Emil D Molle | Printnem (original) (raw)

Papers by Emil D Molle

Proceeding of the Bulgarian Academy of Sciences, 2013

Forage productivity and quality are the most significant traits of alfalfa (Medicago sativa L.). ... more Forage productivity and quality are the most significant traits of alfalfa (Medicago sativa L.). The objective of that study was to compare the photosynthetic properties of some trifoliolate and multifoliolate alfalfa genotypes. Plants were selected at the Institute of Agriculture and Seed Science "Obraztsov chiflik"-Ruse. MF23 multifoliolate alfalfa line and the two trifoliolate ones with high and low productivity and standard variety Prista 2 were investigated. The studied fluorescence parameters indicate the lack of differences between low and high yield alfalfa trifoliolate populations irrespective of their different productivity, while MF23 shows enhanced PSII down-regulation, which relates to a higher potential to adjust MF23 to environmental changes. Better adjustment to the environment is one of the factors that determine higher productivity of MF23 in comparison to multifoliolate alfalfa plants studied previously.

In Vitro Cellular & Developmental Biology - Plant, 2008

The investigation deals with in vitro clonal propagation of L. aestivum L. (Summer Snowflake), a ... more The investigation deals with in vitro clonal propagation of L. aestivum L. (Summer Snowflake), a threatened Amaryllidaceae plant species in Bulgaria used in the pharmaceutical industry as raw material for production of galanthamine-based medicines. Plants of known origin and with different alkaloid profile were taken from the living collection of the Institute of Botany, Sofia. Bulbs were used to initiate in vitro cultures and 24 clones were multiplied. The influence of the clone origin on the propagation coefficient, shoot and bulblet morphology, alkaloid profile and content of galanthamine, lycorine, and four related alkaloids was evaluated. Clones kept stable alkaloid profiles and for most of them, high regeneration rates were noted. Galanthamine content of some clones was commensurable with that of Bulgarian populations of L. aestivum of commercial importance. Five clones: four galanthamine-type and one lycorine-type were selected as promising for further investigation.

Engineering in Life Sciences, 2012

The results described in these studies proved that the successful in vitro bioproduction of galan... more The results described in these studies proved that the successful in vitro bioproduction of galanthamine from L. aestivum shoot-clumps required mainly the selection of in vitro clones with a genetically determined high ability to produce the desired alkaloids, although the expression of this ability could be additionally influenced by diverse exterior factors, such as some components of the nutrient medium, or the cultivation conditions of the ambience. Tissue differentiation was also of great importance for the biosynthetic capacity of the cultures. The most suitable inocula for in vitro biosynthesis of galanthamine in liquid medium were the directly regenerated shoot-clumps, ensuring high alkaloid concentrations between 1 and 2 mg/g DW for the selected clones. We observed astonishing clone-specific dynamics of the biosynthetic activity of all of the studied in vitro clones. The dynamics were obviously related to the strong biological clock of the species, persisting even in several-year old cultures. These dynamics did not coincide with those usual for the plants growing in situ and under controlled field conditions. In our opinion, the clone specificity of the biosynthetic dynamics could be due to the disturbance of the plant regulation mechanism under the equal conditions of the ambience in the culture room. The sharp decrease of the alkaloid concentrations were transient, followed by an increase, so that cultures were retaining their biosynthetic capacity. The biosynthesis of the main alkaloids, galanthamine and lycorine, was influenced by diverse stimulants such as substances causing stress (JA), feeding with alkaloid precursors (the amino acids phenylalanine and tyrosine, and CH), and physical treatment (acoustic waves). However, the course of the biosynthetic dynamics during the period of the treatments was always the most important factor for the success of secondary metabolism stimulation. As far as scaling-up of the in vitro biosynthesis of valuable compounds, a stable and predictable yield is required, and additional investigations aimed at the annulment of the effect plant biological clock on alkaloid biosynthesis are needed. The elucidation of the relative influences of the diverse factors modulating alkaloid biosynthesis was of great importance. The high galanthamine concentrations of the selected in vitro clones are a promising basis for future studies.

