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Stevia rebaudiana Bertoni is a plant species which is frequently used not only as a sweetener, but also for its antibacterial and antioxidant properties. Nowadays, there are a large number of studies on the antimicrobial and antioxidant activity of S. rebaudiana leaves, but there are almost no data about the antimicrobial and antioxidant potential of extracts from the other parts of S. rebaudiana. The aim of the present study is to provide data of the antibacterial and antioxidant potential of methanolic extracts from different parts of S. rebaudiana (flowers, leaves, stems, rhizomes, and tubers) cultivated in Bulgaria. Antibacterial activity of the extracts against Staphylococcus aureus, Bacillus cereus and Escherichia coli was evaluated by agar well diffusion method, rutin content - by HPLC method, total phenolic content and radical scavenging potential - by UV-Vis analysis. S. rebaudiana extracts demonstrated antibacterial activity mainly against S. aureus - flower extracts expressed the highest activity, followed by the leaf and stem extracts. Only flower and leaf extracts demonstrated very low antibacterial activity against B. cereus. S. rebaudiana extracts did not show any antibacterial activity against E. coli. Methanolic extracts of this plant are rich in antioxidants. The highest concentrations of rutin and total phenols were found in the rhizomes of the plants, followed by the leaves, tubers, flowers, and stems, which corresponded to the radical scavenging potential of the same plant part. Comparisons between Trolox equivalents and gallic acid equivalents in different parts of S. rebaudiana on one hand, and Trolox equivalents and rutin concentration on the other hand showed a positive dependence and high values of the Pearson correlation - 0.9612 and 0.9707, respectively. The most important part of S. rebaudiana with medicinal significance (the leaves) has both comparatively good antibacterial activity and high antioxidant content, although the flowers and rhizomes expressed higher antibacterial and antioxidant activity, respectively. The experimental results imply that the cultivation area and climatic conditions of Bulgaria are very suitable for cultivation of S. rebaudiana plants with high content of antioxidants.

Agroforestry is a traditional land use system that may represent the answer to many present and future environmental problems. However, many farmers who practice agroforestry do not identity it as agroforestry nor even accept such identification. So far, there is not an organized training method on agroforestry apart the Agrof MM method. The Agrof MM, "Agroforesterie – Formation - Mediterannee et Montagne", was a 3-year KA-2 ERASMUS+ educational project that aimed to i. Train between 130 and 150 agricultural professionals in Europe, ii. Improve and develop the education tools to enable agroforestry training to be sustainable, and, iii. Develop a unique agroforestry qualification program in each European country. It was coordinated by AgroSup Dijon, France. Thirteen partners from ten different countries participated in the program by contributing a wide range of knowledge, experiences and ideas. Within the framework of the Agrof MM project, European stakeholders were trained based on a general format (Core content) that differentiated based on the location. The training contained lectures, examples and a field trip.

The aim of this study was to establish whether the type of the agricultural system has any influence on the essential oil production and antioxidant activity of industrial cultivated Rosa damascena Mill. in the Rose valley, Bulgaria. Six private farms from Kazanlak (Rose) Valley, Southern Bulgaria were included in the study conducted in the period 2019–2020. The first three selected farms are designated within the conventional farming and the other three are certificated as organic farms. GC/FID and GC/MS analyses were performed; the contents of total polyphenols and flavonoids in the methanol extracts from rose petals were determined. Additionally, the antioxidant activity of rose extracts was evaluated by four reliable methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2´-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assays. The impact of the agricultural system on the essential oil composition and antioxidant activity was evaluated by ANOVA statistical analysis. The results obtained showed that organic farming produced essential oil with a higher linalool and geraniol content and lower β-citronellol + nerol concentrations than conventional farming. It was found that organic farming production demonstrated a better antioxidant activity evaluated by the three DPPH, ABTS, and CUPRAC methods according to the averaged data for two years, 806.82, 797.66 and 1534.40 mM TE/g dw versus 510.34, 521.94 and 917.48 mM TE/g dw for CF, respectively, with high statistical significance for the DPPH and ABTS analyses. Consequentially, the rose extracts from the organic farming accumulated more phenolic compounds that corresponded to the higher antioxidant potential of the organic roses.

