The effect of culture medium formulation on Pinus nigra somatic embryogenesis

The potential of immature zygotic embryos to produce embryogenic tissue was tested using culture media differed in inorganic salt composition as well as plant growth regulator content. Explants cultured on DCR as well as MLV media gave the highest initiation percentages with maximum values of 8.8% (MLV) to 10.4% (DCR). Plant growth regulators content (standard or reduced) had no profound effect on embryogenic tissue initiation. Somatic embryo maturation as well as germination was dependent on the cell line and salt composition of the medium. Plantlet regeneration occurred in three cell lines out of five tested. During the maturation process profound changes occurred in the internal organisation of somatic embryos such differentiation of root meristem in precotyledonary somatic embryos and formation of provascular strands in cotyledonary somatic embryos.