Biotechnology & Biotechnological Equipment, 2014

Genetic variability in modern crops is limited due to domestication and selection processes. Gene... more Genetic variability in modern crops is limited due to domestication and selection processes. Genetic variation in eight Bulgarian tomato varieties and breeding lines (variety Plovdivska karotina, variety IZK Alya, L21b, L53b, L1140, L1116, L975, L984) differing in their morphological and biochemical composition was assessed using a highly efficient and lowcost fluorescent simple sequence repeat (SSR) genotyping platform. Genotyping was conducted with 165 publicly available microsatellite markers developed from different research groups under a number of projects in tomato (SOL Genomics SSRs, Kazusa TGS and TES, SLM, TMS and LEMDDNa) among which only five (3.03%) failed to amplify the expected PCR fragments. Of the remaining markers, 81 (50.62%) were polymorphic in the whole collection of eight genotypes. Among the marker groups used, SLM markers were most polymorphic, followed by TMS and SOL Genomics SSR markers. The total number of amplified alleles was 299, with a mean of 1.869; and the average polymorphic information content (PIC) was 0.196. The genetic diversity within the collection was relatively low (0.2222). Nei's genetic distance varied from 0.0953 to 0.3992. Cluster analysis using the un-weighted pair group method with arithmetic mean (UPGMA) method indicated that the studied tomato genotypes are grouped in four main clusters, which is to some extent consistent with the morpho-and hemo-types of the studied tomatoes. Variety IZK Alya (cherry type) and two of the breeding lines (L1140, L1116) formed three separate and more distant clusters. The fourth cluster includes the other five genotypes. The observed grouping of these genotypes in two sub-clusters reflects their similar morphological and biochemical composition. The genetic distance information from this study might be useful for further implementation of breeding strategies and crosses among these inbred lines.

In Vitro Cellular & Developmental Biology - Plant, 2009

The investigation deals with in vitro clonal propagation of L. aestivum L. (Summer Snowflake), a ... more The investigation deals with in vitro clonal propagation of L. aestivum L. (Summer Snowflake), a threatened Amaryllidaceae plant species in Bulgaria used in the pharmaceutical industry as raw material for production of galanthamine-based medicines. Plants of known origin and with different alkaloid profile were taken from the living collection of the Institute of Botany, Sofia. Bulbs were used to initiate in vitro cultures and 24 clones were multiplied. The influence of the clone origin on the propagation coefficient, shoot and bulblet morphology, alkaloid profile and content of galanthamine, lycorine, and four related alkaloids was evaluated. Clones kept stable alkaloid profiles and for most of them, high regeneration rates were noted. Galanthamine content of some clones was commensurable with that of Bulgarian populations of L. aestivum of commercial importance. Five clones: four galanthamine-type and one lycorine-type were selected as promising for further investigation.

Comptes rendus de l'Académie bulgare des sciences: sciences mathématiques et naturelles

Directly regenerated shoot-clumps of Leucojum aestivum manifested high biosynthetic capacity duri... more Directly regenerated shoot-clumps of Leucojum aestivum manifested high biosynthetic capacity during long-term cultivation conditions. However, the contents and the proportions of the main alkaloids galanthamine (Gal) and lycorine (Lyc) depended on the culture genotype and were distinguished for their fluctuations in the course of time. Addition of the precursors tyrosine and phenylalanine in the medium enhanced the biosynthetic activity: Gal of the best clone doubled its content reaching up to 1.94 mg/g DW, and Lyc was up to 5.68 mg/g DW which was several times more than the control. Most important for the success of the biosynthesis stimulation effect was the course of the alkaloid dynamics during the period of treatment.

In vitro clones of Leucojum aestivum cultured 4 years under equal conditions on agar MS medium su... more In vitro clones of Leucojum aestivum cultured 4 years under equal conditions on agar MS medium supplemented with BAP and NAA kept their inherent alkaloid profiles. However, the contents of the main alkaloids Gal and Lyc varied in the course of time.The dynamics were studied in 12 clones for at least 24 months (HPLC analysis every 3 months). Clones differed in the way of the changes of their alkaloid content. Different correlations were proved, using R, between the fluctuations of Gal, Lyc and cultures' dry matter of some clones and between clones.

IV Balkan Symposium on Vegetables and Potatoes, 2009

ABSTRACT Export Date: 18 October 2014

Biotechnology & Biotechnological Equipment, 1993

ABSTRACT The purpose of this study is to obtain a comparative assessment of dihaploide lines and ... more ABSTRACT The purpose of this study is to obtain a comparative assessment of dihaploide lines and oriental tobacco varieties for number of genetic parameters applying the combinatory approach to diallel analysis. Two basic morphological traits “plant height” and “leaf number” are investigated. The conclusions valid for both the dihaploid varieties and dihaploid lines are that dominance is the basic inheritance type of the traits and the dihaploid lines arc more stable in some aspects.