We studied karyological and morphological variability of the only representative of the genus Petrosimonia (Amaranthaceae) in Bulgaria and evaluated the current state of its populations in the country. The results indicated that Bulgarian populations of Petrosimonia brachiata have a diploid chromosome number of 2n = 16. In the population from the Pomorie Lake, the karyotype consists of six pairs of metacentric and two pairs of sub-metacentric chromosomes. In the population from the Atanasovsko Lake, satellites were observed on one pair of sub-metacentric chromosomes. Statistical analysis demonstrated that the main source of phenotype variation in the species is within the populations. Vegetative traits are more variable than generative ones. No significant variability was found in the studied quantitative characteristics or pollen morphology. Given the biological type of the species (annual) and its limited distribution in Bulgaria, the status of the two populations of P. brachiata cannot be regarded as stable, and the danger of a potential threat to them in the future is a possibility not to be excluded.

The aim of the study is to establish the current distribution оf Balkan endemics Moehringia jankae Griseb. ex Janka and Moehringia grisebachii Janka in Bulgaria. The routing method was used. All areas which the species inhabit according to literary sources were visited. Established were 12 populations of M. jankae and 32 populations of M. grisebachii. All established populations of M. jankae were from the Eastern Balkan Range on the territory of Sinite Kamani Natural Park. Three of the registered populations of M. grisebachii were from North-Eastern Bulgaria (Shumen region, near village Madara). Thirteen were from Sredna Gora Mts (nine on the territory of village Rozovets, two between village Rozovets and Bratan peak, two on peak Orlite and one between peak Orlite and the megalith Popova turla, rock formation along the road from village Rozovets to the rock formation Pravite kamani, the rock formation Pravite kamani, rock formations west of the megalith Pravite kamani, and one above village Pesnopoy in the area Usoykata). Nineteen were from the Eastern Balkan Range on the territory of Sinite Kamani Natural Park. Each population was assessed and the factors with negative influence were indicated.

Soil fungi are key component of soil biota having an important role in many ecological processes. As pathogens, decomposers and plant mutualists they can affect plant and soil health in agro-ecosystems significantly. The impact of crop management practices on soil fungal communities is diverse and still poorly studied. The lack of knowledge is mainly related to their hidden life mode, high phenotypic diversity, the great heterogeneity of soil microhabitats, difficulty for culturing and species identification. Collecting data with high accuracy to detect effects relevant to ecosystem management is an ongoing challenge for soil ecological studies and biomonitoring. However, the combination of DNA-based identification methods and Next Generation Sequencing technology was recognized as a powerful tool to evaluate biodiversity in environmental samples, especially soil biodiversity. In the frame of the National Research Program "Healthy Foods for a Strong Bio-Economy and Quality of Life", soil microbiome diversity (fungi, prokaryotes and archaea) will be used as indicator for assessing soil and plant health, and ecosystem services in several agricultural ecosystems. Four crop types (apple, lavender, rose and pea) located in southern Bulgaria, and managed by conventional and organic farming have been selected. Two general objectives related to soil biodiversity study were envisaged: to examine the impact of cropping systems on microbiome structural and functional diversity, and to propose management measures and agronomic practices improving soil and plant health. to examine the impact of cropping systems on microbiome structural and functional diversity, and to propose management measures and agronomic practices improving soil and plant health. Here we present some preliminary results on soil fungal communities evaluated by using amplicon DNA sequencing of the internal transcribed spacer 2 (ITS2) rDNA region. Multiple core soil samples were collected from 18 sampling plots in June 2019. Fungal diversity and community structure were evaluated at different taxonomic levels. The most common and abundant taxa at all sites were Fusarium Link 1809, Solicoccozyma X.Z.Liu, F.Y.Bai, M.Groenew. & Boekhout 2015, Cladosporium Link 1816, Alternaria Nees ex Wallroth 1816, and Mortierella E.Coemans 1863. The multivariate statistics (PCA) comparing the overall microbial composition revealed loose clusters linked to crops and localities. The study provides a new comprehensive overview of soil fungal communities (composition and diversity) from Bulgarian agro-ecosystems using high-throughput DNA sequencing.

Four populations of Betonica bulgarica Degen et Neič. at Sinite Kamani Natural Park were morphologically tested. Intrapopulation and interpopulation variabilities were established. The rеlationship between morphological variability, number, area and ecological appurtenance of the studied populations were explored. The results demonstrated that the main source of phenotype variation is intrapopulation variability, mainly due to the age structure of populations. The most variable traits are height of stem and dimensions of leaves. The registered interpopulation variability was affected by the differences in altitude, soil type and differences in environmental conditions and soil properties. Indumentum and morphology of generative organs had taxonomic significance for distinguishing B. bulgarica from the other species in the genus, including the species that were morphologically most similar to it - Betonica officinalis L.

