Improvement on the Efficiency of Somatic Embryogenesis from Spinach Root Tissues by Applying Various Sugars

Abstract

Spinach (Spinacia oleracea L.) root segments were cultured on a medium containing a half strength of inorganic salts in Murashige and Skoog's medium, 10 μM 1-naphthaleneacetic acid (NAA), 0.1 μM gibberellic acid (GA₃) and various kinds and concentrations of carbohydrates. For callus induction and somatic embryogenesis, spinach root segments effectively utilized glucose, fructose, sucrose, maltose, or raffinose as a carbon source. Frequency of embryo formation increased inversely to sugar concentration. Fructose or raffinose increased the number of embryos per callus. Levels of sugars remained were measured in a raffinose-containing liquid culture medium in which root segments were cultured continuously. The fact indicates that fructose was preferentially utilized by the tissues of spinach. These results show that a low concentration of fructose in the culture medium promotes a high frequency of embryogenesis in spinach tissue culture.