HIGH-FREQUENCY PLANT-REGENERATION IN HELICONIA-PSITTACORUM LF

High frequency plantlet regeneration was induced from callus derived from shoot tips and thin cross sections of in vitro cultures of Heliconia psittacorum L.f. Fine nodular callus was initiated in the dark on semisolid Murashige and Skoog medium containing 0.5 g/l activated charcoal, 1.0 g/l casein hydrolysate and 80 muM 2,4-dichlorophenoxyacetic acid (2,4-D). Reducing the concentration of 2,4-D in the medium to 40 muM and subculturing at 6-week intervals enabled long-term maintenance of this regenerative callus. There was no appreciable loss in regeneration potential for over 18 months in these cultures. Development and regeneration of protocorm-like bodies into plantlets occurred when 2,4-D was withdrawn from the medium, Regenerated plants were successfully transferred to field conditions.