Plant Regeneration from Hypocotyl-derived Calli of Spinach (Spinacia oleracea L.) and Anatomical Characteristics of Regenerating Calli

Abstract

Plant regeneration and/or embryogenesis from callus and/or protoplast are necessary for selection of various tolerances such as acid-and pesticide-tolerance and for the formation of transgenic plants. In this experiment, we studied callus induction from hypocotyl segment, plant regeneration from hypocotyl-derived calli and anatomical structures of regenerating calli of spinach cv. Sunlight. Calli were induced on MS medium containing 7 .0mg/l of NAA. Shoots without roots were obtained from calli, which were precultured on 0.1mg/l of IAA without GA3i upon transfer on to hormone-free MS medium. Contrastingly, calli which were precultured with the following hormone combinations, i. e. 1.0mg/l of IAA and 1.0mg/l of GA3i 5.0mg/l of IAA and 0.1mg/l GA3 and 5.0 mg/l of IAA and 1.0mg/ l of GA3 showed plant regeneration. In these calli, vascular bundle tissues that connect shoots and adventitious roots were observed. The present results indicate the significant effect of GA3 in the culture medium in assuring plant regeneration in spinach.