Abstract: Juglans mandshurica Maxim. is one of the most important component species of the mixed forest of the broadleaved species and Korean pine forest in the eastern mountains in Northeast China. Because of too much cutting, the resource is decreasing. Somatic embryogenesis is basic for the rapid development of population and research on artificial seeds and has important significance in genetic improvement. This study intended to establish a culture system that would induce somatic embryogenesis of J.mandshurica Maxim. Various plant growth regulators and their ratio were investigated with different explants of J.mandshurica Maxim. The results showed that the zygotic embryos were the best to induce embryogenic callus. May and June were the best period to collect explants for the induction. The best induction medium for embryogenic callus was MS supplemented with 1.0 mg·L^-1 2,4-D and 0.5 mg·L^-1 6-BA. The best medium for induction, development and differentiation of somatic embryos was MS supplemented with 60 g·L^-1 sugar, 700 mg·L^-1 CH without any growth regulation substances.

Key words: Juglans mandshurica Maxim., somatic embryogenesis, embryogenic callus