Biotechnology & Biotechnological Equipment

The influence of variable concentrations of the nutritive components of Gauze 1 medium on the β-l... more The influence of variable concentrations of the nutritive components of Gauze 1 medium on the β-lactamase synthesis by Streptomyces galbus (F) subsp. achromogenes—p154–59 has been studied. Twelve carbon, ten nitrogen, and four phosphate sources have been examined and the data has been used for carrying out Complete Factor Experiment (CFE 23). As a result of our experiments a complete optimisation of the fermentation medium has been obtained which enhances ten-fold β-lactamase synthesis by Streptomyces galbus.

Comptes rendus de l'Académie bulgare des sciences: sciences mathématiques et naturelles

Directly regenerated shoot-clumps of Leucojum aestivum manifested high biosynthetic capacity duri... more Directly regenerated shoot-clumps of Leucojum aestivum manifested high biosynthetic capacity during long-term cultivation conditions. However, the contents and the proportions of the main alkaloids galanthamine (Gal) and lycorine (Lyc) depended on the culture genotype and were distinguished for their fluctuations in the course of time. Addition of the precursors tyrosine and phenylalanine in the medium enhanced the biosynthetic activity: Gal of the best clone doubled its content reaching up to 1.94 mg/g DW, and Lyc was up to 5.68 mg/g DW which was several times more than the control. Most important for the success of the biosynthesis stimulation effect was the course of the alkaloid dynamics during the period of treatment.

In vitro clones of Leucojum aestivum cultured 4 years under equal conditions on agar MS medium su... more In vitro clones of Leucojum aestivum cultured 4 years under equal conditions on agar MS medium supplemented with BAP and NAA kept their inherent alkaloid profiles. However, the contents of the main alkaloids Gal and Lyc varied in the course of time.The dynamics were studied in 12 clones for at least 24 months (HPLC analysis every 3 months). Clones differed in the way of the changes of their alkaloid content. Different correlations were proved, using R, between the fluctuations of Gal, Lyc and cultures' dry matter of some clones and between clones.

Seed Science and Technology, 2012

ABSTRACT The effect of three mutated genes affecting anthocyanin biosynthesis in tomato (anthocya... more ABSTRACT The effect of three mutated genes affecting anthocyanin biosynthesis in tomato (anthocyaninless of Hoffmann - ah, anthocyaninwithout - aw and baby lea syndrome - bls) on germination capacity of the brown seed (bs) mutant was investigated. Mutations brown seed ( bs, bs 2, bs 4) controlling darkness of the seed testa are known to have a negative impact on the velocity of seed germination. In contrast, the three anthocyaninless mutants, characterised by absence of condensed tannins in the testa inner epidermal layer were found to enhance germination under optimal and stress conditions. The study was performed on a series of isogenic/near isogenic lines (IL/NILs) as follows: Ailsa Craig (AC), AC bs, AC ah, AC aw, AC bls, AC ah bs, AC aw bs and AC bls bs. Under optimal conditions, low temperature and salt stress, the anthocyaninless IL/NILs possessing brown seeds germinated more rapidly than the seeds of the anthocyanin-containing bs line (AC bs), the differences in time to 50% germination being significant. The histochemical tests of the seed coat provided evidence that, as in ah, aw and bls mutants, no condensed tannins were detected in the testa of double-mutant seeds. We concluded that the absence of condensed tannins in the testa of the brown seeds contributed to their more rapid germination.

Seed Science and Technology, 2008

... Bulgarian Academy of Sciences, Department of Cytogenetics, Tzarigradsko chosse, 13 km., Sofia... more ... Bulgarian Academy of Sciences, Department of Cytogenetics, Tzarigradsko chosse, 13 km., Sofia 1113, Bulgaria 3 University of Sofia, “St. Kl. ... that might contribute to their increased moisture uptake during storage, determined by Villers and Edgcumbe (1975) as a factor causing ...

