Tzenka Radoukova

Plovdiv University "Paisii Hilendarski" · Department of Botany and Biology for Teachers

Pinus heldreichii and P. peuce are Balkan endemics, Tertiary relicts, while Pinus mugo is an edificator in the phytocenoses in the Alpine mountain range. The chemical profile and essential oil (EO) yield and composition of these three species as a function of distillation time (DT) was the subject of this study. The working hypothesis was that EO o...

Plant essential oils (EOs) are often used as ingredients in the development of new biopesticides. The objective of this study was to investigate the allelopathic effects of three EOs of two juniper species against weed seeds. The EOs were extracted from Juniperus sabina L. Male (M) and Female (F) and J. excelsa Bieb. by means of steam distillation...

The objective of this study was to assess the biological activity of essential oils (EOs) of four Juniperus species obtained via two different distillation methods and their potential as biopesticides. The studied factors were juniper species (Juniperus communis L., J. oxycedrus L., J. pygmaea C. Koch., and J. sibirica Burgsd), plant sex (male (M)...

Juniperus excelsa M. Bieb and J. sabina L. contain essential oil (EO), while J. sabina also contains podophyllotoxin, which is used as a precursor for anti-cancer drugs. Two studies were conducted. The first assessed the variability in the EO profile and podophyllotoxin concentration of the two junipers, depending on the location and tree gender. T...

Grecian juniper (Juniperus excelsa M. Bieb.) is an evergreen tree and a rare plant found in very few locations in southern Bulgaria. The aim of this study was to evaluate the phytochemical content and antioxidant potential of J. excelsa unripe and ripe galbuli from three different locations in Bulgaria. The essential oil content ranged between 1.9%...

The chemical profile and antioxidant capacity of Juniperus virginiana, J. excelsa, and J. sabina essential oil (EO) fractions as a function of time was the subject of this study. The hypothesis was that, capturing EO in sequential timeframes during hydrodistillation would generate fractions containing unique compositions and antioxidant capacity. I...

The new trends in heritability behaviour, the coefficient of heritability, the selection coefficient, the number of genes and transgression and heterosis manifestation were determined, with regard to the number and size of leaves in Burley tobacco samples. P 1 , P 2 , F 1 and F 2 generations of seven new hybrid combinationswerestudied forthe purpos...

The floristic composition of vascular plants of three moisture zones, along the river Maritsa-"Rice-field Plovdiv", protected zone (PZ) "Rice-field Tsalapitsa" and protected area (PA) "Martvitsata Zlato Pole", was described in terms of phytogeographic elements, biological spectrum, conservation value and anthropogenic impact. The predominant floris...

To respond to the market demand for consistency of supply and quality, there are current efforts to develop junipers as agricultural crop for the production of juniper galbuli (berries). However, comparative data on the galbuli essential oil (EO) composition and bioactivity of different juniper species is limited. The objective of this study was to...

Juniperus communis L. is one of the widest spread species on earth, while J. pygmaea C. Koch. and J. sibirica Burgsd. are taxonomically controversial with some authors and the official Flora of Bulgaria recognizing them as separate species and other authors considering them sub-species of J. communis. There are current efforts on developing J. comm...

Juniperus communis L. is one of the widest spread species on earth, while J. pygmaea C. Koch. and J. sibirica Burgsd. are taxonomically controversial with some authors and the official Flora of Bulgaria recognizing them as separate species and other authors considering them sub-species of J. communis. There are current efforts on developing J. comm...

The biological indicators of ten Bulgarian and introduced Burley tobacco varieties were analyzed. The analysis showed that the expression of the biological indicators is closely related to the genotype and is insignificantly influenced by the environmental conditions. The most favorable results for all morphological features and the length of the v...

Morchella esculenta (L.) Pers. (morel) is one of the most widely appreciated wild edible mushrooms. The mushroom Morchella esculenta has long been known for its medicinal properties, especially its health-promoting effects, including antioxidant activity, hepatoprotective activity, antimicrobial properties and antitumor effect. Morchella esculenta...

Junipers (Juniperus spp.) are some of the most widespread species in the world with a wide ecological adaptation. Juniper galbuli (cones or berries) and their extracts have extensive applications in pharmaceuticals, perfumery, aromatherapy, alcoholic beverages, and cooking. The objective of this study was to evaluate EO composition, antimicrobial a...

The object of the study was to investigate the natural habitats in the forest-free zone of Malusha Peak, located on the main watershed ridge of the Shipka part of the Central Balkan Mountain range, part of the protected area (PA) "Bulgarka" BG0000399 and PA "Central Balkan-Buffer" BG0001493. According to the EUNIS classification used for making the...

This study reports data on the diversity of bryophytes in the Bulgarka Nature Park. The registered 55 species belonged to 23 families and 46 genera. Six species were with conservation status; 2 were assessed as Not Evaluated. The main threats were assessed and measures towards bryophyte conservation were proposed.

The comparative analysis on the inheritance parameters (inheritability coefficient, expressions of heterosis and transgression) are made. There are investigate the width of the leves in two populations and two generation of seven hybrid combination on local and introduced varieties tobacco Burley and Virginia. The results showed that in a hybrid co...

Examined are the biological and economic parameters of seven newly created lines of burley tobacco. Research results show that with the best biological assessment presents Line 1468, followed by a line 1472. Line 1468 gives the highest yield per hectare as an average over the period of study and three years of study. It also exhibited stability in...

Compares are the character of inheritance, inheritability coefficient, and expressions of heterosis and transgression referring to the length of the leves in Burley tobacco and Virginia tobacco. For this purpose, were investigated populations of Р 1 , Р 2 , F 1 and F 2 of seven hybrids Burley tobacco and seven hybrids Virginia tobacco, involving lo...

Correlations between the climatic characteristics: average daily temperature and precipitation sum, on the one hand, and, the biological, economic and chemical characteristics of ten large-leaved Burley and Virginia tobacco samples, on the other, were studied and compared. Except for the vegetation period length, for which a positive correlation wa...

The reaction of the cover tissue of leaves from Fraxinus americana L. and Fr. рensylvanica toward the impact of pollutants from the intensive public transport in Plovdiv has been determined. The comparative analysis between the form and the number of the basic epidermal cells and the size and number of stomata has been carried out by samples put un...

Data on the species composition, distribution and the ecological-trophic structure of larger fungi in Chivira Protected Area, Mt Sredna Gora floristic region are published for the first time. As a result of field and laboratory studies, 118 taxa belonging to Pezizomycota (9 species) and Agaricomycota (103 species and 5 varieties) were identified. A...

We specified the moments of occurrence of basic phases in growth of four species of wheatgrassses - Agrostis capillaries L., Festuca rubra L., Larchenfeldia flexuosa (L.) Schur. and Nardus stricta L. on territory of the "Central Balkans" National Park. We drew a phonological spectrum of the plants depending on the particular climate. We fixed the o...

The composition of the vegetative communities over two zones of the alpine woodless part of the Central Balkan Mountain has been examined. The description of the varieties has been realized in experimental areas with size 16 m2, chosen according to the different abundance of Juniperus sibirica Burgsd. - from 0 to 100%. The analysis carried out show...