Somatic embryogenesis and plant regeneration in Heracleum candicans Wall

A protocol has been developed for achieving somatic embryogenesis and plant regeneration from petiole-derived callus of Heracleum candicans Wall. Callus was initiated on MS medium supplemented with 0.5 mg l^-1 2,4-D and 0.5 mg l^-1 BAP and subcultured on a medium containing double strength MS macrosalts, 1 mg l^-12,4-D and 0.25 mg l^-1 Kn. Numerous globular embryos were formed on the surface of the callus upon transfer to auxin-rich MS medium that lacked cytokinins. The globular embryos differentiated into mature embryos only when 2,4-D was removed from the medium. Mature embryo formation was significantly influenced by the pH of the medium and the addition of AgNO₃ and ABA. Eighty-five percent of the somatic embryos were converted into plantlets when transferred to a medium supplemented with 0.01 mg l^-1 BAP and 0.01 mg l^-1 IBA. The regenerated plants have been established in soil and appear to be identical to the parent plants in morphology and chromosome number.