Biotechnology & Biotechnological Equipment, 2014

Genetic variability in modern crops is limited due to domestication and selection processes. Gene... more Genetic variability in modern crops is limited due to domestication and selection processes. Genetic variation in eight Bulgarian tomato varieties and breeding lines (variety Plovdivska karotina, variety IZK Alya, L21b, L53b, L1140, L1116, L975, L984) differing in their morphological and biochemical composition was assessed using a highly efficient and lowcost fluorescent simple sequence repeat (SSR) genotyping platform. Genotyping was conducted with 165 publicly available microsatellite markers developed from different research groups under a number of projects in tomato (SOL Genomics SSRs, Kazusa TGS and TES, SLM, TMS and LEMDDNa) among which only five (3.03%) failed to amplify the expected PCR fragments. Of the remaining markers, 81 (50.62%) were polymorphic in the whole collection of eight genotypes. Among the marker groups used, SLM markers were most polymorphic, followed by TMS and SOL Genomics SSR markers. The total number of amplified alleles was 299, with a mean of 1.869; and the average polymorphic information content (PIC) was 0.196. The genetic diversity within the collection was relatively low (0.2222). Nei's genetic distance varied from 0.0953 to 0.3992. Cluster analysis using the un-weighted pair group method with arithmetic mean (UPGMA) method indicated that the studied tomato genotypes are grouped in four main clusters, which is to some extent consistent with the morpho-and hemo-types of the studied tomatoes. Variety IZK Alya (cherry type) and two of the breeding lines (L1140, L1116) formed three separate and more distant clusters. The fourth cluster includes the other five genotypes. The observed grouping of these genotypes in two sub-clusters reflects their similar morphological and biochemical composition. The genetic distance information from this study might be useful for further implementation of breeding strategies and crosses among these inbred lines.

Biotechnology & Bioindustry, 1988

Theoretical and Applied Genetics, 1982

A reconstructed karyotype of barley with all chromosomes interdistinguishable was treated with hy... more A reconstructed karyotype of barley with all chromosomes interdistinguishable was treated with hydroxyurea (HU) and Actinomycin D (Act D). The distribution pattern of chromatid aberrations after treatment with HU alone is characterized by a marked preferential involvement in chromatid translocations of segments 36 (NOR of satellite chromosome 6) and 43 (NOR of satellite chromosome 7). Act D applied at the low concentration of 0.05 ~g/ml (4.10 _8 M) before HU treatment, or combined with HU, was found to cause an apparent decrease of HU-induced aberration frequencies in NORs. The exchanges in both segments proved to be approximately a half lower after Act D application when compared to the respective controls (treatment with HU alone). A recovery period of 5 h between the prolonged pretreatment with Act D (15 h) and the HU treatment eliminated the effect of the drug. The possible dependence of mutation induction upon the transcriptional activity of rDNA in NORs after Act D application is discussed.

in Vitro Cellular & Developmental Biology-plant, 2009

The investigation deals with in vitro clonal propagation of L. aestivum L. (summer snowflake), a ... more The investigation deals with in vitro clonal propagation of L. aestivum L. (summer snowflake), a threatened Amaryllidaceae plant species in Bulgaria used in the pharmaceutical industry as raw material for production of galanthamine-based medicines. Plants of known origin and with different alkaloid profile were taken from the living collection of the Institute of Botany, Sofia. Bulbs were used to initiate in vitro cultures and 24 clones were multiplied. The influence of the clone origin on the propagation coefficient, shoot and bulblet morphology, alkaloid profile and content of galanthamine, lycorine, and four related alkaloids was evaluated. Clones kept stable alkaloid profiles and for most of them, high regeneration rates were noted. Galanthamine content of some clones was commensurable with that of Bulgarian populations of L. aestivum of commercial importance. Five clones: four galanthamine-type and one lycorine-type were selected as promising for further investigation.

Biotechnology & Biotechnological Equipment, 2012

ABSTRACT Fragile X syndrome is a genetic neuro-developmental disorder, caused by the transcriptio... more ABSTRACT Fragile X syndrome is a genetic neuro-developmental disorder, caused by the transcriptional inactivation of the gene Fmr1(Fragile X mental retardation 1). The lack of its protein product (FMRP) is accompanied by defects in synaptic maturation and morphology and by synaptic dysfunction throughout the nervous system. FMRP is an RNA-binding protein, which interacts with specific neuronal mRNA-targets and with other proteins and is involved in mRNA-transport, stability and translation Drosophila model closely recapitulates the neuronal defects of the clinical disease phenotype and its FMRP homolog (dFMRP) shares similar biochemical features. Using this model and the GAL4/UAS system for targeted gene expression, we performed genetic interaction experiments. We over-expressed the gene dfmr1 (Drosophia fragile X mental retardation 1) in the developing wing imaginal discs and looked for possible suppressor/enhancer effects of the genes scrib(sribbled) and dlg1(discs large 1). We also looked for similar genetic interactions in the adult brain neurons. We found that scrib acted as an enhancer of the mutant wing phenotype, induced by the over-expression of dfmr1. scrib also enhanced the mutant synaptic phenotype in the adult brain neurons, caused by the overexpression or lack of expression of dfmr1. dlg1 had an opposite suppressor effect in both systems analyzed. It rescued the mutant wing phenotype and the mutant synaptic phenotype as well. Our results demonstrate that dfmr1 interacts genetically with the members of the Lgl-family of scaffolding proteins and functions with them in the synaptic architecture of Drosophila adult brain neurons.

