INDUCTION OF SOMATIC EMBRYOGENESIS IN PINUS HELDREICHII CULTURE

The potential for somatic embryogenesis in zygotic embryo and megagametophyte cultures of Pinus heldre- ichii was examined. Somatic embryogenesis was initiated from megagametophytes containing immature zygotic embryos at early stages of development. An induction frequency of up to 6.7% was obtained on Gresshoff and Doy medium in the presence of 2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/l benzyladenine (BA). Formation and further proliferation of embryogenic tissue were achieved upon transfer of explants to a medium with reduced lev- els of growth regulators. Somatic embryos are being cultured for further development.