Abstract
We obtained the microtubers of Ise-imo from the multiple shoots formed by the tissue cultures of shoot-tip and node explants with solid or liquid MS medium. Shoot-tip explants cultured with benzyladenine (0.1—2 mg L-1 ; BA) and naphthalene acetic acid (0.1—0.5 mg L-1), or node explants cultured with BA (0.1—5 mg L-1) differentiated multiple shoots. Multiple shoots were maintained on a medium with 5 mg L-1 BA and their growth occurred on the subculture medium without plant growth regulators. Although microtubers were formed immediately after the addition of jasmonic acid (JA), they were formed without JA after a substantial time lag. More microtubers were formed in the dark than in the light but their enlargement was vice versa. Obtained microtubers (heavier than 120 mg FW) could be used successfully for the ordinary cultivation after storage in a refrigerator at 8°C for one month.
