Abstract
A reproducible system for the regeneration of plants via somatic embryogenesis is essential for the genetic transformation of sugi (Cryptomeria japonica). We established a new, simple and reliable procedure for somatic embryogenesis and the regeneration of sugi. Immature seeds were collected at the end of June from about 10-year-old sugi trees. After sterilization, immature zygotic embryos were used for the induction of embryogenic calli. Embryogenic calli were observed after 4 weeks of treatment, and they were transferred into the liquid medium for the induction of embryogenic cells and subcultured every 2 weeks. Embryogenic cells were plated on the regeneration medium containing activated charcoal and abscisic acid. The embryos in various stages were observed after about 4 weeks. The addition of phytosulfokine and polyethylene glycol stimulated dramatically the formation of somatic embryos. Induced somatic embryos germinated with synchronous sprouting of cotyledons, hypocotyls and roots. Most of the seedlings grew normally.
