under 25 °C before protoplast purification. c Dark green bands containing released intact protoplasts appeared at the interface of sucrose solution and wash solution after centrifugation. d Freshly isolated green protoplasts under microscope. e Cell division 5 d after protoplast isolation. f Callus formation derived from protoplasts embedded in alginate after 12 d from protoplast isolation. g Calli released from alginate and cultured on solid shoot regeneration Medium TSR-b with first regenerated shoots observed three months after protoplast isolation. h A regenerated plant with well-developed roots on root regeneration medium three months after protoplast isolation. i Regenerated plants moved to soil in biotron four months after protoplast isolation