This study aimed to evaluate effects of types and concentrations of plant growth regulators in a half-strength Murashige and Skoog medium on somatic embryogenesis from protocorm-like bodies (PLBs) and
leaf segments of Dendrobium Sonia ‘Earsakul’ cultured for 8 weeks. It was found that media containing
thidiazuron (TDZ) either at 0.1, 0.3 and 1.0 mg/L alone or in combinations with 0.1 mg/L naphthaleneacetic
acid (NAA) or 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) provided no significant differences in
percentage of somatic embryogenesis (38.18-49%) from PLBs. Half strength MS supplemented with TDZ
either at 1 and 3 mg/L alone or combination with 0.1 mg/L NAA provided higher percentage of somatic
embryo formation and number of somatic embryo per explant more than supplemented with 0.1 mg/L NAA
alone. Low percentage of somatic embryogenesis was found from leaf segments. Leaf explants with the
dorsal surface in contact with a medium provided higher somatic embryogenesis (0-18.75%) than those
obtained from the explants with the ventral surface contact with culture medium (0.89-8.04%).
cultured for 8 weeks