Features of the dynamics of the initial stages of ontogenetic development Calycanthus floridus L. in vitro

Abstract

Aims. Studying the dynamics of individual growth and development of plants in vitro, in the early stages of ontogeny, to find out the changes that occur in explants under the action of phytohormones at different ages is the aim of our research. Methods. The work was performed in the laboratory of microclonal propagation of plants of the National Dendropark «Sofiyivka» of the National Academy of Sciences of Ukraine. The study of age states of Calycanthus floridus L. plants was carried out by germination of seeds on agarized, nutrient media according to Murashige and Skoog (MS) prescription. To determine the efficiency of growth and development of explants at different ages, nutrient media modified by the addition of phytohormones were used: 6-benzylaminopurine (6-BAP) –– 0.1–1.0 mg/l, indole butyric acid (β- IBA) –– 0.01–0.20 mg/l and cysteine –– 0.5–1.5 mg/l. Results. The data obtained during the experiment showed that the growth of explants of C. floridus in vitro consists of several successive age stages, during the passage of which both hereditary information of the organism (genotype) and phenotype are realized –– a set of all signs and properties of the plant, which largely depended on the content and concentrations of phytohormones in the nutrient media. In explants of C. floridus, cultured on Murashige and Skoog (MS) nutrient media, modified by the addition of 6-BAP 0.5 mg/l, β- IBA 0.08 mg/l, and 1.0 mg/l cysteine, revealed an active change in the formation of morphological structures and the onset of the initial stages of ontogenesis. Conclusions. In vitro cultured explants of C. floridus, obtained from sowing seeds on nutrient media, underwent a latent period of growth and five age states: embryonic (se), seedling (pl), juvenile (j), immature (im), and virgin (v). The formation of morphological structures was most active on the nutrient medium modified by the addition of 6-BAP 0.5 mg/l, β- IBA 0.08 mg/l, and cysteine 1.0 mg/l.