Georgina Kosturkova

Enrichment of Pisum sativum gene resources through combined use of physical and chemical mutagens

The potential of induced mutations is of importance in genetic improvement of crops. In the experiments different physical and chemical mutagens were used (g-rays, fast neutrons, ethyl methanesulfonate (EMS), ethylene imine (EI), diethyl sulfate (DES), and nitroso methyl urethane (NMU)) applied in single or combined treatments. Frequency of main mutations was considerably higher after combined treatment compared to single treatment. Combined treatment with 150 Gy and 0.01% NMU caused a hyper-additive mutation effect (4.76%), double the theoretically expected one. The chemical mutagen concentrations had considerable influence on the effect of the combined treatment. The mutation spectrum also differed in various kinds of treatments. Significant changes in the mutagen efficiency occurred with the increase of EMS concentrations in combined treatment with g-rays. The highest efficiency coefficient (3.65) was obtained in the variant with 40 Gy g-rays and 0.2% EMS, which correlates with the highest mutation fre...

The Role of Biotechnology for Conservation and Biologically Active Substances Production of Rhodiola rosea: Endangered Medicinal Species

At present, more than 50 000 plant species are used in phytotherapy and medicine. About 2/3 of them are harvested from nature leading to local extinction of many species or degradation of their habitats. Biotechnological methods offer possibilities not only for faster cloning and conservation of the genotype of the plants but for modification of their gene information, regulation, and expression for production of valuable substances in higher amounts or with better properties. Rhodiola rosea is an endangered medicinal species with limited distribution. It has outstanding importance for pharmaceutical industry for prevention and cure of cancer, heart and nervous system diseases, and so forth. Despite the great interest in golden root and the wide investigations in the area of phytochemistry, plant biotechnology remained less endeavoured and exploited. The paper presents research on initiation of in vitro cultures in Rhodiola rosea and some other Rhodiola species. Achievements in induction of organogenic and callus cultures, regeneration, and micropropagation varied but were a good basis for alternative in vitro synthesis of the desired metabolites and for the development of efficient systems for micropropagation for conservation of the species.

Bulgarian golden root in vitro cultures for micropropagation and reintroduction

Rhodiola rosea is an endangered medicinal plant used for cancer, cardiovascular, and nervous system diseases therapy. Due to its limited distribution and sustainability alternative methods for production of its valuable substances are under investigation. Using in vitro techniques apical and rhizome buds, leaf nodes, stem and radix segments from wild plants and in vitro seedlings were plated on 24 modified Murashige and Skoog (1962) media. Decontamination of plant material was successful only in 21% of the schemes. The best shoot induction was obtained from seedling explants on media containing 2 mg/l zeatin or N6-benzylaminopurine, each. Their reduction stimulated shoot formation in the next passages (multiplication rate up to 5). Efficient rooting was induced on half-strength MS with 2 mg/l Indole-3-butyric acid and stimulated by adding 0.2 mg/l Indolyl-3-acetic acid. Regenerants rooted in perlite, peat, and soil (1:1:2), adapted in greenhouse, and transplanted in the mountains survived (70%) and developed like the wild plants. Salidroside content of these plants after one or two years was high (0.64 and 0.61% in rhizomes and 0.62 and 0.53% in roots, respectively). This is the first established efficient scheme for micropropagation of Bulgarian R. rosea allowing habitats restoration, germplasm conservation, and potential application of biotechnology for production of valuable substances.

A Soft Computing QSAR Adapted Model for Improvement of Golden Root in Vitro Culture Growth

ABSTRACT Golden Root is a rare medicine plant, difficult for cultivation, with a wide potential in treating cardiovascular and other diseases because of its biologically active compounds. Therefore there are researches about in vitro cultivation of Rhodiola rosea. It is well known that biotechnological experiments provide slowly and in a non-efficient way the needed protocols about multiplication, growing and rooting in in vitro nutrient media. The previously collected data of such experiments were analyzed and computationally trained in order to identify the nutrient media that give the best results for growing and rooting, taking into account the limitations such as insufficiency of the plant material and in vitro nutrient media cost. The proposed analysis contributes to the optimization of biotechnology experiments giving new directions for the theoretically fitting quantity of nutrient medium ingredients necessary for in vitro growth and rooting of Golden root, taking into account criteria such as biology and cost effectiveness concerning the experiment and results. “Similar biological activity is provided by common structural properties”—this is the main concept of modeling by Quantitative structure—activity relationship model (QSAR), which is a common method used for property prediction of biochemistry molecules and drugs. Based on this we adapted the concept, making the following assumptions: “biological activity” can be every result from an in vitro experiment such as the type of developed tissue and percentage of necrotic tissues; “structural properties” can be the properties of the nutrient medium, i.e. the concentrations of chemical compounds in the medium. QSAR could be defined as a method based either on regression models, or on artificial intelligence models. Here Artificial Neural Networks is proposed as a soft computing method for creating a model of dependences between nutrient medium, type of explant, type of nutrient medium, cultivation days, medium price and the initial response during the in vitro cultivation. Forecast results were subjected to applied basic statistical analysis, clustering and graphical interpretations.

Application of Alfalfa Protoplast Cultures in Genetic Studies

ABSTRACTSome of the applications of Medicago protoplast cultures in mutagenesis, selection and genetic transformation studies are demonstrated. The establishment of reliable protoplast systems with high viability, cell division and regeneration capacity is a prerequisite for successful investigations. When different kinds of treatment were applied, it was important to compromise between the most effective parameters of treatment, protoplast viability and expected genetic changes.

Contribution of Bulgarian Women to Plant Biotechnology: Institute of Genetics Case

Plant biotechnology emerged in the 1950s and had an immediate positive impact on many fields of science, agriculture and industry. Since 1970, in Bulgaria more than 20 research units of in vitro culture were established utilizing a wide range of methods. Allocation of resources for plant biotechnology is still increasing in most bioscience institutes. Concerning gender – work with in vitro cultures in Bulgaria attracts predominantly women, who represent more than a half of the staff in two big units (in the Institute of Genetics, BAS and the University of Plovdiv) or all the personnel in small laboratories. Regarding level of positions, female researchers predominantly hire female assistants, while leadership depends on personal abilities, rather than gender. The specificity of biotechnology work needs certain attributes traditionally found in women, such as skilled hands, quick fingers, gentle action, patience and creativity. The Department of Plant Biotechnology of the Institute of Genetics has joined in the world tendencies of development and application of plant biotechnology in science, agriculture and industry. Its main achievements are in the area of induced organogenesis and androgenesis, somaclonal variation and modification of plant genomes, modeling of stress and micropropagation of valuable and endangered species, contributing to enrichment of genetic diversity and protection of biodiversity.

Expression of Foreign Genes Following Electroporation of Medicago Protoplasts

ABSTRACTElectroporation is one of the methods for direct gene transfer. When it is applied a lot of parameters influence protoplast viability and gene uptake. This makes important to follow transient gene expression before stable transformation. Protoplasts from Medicago sativa and M. varia were electroporated with p DW2-DNA. CA T activity was determined to be as high as the standard bacterial enzyme in protoplast samples. The electroporation parameters determining high transient gene expression determined higher kanamycine resistance of protoplasts electroporated with pCa MVNEO-DNA. Regenerated plants preserved the antibiotic resistance.