[Embryo initiation from Pinus sibirica megagametophytes in in vitro culture].

Megagametophytes of Siberian pine were cultured on an in vitro culture medium 1/2 LV supplemented with growth regulators 2,4-dichlorophenoxyacetic acid (2,4-D) and benzylaminopurine (6-BAP) to form embryos. The competency of somatic cell of explants to embryogenesis manifested itself in an organized growth and polarity. A coenocyte consisting of long vacuolated cells was formed in the megagametophyte culture. Then, the migration of the nuclei to one of the poles of the cell, their division, and formation of embryoids was observed. The megagametophyte culture of the Siberian pine differed from the zygotic embryo culture by the absence of asymmetric division in the vacuolated cell.