Regeneration of somatic embryos from protoplasts isolated from an embryogenic suspension culture of white spruce (Picea glauca).

Regeneration of white spruce (Picea glauca) somatic embryos from protoplasts derived from an embryogenic suspension culture was accomplished using a culture medium containing 2 mgl(-1) 2,4-D and 1 mgl(-1) 6-BAP. Divisions within 2 days led to plating efficiencies in the order of 24% after 9 days. A reduction in the osmoticum, necessary for sustained growth, was carried out gradually over 30 days. Embedding in agarose and culture in 5 cm petri dishes prior to transfer of agarose blocks to a bead type culture, led to the formation of somatic embryos as early as 23 days after isolation and yielded plating efficiencies in the order of 5-10% after 35 days culture.