Direct somatic embryogenesis and plant regeneration in Peucedanum oreoselinum (L.) Moench.

Experiments were performed to determine the influence of medium composition and explant characteristics on somatic embryogenesis in Peucedanum oreoselinum (L.) Moench. Somatic embryogenesis occurred directly without an intervening callus proliferation phase from leaf, petiole and root explants cultured on Murashige and Skoog (1962) (MS) medium supplemented with 4.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D) in darkness. Somatic embryos were directly formed at cut edges or on the surface of leaf explants, around cut ends or along side surfaces of petiole and root explants. Embryo formation was significantly affected by explant position. Adaxial-side-up orientation of leaf explants significantly promoted embryogenesis in comparison with abaxial-side-up orientation. The development of proembryos to globular, heart-shaped, torpedo and cotyledonary stages was achieved on the MS medium without plant growth regulators (PGRs) under light conditions. Embryo formation and maturation was further enhanced by addition of proline (5 mM) in MS medium. The frequency of embryo formation was significantly higher for root explants (85%) in comparison with leaf explants (57%) or petiole explants (11%). This protocol facilitated the recovery of 38 plantlets per root explant within 80 days.