EMBRYO CULTURE AND TAXANE PRODUCTION IN TAXUS SPP

We have previously shown (Flores and Sgrignoli, 1991) that immature em bryos of Taxus brevifolia and T. X media are capable of precocious ger mination and can grow into seedlings in vitro. The cultural and enviro nmental parameters for embryo germination and conversion into seedling s have been optimized and extended to T. baccata and T. cuspidata. A 1 4-h photoperiod improved embryo germination and growth into seedlings. A pregermination cold treatment of the seeds had a positive effect on both the onset and percentage of germination. Embryos from cold-treat ed seeds germinated earlier and at a higher frequency than those from control seeds. Boron was necessary for embryo germination, and levels of this micronutrient were established for optimal growth and germinat ion of T. brevifolia and T. X media cv. Hicksii embryos. Gupta and Dur zan's medium was superior to White's for embryo germination and root f ormation. Naphthaleneacetic acid stimulated root formation in embryo-d erived seedlings. We also found that immature embryos could be induced to form callus with embryogenic potential. Taxol and related taxanes were detected in embryo- derived seedlings.