Abstract
Mesophyll protoplasts of Spinacia oleracea L. (cv. JIROMARU) were isolated from the in vitro-grown young seedlings by treatment of the enzyme solution containing 0.1% Pectolyase Y-23, 0.3% Cellulase ONOZUKA RS, CPW salts and 0.5M mannitol (pH 5.8). The most efficient cell division and colony formation occurred in a modified 1/2MS medium containing 5mg/l BA and 1mg/l 2, 4-D. Shoots were induced in the following four treatments: a combination of the callus formation medium containing 1mg/l BA and 10mg/l NAA with the 2 kinds of shoot formation media containing 1mg/l kinetin or 5mg/l zeatin; a combination of the callus formation medium containing 5mg/l BA and 5mg/l NAA with the shoot formation medium containing 5mg/l BA; a combination of the callus formation medium containing 5mg/l BA and 10mg/l NAA with the shoot formation medium containing 1mg/l kinetin. Regenerated shoots developed roots in the MS liquid medium containing 1mg/l IAA or IBA.
