Cytogenetic Stability of Young and Long-Term Embryogenic Cultures of Larix sibirica

We present the results of cytogenetic analysis of seven young and long-term cultured embryogenic cell lines (CLs) of Larix sibirica obtained by somatic embryogenesis. All CLs were found to be mixoploid. Three CLs (1, 2 and 6 years of cultivation) were the most stable cytogenetically with 91–96% cells having diploid chromosome number 2n=24, typical for the species. These CLs can be successfully used for the development of planting material and in clonal plantation forestry. At the same time, some embryogenic CLs were shown to possess various chromosome and genome mutations. We found two aneuploidy proliferating CLs (2n=25 and 28) capable of somatic embryo formation. One of the CLs analyzed in a current study was found to be cytogenetically unstable with chromosome numbers ranging from 24 to 35 and containing one-two micronuclei in the interphase cells. Fluorescent in situ hybridization (FISH) and morphometric analyses of karyotypes of these embryogenic CLs allow an assumption that the trisomy for one or several chromosomes is the most widespread type of genomic disturbances in embryogenic CLs of L. sibirica.