Abstract: Hb, Ma and Mc genotype mature zygotic embryos of loblolly pine were cultured on TE medium containing 1.0 mg / L NAA, 4.0 mg / L BA, 500 mg / L LH and 500 mg / L glutamine, and primary adventitious buds were formed on cotyledons and hypocotyl in 12 weeks. Zygotic embryos with primary adventitious buds were transferred to TE differentiation medium with 0.5 mg / L NAA, 0.5 mg / L IBA, 2 mg / L BA, 500 mg / L LH and 500 mg / L glutamine. After 6 weeks a lot of adventitious buds appeared. Among 3 genotypes, differentiation frequency of Hb genotype adventitious bud was 58.2% the highest. Direct adventitious buds which were cultured or elongation medium for 6 weeks were transferred to TE rooting medium supplemented with 0.1 mg / L IBA, 1.0 mg / L BA, 0.5 mg / L GA3, and the highest rooting frequency of adventitious bud was 46% in 6 weeks.

Key words: Pinus taeda