Proceeding of the Bulgarian Academy of Sciences, 2013

Forage productivity and quality are the most significant traits of alfalfa (Medicago sativa L.). ... more Forage productivity and quality are the most significant traits of alfalfa (Medicago sativa L.). The objective of that study was to compare the photosynthetic properties of some trifoliolate and multifoliolate alfalfa genotypes. Plants were selected at the Institute of Agriculture and Seed Science "Obraztsov chiflik"-Ruse. MF23 multifoliolate alfalfa line and the two trifoliolate ones with high and low productivity and standard variety Prista 2 were investigated. The studied fluorescence parameters indicate the lack of differences between low and high yield alfalfa trifoliolate populations irrespective of their different productivity, while MF23 shows enhanced PSII down-regulation, which relates to a higher potential to adjust MF23 to environmental changes. Better adjustment to the environment is one of the factors that determine higher productivity of MF23 in comparison to multifoliolate alfalfa plants studied previously.

In Vitro Cellular & Developmental Biology - Plant, 2008

The investigation deals with in vitro clonal propagation of L. aestivum L. (Summer Snowflake), a ... more The investigation deals with in vitro clonal propagation of L. aestivum L. (Summer Snowflake), a threatened Amaryllidaceae plant species in Bulgaria used in the pharmaceutical industry as raw material for production of galanthamine-based medicines. Plants of known origin and with different alkaloid profile were taken from the living collection of the Institute of Botany, Sofia. Bulbs were used to initiate in vitro cultures and 24 clones were multiplied. The influence of the clone origin on the propagation coefficient, shoot and bulblet morphology, alkaloid profile and content of galanthamine, lycorine, and four related alkaloids was evaluated. Clones kept stable alkaloid profiles and for most of them, high regeneration rates were noted. Galanthamine content of some clones was commensurable with that of Bulgarian populations of L. aestivum of commercial importance. Five clones: four galanthamine-type and one lycorine-type were selected as promising for further investigation.

Engineering in Life Sciences, 2012

The results described in these studies proved that the successful in vitro bioproduction of galan... more The results described in these studies proved that the successful in vitro bioproduction of galanthamine from L. aestivum shoot-clumps required mainly the selection of in vitro clones with a genetically determined high ability to produce the desired alkaloids, although the expression of this ability could be additionally influenced by diverse exterior factors, such as some components of the nutrient medium, or the cultivation conditions of the ambience. Tissue differentiation was also of great importance for the biosynthetic capacity of the cultures. The most suitable inocula for in vitro biosynthesis of galanthamine in liquid medium were the directly regenerated shoot-clumps, ensuring high alkaloid concentrations between 1 and 2 mg/g DW for the selected clones. We observed astonishing clone-specific dynamics of the biosynthetic activity of all of the studied in vitro clones. The dynamics were obviously related to the strong biological clock of the species, persisting even in several-year old cultures. These dynamics did not coincide with those usual for the plants growing in situ and under controlled field conditions. In our opinion, the clone specificity of the biosynthetic dynamics could be due to the disturbance of the plant regulation mechanism under the equal conditions of the ambience in the culture room. The sharp decrease of the alkaloid concentrations were transient, followed by an increase, so that cultures were retaining their biosynthetic capacity. The biosynthesis of the main alkaloids, galanthamine and lycorine, was influenced by diverse stimulants such as substances causing stress (JA), feeding with alkaloid precursors (the amino acids phenylalanine and tyrosine, and CH), and physical treatment (acoustic waves). However, the course of the biosynthetic dynamics during the period of the treatments was always the most important factor for the success of secondary metabolism stimulation. As far as scaling-up of the in vitro biosynthesis of valuable compounds, a stable and predictable yield is required, and additional investigations aimed at the annulment of the effect plant biological clock on alkaloid biosynthesis are needed. The elucidation of the relative influences of the diverse factors modulating alkaloid biosynthesis was of great importance. The high galanthamine concentrations of the selected in vitro clones are a promising basis for future studies.

