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.