Effect of sucrose concentration on somatic embryogenesis in carnation (Dianthus caryophyllus L.)

Abstract: The effect of sucrose concentration was investigated on callus induction and differentiation of embryogenic callus derived from petal explants of carnation cultivar Nelson'. Embryogenic calli were produced on MS culture medium containing 9 uM 2,4-dichlorophenoxy acetic acid (2,4-D), 0.8 uM 6-benzyladenine (BA) and different concentrations of sucrose alone or in combination with sorbitol. In constant osmotic potential medium, number of explants containing embryogenic calli was significantly enhanced by increasing the sucrose concentration. Somatic embryos were induced on a hormone-free media containing various concentrations of sucrose alone or in combination with sorbitol. Different sucrose concentrations from 50 to 150 mM significantly increased somatic embryos. No callus and embryo formed when sorbitol was the sole carbon source. In the presence of a constant sucrose concentration, increasing the osmotic potential with sorbitol led to increase in the frequency of somatic embryos. In medium containing low concentration of sucrose (50 and 100 mM), reduced development of embryos was recorded. 90% of somatic embryos were regenerated to form the entire plantlets when they were transferred onto the half-strength MS culture medium containing 3% sucrose. Plantlets also continued to grow under greenhouse condition.