Cytogenetic Characteristics of Embryogenic Cell Lines of Different Ages Obtained by Somatic Embryogenesis in Larix sibirica Ledeb

A cytogenetic study of four embryogenic cell lines (CLs)of Siberian larch (Larix sibirica Ledeb.)of different ages, including young (two 4-month and one 16-month)and long-term proliferating (11-year)CLs has been carried out. Three CLs are diploid, and their karyotypes contain the number of chromosomes typical for this species (2n = 24). A 16-month CL capable of forming somatic embryos is aneuploid (2n = 25). This CL is probably characterized by a trisomy in one of the submetacentric chromosome pairs. A long-term proliferating CL, from which viable fruiting clones have been obtained, retained a diploid number of chromosomes for all 11 years of cultivation and still remained genetically stable. The karyotype of coniferous plants is characterized by high stability, and the most species from the family Pinaceae, to which the genus Larix Mill. belongs, contain 24 chromosomes (2n = 24). Therefore, the detection of cytogenetically stable cell lines with an altered chromosome set is of great interest for genetic studies of this group of plants. The identification of stable diploid cell lines is important for genetic and breeding studies aimed at the creation of highly productive plantations with specified hereditary properties.