Microtuber formation in micropropagated Jerusalem artichoke (Helianthus tuberosus)

Clonal micropropagation of Jerusalem artichoke (Helianthus tuberosus L.) wa s initiated from axillary meristems of lateral shoots of field-grown plants on medium with MS salts, 2% sucrose, 1 mg l(-1) thiamine-HCl, 1 mg l(-1) I AA and 0.6% agar. Plantlets were cut into nodal sections and used for subse quent subcultures and for microtuber induction. Microtubers were induced fr om axillary meristems on medium with half-strength MS salts, 8% sucrose and 0.5 mg l(-1) BA in darkness at 18 degrees C. They had near to 30% of dry m atter. Microtubers resumed growth in light room at 23 degrees C after 4-6 m onths of cold storage.