Biotechnology & Biotechnological Equipment, 2014

Genetic variability in modern crops is limited due to domestication and selection processes. Gene... more Genetic variability in modern crops is limited due to domestication and selection processes. Genetic variation in eight Bulgarian tomato varieties and breeding lines (variety Plovdivska karotina, variety IZK Alya, L21b, L53b, L1140, L1116, L975, L984) differing in their morphological and biochemical composition was assessed using a highly efficient and lowcost fluorescent simple sequence repeat (SSR) genotyping platform. Genotyping was conducted with 165 publicly available microsatellite markers developed from different research groups under a number of projects in tomato (SOL Genomics SSRs, Kazusa TGS and TES, SLM, TMS and LEMDDNa) among which only five (3.03%) failed to amplify the expected PCR fragments. Of the remaining markers, 81 (50.62%) were polymorphic in the whole collection of eight genotypes. Among the marker groups used, SLM markers were most polymorphic, followed by TMS and SOL Genomics SSR markers. The total number of amplified alleles was 299, with a mean of 1.869; and the average polymorphic information content (PIC) was 0.196. The genetic diversity within the collection was relatively low (0.2222). Nei's genetic distance varied from 0.0953 to 0.3992. Cluster analysis using the un-weighted pair group method with arithmetic mean (UPGMA) method indicated that the studied tomato genotypes are grouped in four main clusters, which is to some extent consistent with the morpho-and hemo-types of the studied tomatoes. Variety IZK Alya (cherry type) and two of the breeding lines (L1140, L1116) formed three separate and more distant clusters. The fourth cluster includes the other five genotypes. The observed grouping of these genotypes in two sub-clusters reflects their similar morphological and biochemical composition. The genetic distance information from this study might be useful for further implementation of breeding strategies and crosses among these inbred lines.

In Vitro Cellular & Developmental Biology - Plant, 2009

The investigation deals with in vitro clonal propagation of L. aestivum L. (Summer Snowflake), a ... more The investigation deals with in vitro clonal propagation of L. aestivum L. (Summer Snowflake), a threatened Amaryllidaceae plant species in Bulgaria used in the pharmaceutical industry as raw material for production of galanthamine-based medicines. Plants of known origin and with different alkaloid profile were taken from the living collection of the Institute of Botany, Sofia. Bulbs were used to initiate in vitro cultures and 24 clones were multiplied. The influence of the clone origin on the propagation coefficient, shoot and bulblet morphology, alkaloid profile and content of galanthamine, lycorine, and four related alkaloids was evaluated. Clones kept stable alkaloid profiles and for most of them, high regeneration rates were noted. Galanthamine content of some clones was commensurable with that of Bulgarian populations of L. aestivum of commercial importance. Five clones: four galanthamine-type and one lycorine-type were selected as promising for further investigation.

Comptes rendus de l'Académie bulgare des sciences: sciences mathématiques et naturelles

Directly regenerated shoot-clumps of Leucojum aestivum manifested high biosynthetic capacity duri... more Directly regenerated shoot-clumps of Leucojum aestivum manifested high biosynthetic capacity during long-term cultivation conditions. However, the contents and the proportions of the main alkaloids galanthamine (Gal) and lycorine (Lyc) depended on the culture genotype and were distinguished for their fluctuations in the course of time. Addition of the precursors tyrosine and phenylalanine in the medium enhanced the biosynthetic activity: Gal of the best clone doubled its content reaching up to 1.94 mg/g DW, and Lyc was up to 5.68 mg/g DW which was several times more than the control. Most important for the success of the biosynthesis stimulation effect was the course of the alkaloid dynamics during the period of treatment.

In vitro clones of Leucojum aestivum cultured 4 years under equal conditions on agar MS medium su... more In vitro clones of Leucojum aestivum cultured 4 years under equal conditions on agar MS medium supplemented with BAP and NAA kept their inherent alkaloid profiles. However, the contents of the main alkaloids Gal and Lyc varied in the course of time.The dynamics were studied in 12 clones for at least 24 months (HPLC analysis every 3 months). Clones differed in the way of the changes of their alkaloid content. Different correlations were proved, using R, between the fluctuations of Gal, Lyc and cultures' dry matter of some clones and between clones.

IV Balkan Symposium on Vegetables and Potatoes, 2009

ABSTRACT Export Date: 18 October 2014

Biotechnology & Biotechnological Equipment, 1993

ABSTRACT The purpose of this study is to obtain a comparative assessment of dihaploide lines and ... more ABSTRACT The purpose of this study is to obtain a comparative assessment of dihaploide lines and oriental tobacco varieties for number of genetic parameters applying the combinatory approach to diallel analysis. Two basic morphological traits “plant height” and “leaf number” are investigated. The conclusions valid for both the dihaploid varieties and dihaploid lines are that dominance is the basic inheritance type of the traits and the dihaploid lines arc more stable in some aspects.

