Krasi Tasheva - Academia.edu (original) (raw)

Papers by Krasi Tasheva

Rhodiola rosea L. (Golden Root, Roseroot) is an endangered species and is protected by law in Bul... more Rhodiola rosea L. (Golden Root, Roseroot) is an endangered species and is protected by law in Bulgaria and other countries. Rhizome and roots extracts are used as a stimulant of immune system, adaptogen, and for prophylactics and cure of socially important diseases – cancer, cardiovascular, etc. Schemes for in vitro propagation and plant regeneration were established previously. The aim of the present work was to morphologically and cytologically characterize the regenerants. Concerning flowers, leaves, stem and rhizomes no differences were recorded between the wild plants and the regenerated plants grown ex vitro in the adaptation room, in the green house and in the mountain. To detect chromosome number, commonly used techniques for squash preparations were modified to be used for root tip meristem cells of Rhodiola rosea regenerants. In vitro plants obtained on different culture media were subjected to cytological analysis. The chromosome number in all samples was 2n = 22, which c...

Central European Journal of Biology, 2010

Rhodiola rosea is an endangered medicinal plant used for cancer, cardiovascular, and nervous syst... more 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 su...

Plants

Genetic diversity and population structure are key resources for breeding purposes and genetic st... more Genetic diversity and population structure are key resources for breeding purposes and genetic studies of important agronomic traits in crops. In this study, we described SNP-based genetic diversity, linkage disequilibrium and population structure in a panel of 179 bread wheat advanced cultivars and old accessions from Bulgaria, using an optimized wheat 25K Infinium iSelect array. Out of 19,019 polymorphic SNPs, 17,968 had a known chromosome position on the A (41%), B (42%) and D (11%) genome, and 6% were not assigned to any chromosome. Homoeologous group 4, in particular chromosome 4D, was the least polymorphic. In the total population, the Nei’s gene diversity was within the range 0.1–0.5, and the polymorphism information content ranged from 0.1 to 0.4. Significant differences between the old and modern collections were revealed with respect to the linkage disequilibrium (LD): the average values for LD (r2), the percentage of the locus pairs in LD and the LD decay were 0.64, 16% a...

Classification of major secondary metabolite groups is described. A short account is also given t... more Classification of major secondary metabolite groups is described. A short account is also given to ultraviolet (UV) climatology and UV response in plants. Investigations regarding secondary metabolite production in plants, in vitro cultivated plant cell and tissue cultures under UV radiation, particularly UV-B (280-315 nm) and UV-C (200-280 nm) are reviewed. The capacity of plants, callus and tissue cultures to accumulate secondary metabolite compounds after exposure to UV is discussed. The cell and tissue cultures possess high potential for production of valuable secondary metabolites under controlled conditions, and it seems perspective to enlarge the investigations in this direction by using low doses of UV as elicitors of such compounds.

Acta Horticulturae, 2012

ABSTRACT Export Date: 18 October 2014

The aim of this study was to determinate the quantity of salidroside in one and two year old Rhod... more The aim of this study was to determinate the quantity of salidroside in one and two year old Rhodiola rosea L. samples, propagated in vitro, in comparison with coeval ones, grown by seeds. The average content of the investigated substance in the rhizomes was 0.64% at the first and 0.61% at the second year and exceeds that of the marker individuals. These results indicate the in vitro propagation as a possible way to receive a plant material of good quality.

The Scientific World Journal, 2012

At present, more than 50 000 plant species are used in phytotherapy and medicine. About 2/3 of th... more 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 roseais 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 ofin vitrocultures inRhodiola roseaand some otherRhodiola species. Achievements in induction o...

Environmental Biotechnology - New Approaches and Prospective Applications, 2013

Biotechnology & Biotechnological Equipment, 2013

Golden Root is a rare medicine plant, difficult for cultivation, with a wide potential in treatin... more 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.

Rhodiola rosea L. (Golden Root, Roseroot) is an endangered species and is protected by law in Bul... more Rhodiola rosea L. (Golden Root, Roseroot) is an endangered species and is protected by law in Bulgaria and other countries. Rhizome and roots extracts are used as a stimulant of immune system, adaptogen, and for prophylactics and cure of socially important diseases – cancer, cardiovascular, etc. Schemes for in vitro propagation and plant regeneration were established previously. The aim of the present work was to morphologically and cytologically characterize the regenerants. Concerning flowers, leaves, stem and rhizomes no differences were recorded between the wild plants and the regenerated plants grown ex vitro in the adaptation room, in the green house and in the mountain. To detect chromosome number, commonly used techniques for squash preparations were modified to be used for root tip meristem cells of Rhodiola rosea regenerants. In vitro plants obtained on different culture media were subjected to cytological analysis. The chromosome number in all samples was 2n = 22, which c...

Central European Journal of Biology, 2010

Rhodiola rosea is an endangered medicinal plant used for cancer, cardiovascular, and nervous syst... more 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 su...

Plants

Genetic diversity and population structure are key resources for breeding purposes and genetic st... more Genetic diversity and population structure are key resources for breeding purposes and genetic studies of important agronomic traits in crops. In this study, we described SNP-based genetic diversity, linkage disequilibrium and population structure in a panel of 179 bread wheat advanced cultivars and old accessions from Bulgaria, using an optimized wheat 25K Infinium iSelect array. Out of 19,019 polymorphic SNPs, 17,968 had a known chromosome position on the A (41%), B (42%) and D (11%) genome, and 6% were not assigned to any chromosome. Homoeologous group 4, in particular chromosome 4D, was the least polymorphic. In the total population, the Nei’s gene diversity was within the range 0.1–0.5, and the polymorphism information content ranged from 0.1 to 0.4. Significant differences between the old and modern collections were revealed with respect to the linkage disequilibrium (LD): the average values for LD (r2), the percentage of the locus pairs in LD and the LD decay were 0.64, 16% a...

Classification of major secondary metabolite groups is described. A short account is also given t... more Classification of major secondary metabolite groups is described. A short account is also given to ultraviolet (UV) climatology and UV response in plants. Investigations regarding secondary metabolite production in plants, in vitro cultivated plant cell and tissue cultures under UV radiation, particularly UV-B (280-315 nm) and UV-C (200-280 nm) are reviewed. The capacity of plants, callus and tissue cultures to accumulate secondary metabolite compounds after exposure to UV is discussed. The cell and tissue cultures possess high potential for production of valuable secondary metabolites under controlled conditions, and it seems perspective to enlarge the investigations in this direction by using low doses of UV as elicitors of such compounds.

Acta Horticulturae, 2012

ABSTRACT Export Date: 18 October 2014

The aim of this study was to determinate the quantity of salidroside in one and two year old Rhod... more The aim of this study was to determinate the quantity of salidroside in one and two year old Rhodiola rosea L. samples, propagated in vitro, in comparison with coeval ones, grown by seeds. The average content of the investigated substance in the rhizomes was 0.64% at the first and 0.61% at the second year and exceeds that of the marker individuals. These results indicate the in vitro propagation as a possible way to receive a plant material of good quality.

The Scientific World Journal, 2012

At present, more than 50 000 plant species are used in phytotherapy and medicine. About 2/3 of th... more 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 roseais 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 ofin vitrocultures inRhodiola roseaand some otherRhodiola species. Achievements in induction o...

Environmental Biotechnology - New Approaches and Prospective Applications, 2013

Biotechnology & Biotechnological Equipment, 2013

Golden Root is a rare medicine plant, difficult for cultivation, with a wide potential in treatin... more 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.