Abstract
The formation of white and compact rice callus cultures was promoted by preculturing mature seed -derived celli on the medium containing a high concentration of sucrose. The obtained white and compact callus had a high regenerating ability on the regeneration medium containing 5 × 10-5M kinetin. When mannitol was added to the medium at the same osmotic level as excess sucrose treatment, it offered the intermediate effect between 3% (control) sucrose and 69L (high concentration) sucrose. Scanning electron microscopic examination revealed that the calli which retained the high regenerating ability had a tendency to show a smooth-surfaced appearance.