Biotechnology & Biotechnological Equipment

The influence of variable concentrations of the nutritive components of Gauze 1 medium on the β-l... more The influence of variable concentrations of the nutritive components of Gauze 1 medium on the β-lactamase synthesis by Streptomyces galbus (F) subsp. achromogenes—p154–59 has been studied. Twelve carbon, ten nitrogen, and four phosphate sources have been examined and the data has been used for carrying out Complete Factor Experiment (CFE 23). As a result of our experiments a complete optimisation of the fermentation medium has been obtained which enhances ten-fold β-lactamase synthesis by Streptomyces galbus.

Comptes rendus de l'Académie bulgare des sciences: sciences mathématiques et naturelles

Directly regenerated shoot-clumps of Leucojum aestivum manifested high biosynthetic capacity duri... more Directly regenerated shoot-clumps of Leucojum aestivum manifested high biosynthetic capacity during long-term cultivation conditions. However, the contents and the proportions of the main alkaloids galanthamine (Gal) and lycorine (Lyc) depended on the culture genotype and were distinguished for their fluctuations in the course of time. Addition of the precursors tyrosine and phenylalanine in the medium enhanced the biosynthetic activity: Gal of the best clone doubled its content reaching up to 1.94 mg/g DW, and Lyc was up to 5.68 mg/g DW which was several times more than the control. Most important for the success of the biosynthesis stimulation effect was the course of the alkaloid dynamics during the period of treatment.

In vitro clones of Leucojum aestivum cultured 4 years under equal conditions on agar MS medium su... more In vitro clones of Leucojum aestivum cultured 4 years under equal conditions on agar MS medium supplemented with BAP and NAA kept their inherent alkaloid profiles. However, the contents of the main alkaloids Gal and Lyc varied in the course of time.The dynamics were studied in 12 clones for at least 24 months (HPLC analysis every 3 months). Clones differed in the way of the changes of their alkaloid content. Different correlations were proved, using R, between the fluctuations of Gal, Lyc and cultures' dry matter of some clones and between clones.

Seed Science and Technology, 2012

ABSTRACT The effect of three mutated genes affecting anthocyanin biosynthesis in tomato (anthocya... more ABSTRACT The effect of three mutated genes affecting anthocyanin biosynthesis in tomato (anthocyaninless of Hoffmann - ah, anthocyaninwithout - aw and baby lea syndrome - bls) on germination capacity of the brown seed (bs) mutant was investigated. Mutations brown seed ( bs, bs 2, bs 4) controlling darkness of the seed testa are known to have a negative impact on the velocity of seed germination. In contrast, the three anthocyaninless mutants, characterised by absence of condensed tannins in the testa inner epidermal layer were found to enhance germination under optimal and stress conditions. The study was performed on a series of isogenic/near isogenic lines (IL/NILs) as follows: Ailsa Craig (AC), AC bs, AC ah, AC aw, AC bls, AC ah bs, AC aw bs and AC bls bs. Under optimal conditions, low temperature and salt stress, the anthocyaninless IL/NILs possessing brown seeds germinated more rapidly than the seeds of the anthocyanin-containing bs line (AC bs), the differences in time to 50% germination being significant. The histochemical tests of the seed coat provided evidence that, as in ah, aw and bls mutants, no condensed tannins were detected in the testa of double-mutant seeds. We concluded that the absence of condensed tannins in the testa of the brown seeds contributed to their more rapid germination.

Seed Science and Technology, 2008

... Bulgarian Academy of Sciences, Department of Cytogenetics, Tzarigradsko chosse, 13 km., Sofia... more ... Bulgarian Academy of Sciences, Department of Cytogenetics, Tzarigradsko chosse, 13 km., Sofia 1113, Bulgaria 3 University of Sofia, “St. Kl. ... that might contribute to their increased moisture uptake during storage, determined by Villers and Edgcumbe (1975) as a factor causing ...

Biotechnology & Biotechnological Equipment, 2014

Genetic variability in modern crops is limited due to domestication and selection processes. Gene... more Genetic variability in modern crops is limited due to domestication and selection processes. Genetic variation in eight Bulgarian tomato varieties and breeding lines (variety Plovdivska karotina, variety IZK Alya, L21b, L53b, L1140, L1116, L975, L984) differing in their morphological and biochemical composition was assessed using a highly efficient and lowcost fluorescent simple sequence repeat (SSR) genotyping platform. Genotyping was conducted with 165 publicly available microsatellite markers developed from different research groups under a number of projects in tomato (SOL Genomics SSRs, Kazusa TGS and TES, SLM, TMS and LEMDDNa) among which only five (3.03%) failed to amplify the expected PCR fragments. Of the remaining markers, 81 (50.62%) were polymorphic in the whole collection of eight genotypes. Among the marker groups used, SLM markers were most polymorphic, followed by TMS and SOL Genomics SSR markers. The total number of amplified alleles was 299, with a mean of 1.869; and the average polymorphic information content (PIC) was 0.196. The genetic diversity within the collection was relatively low (0.2222). Nei's genetic distance varied from 0.0953 to 0.3992. Cluster analysis using the un-weighted pair group method with arithmetic mean (UPGMA) method indicated that the studied tomato genotypes are grouped in four main clusters, which is to some extent consistent with the morpho-and hemo-types of the studied tomatoes. Variety IZK Alya (cherry type) and two of the breeding lines (L1140, L1116) formed three separate and more distant clusters. The fourth cluster includes the other five genotypes. The observed grouping of these genotypes in two sub-clusters reflects their similar morphological and biochemical composition. The genetic distance information from this study might be useful for further implementation of breeding strategies and crosses among these inbred lines.