Introduction. The condition of the vegetation cover can be traced from Space. Aim of the research. To assess the condition of the vegetation cover in Bulgaria during the last twenty years – its distribution over the country, its change in connection with the typical climatic changes, its seasonal change. Material and methods. The vegetation index NDVI according to NASA data was used to analyze the condition of the vegetation cover in Bulgaria for the years 2000-2020. The methods used were: seasonal data decomposition, t-test, GIS methods for spatial representation of data, Fourier analysis. Conclusions. 1. During the summer months the vegetation in the eastern parts of the territory of Bulgaria is noticeably weaker than in the western parts. The influencing factors-drought and frequent fires are probably related to global warming. 2. For the territory of Bulgaria there is a seasonal rotation of the horizontal gradient of the vegetation index in a counterclockwise direction-from east to west in summer, from northeast to southwest in autumn and from north to south in winter. 3. There is a winter increase in vegetation for Northern Bulgaria and to the greatest extent for Northeastern Bulgaria, as well as for Southwestern Bulgaria. Together with the decreasing snow cover, the winter vegetation contributes to the drought in the eastern parts of the country.

The study is conducted at the experimental base of Department of Plant productionat Trakia University, Stara Zagora. Triticale is grown after five predecessors anddifferent nitrogen fertilization rates. The predecessors are wintering peas, springpeas, sunflower, common wheat and triticale. Nitrogen fertilization rates are 0 (N0),40 (N40), 80 (N80), 120 (N120) kg ha-1 after legumes and 0 (N0), 60 (N60), 120 (N120),180 (N180) kg ha-1 after the other predecessors. The influence of the predecessorsand nitrogen fertilization on the nitrogen uptake, assimilated nitrogen fromfertilization, nitrogen utilization and nitrogen required for 100 kg produce oftriticale is established. Nitrogen assimilation from fertilization increases with theincrease of the nitrogen fertilizer rates. With the obtained yield from triticale anaverage of 96.53 kg ha-1 N is extracted from the soil with the grain, 18.97 kg ha-1 Nwith the straw or a total of 115.50 kg ha-1 N. When growing triticale afterleguminous predecessors the utilization of nitrogen is 35.39% and afterpredecessors sunflower, wheat and triticale - 28.76%. Nitrogen required for 100 kgyield of grain of triticale is 1.9 kg of nitrogen when growing after legumepredecessors and 2.8 kg of nitrogen after the other predecessors.

The aim of the study is to establish the current distribution оf Moehringia jankae Griseb. ex Janka and Moehringia grisebachii Janka in Sinite Kamani Natural Park and to assess the state of its populations. Nine populations of M. jankae and fourteen populations of M. grisebachii were registered. It has been established that the Balkan endemic M. jankae inhabits quartz porphyry rock formations, conglomerates and limestones in Karandila, Haidushka pateka, Kaloyanovi kuli, Kamilata areas at an altitude of 590 to 972 m. Its populations number from 10 to 72 specimens at an area of 0.5 to 796 m 2 . The Balkan endemic M. grisebachii inhabits quartz porphyry rock formations and conglomerates in Haidushka pateka, Mollova kuria, Kaloyanovi kuli, Karandila, Gornaka, Karakyutyuk, Kamilata and Golyama Chatalka at an altitude from 641 to 1049 m. Its populations number from 11 to about 347 specimens on an area of 1.7 to 1720 m 2 . Main threats to the populations of both species in the Natural Park are anthropogenic impact and adverse weather conditions during fruiting.

The karyological and morphological variability of species from the genus Dysphania were studied. The results demonstrated that genus Dysphania is represented in Bulgaria by five species: Dysphania ambrosioides, D. multifida, D. botrys, D. schraderiana and D. pumilio. The first two species are tetraploids with chromosome number 2n = 32 for D. ambrosioides and 2n = 36 for D. multifida. The remaining three species are diploids with 2n = 18. The results from statistical analysis demonstrated that the main source of phenotype variation in the species is the interpopulation variation. The specific characters which allowed their recognition are themorphological characteristics of the perianth lobes, the upper leaves and the seeds. The distinction between D. multifida, D. ambrosioides and D. schraderiana is based on differences in the quantitative traits, while in D. botrys and D. pumilio qualitative traits are also important. The basic evolutionary mechanisms are polyploidy and diploidy.Atendency towards reduction in the size of generative organs and the number of perianth lobes was found.