Culture in vitro of Megagametophytes and Embryos of Siberian Coniferous Species

摘要

Coniferous species are the most difficult objects for studying these in culture in vitro. Therndifficulties of introduction in culture of this species are caused by duration of formation of generativernorgans, weak regenerative ability, formation of under-developed embryos, which need a longrnstratification.rnThe experiments in growing seedlings in vitro from fertilizing egg cells and immature embryosrnof Siberian pine and Siberian larch were carried out. Cultivation of megagametophytes in the periodrnfrom egg cell formation to early embryo on the MS medium supplemented by hormones allows tornmanipulate events of fertilization and embryo development. Cultivation of immature embryos at thernstage of their early differentiation with megagametophytes has shown that embryogenesis is notrnstopped. In three months of cultivation the germination of these embryos begins and seedlings form.rnThe immature embryos are the more perspective for cultivation in vitro. Maturation of embryos andrndevelopment of seedlings occur in 7 days.rnThe cultivation of zygotic embryos of Siberian pine and Siberian larch showed the regenerationrnof adventive buds at the base and at the top of cotyledons. Subcultivation of adventive buds showedrnthat the active development of callus is observed in 30 % of explants. The 7-10 meristems form inrncallus de novo. Thus, cultivation of megagametophytes of coniferous species shows the formation ofrnembryological structures in vitro and viable seedlings.