THE EMBRYOGENIC POTENTIAL OF LONG-TERM PROLIFERATION CELL LINES OF <i>Larix sibirica in vitro</i>
The study of embryogenic potential of Larix sibirica was conducted using zygotic embryos of trees resistant to larch bud midge as explants. Immature isolated zygotic embryos and megagamethophytes of Larix sibirica were experimentally cultured on AI medium (Tretyakova, 2012). As a result of experiments, 15 proliferative cell lines (Cl) of L. sibirica were obtained from embryo culture. Cls differed in somatic embryo production, more specifically, in embryo quantity, size, and capability to mature, to germinate, and to form viable plantlets. The number of somatic embryos ranged from 2040 to 11103 per 1 gram of fresh weight of embryogenic callus (EC) in young (age up to one year) Cls. The proliferate activity of Cls are maintained during two-six years. Morphogenesis and maturation of somatic embryos are observed 45 days on the medium AI added by ABA. The number of mature somatic embryos ranged from 12 to 1220 per 1 gram of EC. Small somatic embryos of hybrid Cl5 did not mature on AI medium. Different anomalies are observed in the morphogenesis of somatic embryos: destruction of embryo domain development and cytokinesis. The minimum embryo anomalies were observed in Cl4. In this Cl viable embryos are 83.31±3.00 %. The germination of somatic embryo occurred on medium AI hormones and due to elongation of hypocotyls and roots. Somatic seedlings were transferred to soil substrate at the condition of growth-chamber and then to soil at the greenhouse of V. N. Sukachev Institute of Forest SB RAS in 2013. Thus, the collection of embryogenic cell lines of L. sibirica was created. This collection will be used in a plantation forest growing larch in Siberia.