Key Techniques for Somatic Embryogenesis and Plant Regeneration of Pinus koraiensis

Abstract

Korean pine is the dominant species of Korean pine forests. It is an economically valuable species that yields oil, high-quality timber and nuts, and it offers great prospects for further development. Complete regenerated plants of Korean pine were obtained via somatic embryogenesis using megagametophytes as the explant. The seeds of 27 families of Korean pine were collected to induce embryogenic lines. We compared the effects of explant collection time, family and medium components (concentrations of sucrose, plant growth regulators and acid-hydrolyzed casein) on embryogenic lines induction. The effects of plant growth regulators and L-glutamine contents on the proliferation and maturation of embryogenic cell lines were studied, and the germinating ability of different cell lines was evaluated. The embryogenic lines induction percentage of Korean pine reached 33.33%. When 4.52 μmol·L−1 2,4-D and 2.2 μmol·L−1 6-BA were added to the medium of embryogenic lines proliferation, the ability of embryo maturation was the best (cell line 001#-100 was 135.71·g−1 fresh weight). Adding 1–1.5g L−1 L-glutamine to the proliferation medium can improve the ability of embryo maturation (cell line 001#-100 was 165.63·g−1 fresh weight). The germination percentage of the three cell lines tested was significant, and the highest was 66%. We report on successful regeneration and cryopreservation methods for somatic embryos of Korean pine. This technology could be used to propagate the excellent germplasm resources of Korean pine and to establish multi-varietal forestry.