StatusThe thesis was presented on the 10 December, 2019 at the meeting of the Scientific Council and now it is under consideration of the National Council.
Abstract– 0.85 Mb / in romanian
5.71 Mb /
The thesis contains an introduction, four chapters, general conclusions, recommendations, and a bibliography of 333 titles, 18 annexes, 143 pages of basic text, 58 figures, and 13 tables. The results are reflected in 36 scientific papers.
Aim of the study: assessment of the accumulation of active components in the rhizomes of plants of the Carpathian population R. rosea (Romania), as well as plants grown in vivo in order to evaluate the scientific basis of the relationship “genotype – medium – metabolic processes” for developing the methods of optimizing the accumulation of secondary metabolites in R. rosea cells, cultured in vitro.
The objectives of the study: determinization of the composition of SM and volatile oils in the R. rosea rhizomes collected in Romanian Carpathian Mountains and in rhizomes of plants cultivated in Moldova; introduction in vitro of the explants from R. rosea plants and determination of the influence of different physical and chemical factors, separately and in combination, on the biomass productivity and as well on the accumulation of various components of SM.
Originality and scientific novelty: for the first time, the composition of the SM as well as the volatile oil of R. rosea rhizomes collected in the Eastern Carpathian Maintains of Romania was determined. It was also demonstrated that the short-term exposure of cell culture to low temperature and UV radiation, as well as the introduction in the cultivation medium of cinamic alcohol and plant growth regulator (PGR) Reglalg, has a beneficial effect on the accumulation the SM, but their composition and content was lower compared to that characteristic for R. rosea rhizomes of spontaneous plants. The result obtained in solving an important scientific problem consists in the elucidation that short-term application of low temperatures and UV radiation, the introduction of cinnamic alcohol and PGR Reglalg in the culture medium at the beginning of the exponential phase of cell culture growth, assures the stimulation of the accumulation of SM in R. rosea biomass under in vitro conditions the open the possible ways to optimize the regimens of in vitro cultivation the R. rosea cells for obtaining the SM characteristics for rhizomes of spontaneous growing plants.
Theoretical value: Results of short-term exposure to UV radiation and low temperature of in vitro culture gives the possibility to conclude that such factors as daily and seasonal thermoperiodicity, UV radiation, the diurnal variation of the relative air humidity, characteristic for natural conditions in the mountains, are decisive factors which determines both the composition and the accumulation of active principles in rhizomes, as well as the for viability of the R. rosea plants. Cell culture of R. rosea represents an alternative method and a model for investigation the influence of the level of biological organization on the plants ability to accumulate SM and as well as the influence of physical and chemical factors on these processes.
Application value: in vivo and in vitro investigations have shown that for obtaining the active components characteristic for R. rosea, it is necessary to assure UV illumination and thermoperiodicity that are natural for spontaneous growing R. rosea plants. Thus, the selection of optimal cultivation conditions of R. rosea in vivo and in vitro could ensure the preventing the species extinction due to the intensive collection of plants growing in natural conditions.
Implementation of scientific results: R. rosea callus culture is maintained during of 10 years in the IGFPP and continues to be used in the scientific researches of the mechanisms of regulation the biosynthesis of SM, and also as information used in the teaching programs of the State University „Dimitrie Cantemir”.