Biotechnology & Bioindustry, 1988

Theoretical and Applied Genetics, 1982

A reconstructed karyotype of barley with all chromosomes interdistinguishable was treated with hy... more A reconstructed karyotype of barley with all chromosomes interdistinguishable was treated with hydroxyurea (HU) and Actinomycin D (Act D). The distribution pattern of chromatid aberrations after treatment with HU alone is characterized by a marked preferential involvement in chromatid translocations of segments 36 (NOR of satellite chromosome 6) and 43 (NOR of satellite chromosome 7). Act D applied at the low concentration of 0.05 ~g/ml (4.10 _8 M) before HU treatment, or combined with HU, was found to cause an apparent decrease of HU-induced aberration frequencies in NORs. The exchanges in both segments proved to be approximately a half lower after Act D application when compared to the respective controls (treatment with HU alone). A recovery period of 5 h between the prolonged pretreatment with Act D (15 h) and the HU treatment eliminated the effect of the drug. The possible dependence of mutation induction upon the transcriptional activity of rDNA in NORs after Act D application is discussed.

in Vitro Cellular & Developmental Biology-plant, 2009

The investigation deals with in vitro clonal propagation of L. aestivum L. (summer snowflake), a ... more The investigation deals with in vitro clonal propagation of L. aestivum L. (summer snowflake), a threatened Amaryllidaceae plant species in Bulgaria used in the pharmaceutical industry as raw material for production of galanthamine-based medicines. Plants of known origin and with different alkaloid profile were taken from the living collection of the Institute of Botany, Sofia. Bulbs were used to initiate in vitro cultures and 24 clones were multiplied. The influence of the clone origin on the propagation coefficient, shoot and bulblet morphology, alkaloid profile and content of galanthamine, lycorine, and four related alkaloids was evaluated. Clones kept stable alkaloid profiles and for most of them, high regeneration rates were noted. Galanthamine content of some clones was commensurable with that of Bulgarian populations of L. aestivum of commercial importance. Five clones: four galanthamine-type and one lycorine-type were selected as promising for further investigation.

Biotechnology & Biotechnological Equipment, 2012

ABSTRACT Fragile X syndrome is a genetic neuro-developmental disorder, caused by the transcriptio... more ABSTRACT Fragile X syndrome is a genetic neuro-developmental disorder, caused by the transcriptional inactivation of the gene Fmr1(Fragile X mental retardation 1). The lack of its protein product (FMRP) is accompanied by defects in synaptic maturation and morphology and by synaptic dysfunction throughout the nervous system. FMRP is an RNA-binding protein, which interacts with specific neuronal mRNA-targets and with other proteins and is involved in mRNA-transport, stability and translation Drosophila model closely recapitulates the neuronal defects of the clinical disease phenotype and its FMRP homolog (dFMRP) shares similar biochemical features. Using this model and the GAL4/UAS system for targeted gene expression, we performed genetic interaction experiments. We over-expressed the gene dfmr1 (Drosophia fragile X mental retardation 1) in the developing wing imaginal discs and looked for possible suppressor/enhancer effects of the genes scrib(sribbled) and dlg1(discs large 1). We also looked for similar genetic interactions in the adult brain neurons. We found that scrib acted as an enhancer of the mutant wing phenotype, induced by the over-expression of dfmr1. scrib also enhanced the mutant synaptic phenotype in the adult brain neurons, caused by the overexpression or lack of expression of dfmr1. dlg1 had an opposite suppressor effect in both systems analyzed. It rescued the mutant wing phenotype and the mutant synaptic phenotype as well. Our results demonstrate that dfmr1 interacts genetically with the members of the Lgl-family of scaffolding proteins and functions with them in the synaptic architecture of Drosophila adult brain neurons.