Effect of plant growth regulators on direct somatic embryogenesis in camphor tree (Cinnamomum camphora L.) from immature zygotic embryos and embryogenic calli induction

A description of a successful direct somatic embryogenesis induction from immature zygotic embryos of a camphor tree (Cinnamomum camphora L.) is presented. After a subculture of 2-3 years, embryogenic calli could be derived from primary somatic embryos. Immature zygotic embryos were cultured on a Murashige and Skoog (MS) basal medium supplemented with a range of combinations of cytokinins (BA) and auxins (2,4-D or NAA) for somatic embryo induction. Primary somatic embryos could be induced directly in almost all PGR combinations. A positive effect of 2,4-D on somatic embryogenesis from immature zygotic embryos of camphor tree was obtained. BA at appropriate concentrations (<5 mg·L^-1) had an effect similar to 2,4-D, whereas high concentrations (>5 mg·L^-1) of BA had the effect of restraining somatic embryo induction. NAA had a less positive effect on somatic embryogenesis than 2,4-D.