Some problems arising during the initiation of somatic embryogenesis in Pinus sylvestris L.

The use of biotechnological tools in particular somatic embryogenesis (SE) for mass propagation of conifers is relevant, since this method allows to quickly replicate plant material with desired features. However, there are still a number of difficulties in obtaining embryogenic cell culture for Pinus sylvestris. One of the important and unsolved problems is the search for SE-competent genotypes. 674 megagametophytes from 22 donor plants (16 genotypes) were cultured in vitro during 2021 summer period. As a result of the experiment, callus formation was not recorded for the studied genotypes, however, 9.4±1.0% of the explants formed plants. In addition to the genotype effect, unsuitable nutrient medium or late developmental stages of zygotic embryos could be the reasons for the lack of callus induction. To solve these problems, a number of studies were carried out: (1) the effect of the nutrient medium composition and density (MS, MSG, ½LV, DCR) on the callus initiation from mature seeds was analysed, (2) the effect of various growth regulators concentrations on the initiation of callus formation was studied, (3) the analysis of the reproductive competence of donor plants was perfomed by the method of vegetative buds cultivation. As a result, several genotypes were found to have the ability for embryogenic callus formation, and the conditions for explants cultivation were selected.