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The objective of this study was to investigate the possibility of using microbial strains as residue decomposers and to determine the effect of these strains on chemical and microbial properties in the residue-amended soil. Greenhouse experiment consisted of eight Bacillus treatments, three Trichoderma treatments, and their combination, all applied to non-sterile chernozem soil amended with wheat straw. Incorporation of wheat straw improved soil chemical and microbial properties, while the extent of residue decom­position under microbial strains was intensified. Microbial treatments significantly affected the soil pH, the content of carbonate, total carbon, soil organic carbon, humus, and available phosphorus and potassium. Bacterial and fungal treatments also significantly influenced the total microbial number, ammonifiers, N2-fixers, fungi, actinomycetes, oligotrophs, copiotrophs, and cellulolytic microorganisms. The effect of microbial treatments varied depending on the applied strains and examined properties, with Bacillus strains being more promising residue decomposers compared to Trichoderma strains. The most effective microbial strains could be used as potential decomposers of crop residues.

Sunflower (Helianthus annuus L.) is one of the most important oil crops worldwide, including Serbia, where it is grown on about 200,000 ha with an average yield of 3 t/ha. Botrytis cinerea Pers. (1794) regularly occurs on sunflower seeds associated with the phenology of the host plant. However, sunflower seed is often affected by the Rhizopus spp., which causes similar symptoms on seed and seedlings as B. cinerea, and it is important to reliably differentiate those species based on morphological and molecular characteristics. The method used in this study for the detection of B. cinerea is described by ISTA method 7-003. The main task of this study was to isolate the causal agent of grey mould and rot of sunflower seed and seedlings. Infected seeds were covered with overgrown dark-grey mycelia with sporulation. In order to isolate the pathogen, the infected seed was transferred onto potato dextrose agar (PDA) and incubated for 7 days at 20°C. For morphological identification, 11 isolates were single-spored and subcultured onto PDA. Strains formed straight, noddy conidiophores, branched at the top and resembling a cluster with conidia. Conidia were ovoid or elliptical avg. 11.6 × 7.5 µm in size.

The aim of this study was to examine the effects of management practices and biofertilization on microbial activity in rhizosphere and yield of medicinal and aromatic plants. Field experiment was performed using four plant species: peppermint (Mentha x piperita L.), pot marigold (Calendula officinalis L.), sweet basil (Ocimum basilicum L.), and dill (Anethum graveolens L.). Treatments were arranged in a split-plot layout in four replicates using basic plots under conventional and organic management, and subplots with and without biofertilizer (Azotobacter chroococcum). Organic management positively affected the microbial number and activity. Biofertilization increased the total microbial number (13-21%), number of ammonifiers (13-60%), nitrogen-fixing bacteria (7-36%), actinomycetes (36-50%), fungi (60-100%), celluloly tic microorganisms (57-217%), dehydrogenase (28-52%) and beta-glucosidase activity (15-39%). The effects of management practices and biofertilization were highly significant for the yield of examined plants. The yields were higher on inoculated treatments both in conventional (5-26%) and organic (7-15%) growing system.

Plant growth promoting rhizobacteria (PGPR) enhance the plant growth directly by assisting in nutrient acquisition and modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens. The aim of this study was to select effective PGPR from a series of indigenous bacterial isolates by plant growth promotion and antifungal activity assays. This study confirmed that most of the isolates from maize rhizosphere were positive for PGPR properties by in vitro tests. Azotobacter and Bacillus isolates were better phosphate solubilizers and producers of lytic enzymes, hydrocyanic acid (HCN), and siderophores than Pseudomonas. Production of indole-3-acetic acid (IAA) and antifungal activity were the highest in Azotobacter, followed by Bacillus and Pseudomonas. The most effective Azotobacter isolates (Azt(3), Azt(6), Azt(12)) and Bacillus isolates (Bac(10,) Bac(16)) could be used as PGPR agents for improving maize productivity. Further selection of isolates will be necessary to determine their efficiency in different soils.

Clove rot caused by Fusarium spp. is a very important disease of common garlic (Allium sativum L.) occuring in many areas of the world. However, there is a lack of data about biocontrol of these pathogens. Bacillus species are attractive for research due to their potential use in the biological control of fungal diseases. The aim of this study was to select effective biocontrol agents from a series of indigenous Bacillus spp. isolated from soil. Bacterial isolates positive for hydrolytic enzymes production were screened for antifungal activity against Fusarium spp. isolated from infected garlic cloves. Polymerase chain reaction (PCR) analyses were used for molecular identification of bacterial (16S rDNA gene) and fungal (EF-1 alpha gene) isolates, and detection of biosynthetic genes for antimicrobial lipopeptides (surfactin, iturin, bacillomycin D and fengycin) in Bacillus spp. The obtained results confirmed the presence of Fusarium tricinctum, F. oxysporum f. sp. cepae, F. proliferatum, F. acuminatum and F. verticillioides as the causal agents of garlic clove rot. Four bacterial isolates identified as Bacillus subtilis exhibited the highest antagonistic effect during in vitro testing of antifungal activity (up to 71% reduction in fungal growth), and caused a significant suppression of garlic clove infection (up to 58% reduction in rot symptoms) in situ. Analysis of the antifungal compounds involved in the antagonistic activity of the examined isolates revealed their ability to produce the antibiotic lipopeptide surfactin. The most effective isolates of B. subtilis could be used as potential biocontrol agents of garlic clove rot.

The objective of this study was to assess the effect of biochar soil amendment (BSA) on chemical and microbial properties in different agricultural soils in Vojvodina Prov­ince. Short-term pot experiment consisted of five biochar application doses (0, 0.5, 1, 2, and 3%) and five contrasting soil types (Mollic Gleysol, Eutric Cambisol, Calcaric Fluvisol, Gleyic Chernozem, and Haplic Chernozem), planted with sunflower (Helianthus annuus L.) and winter wheat (Triticum aestivum L.). The examined chemical and microbial properties were significantly influenced by soil type and interaction of experimental factors. Significant influence of biochar on the contents of calcium carbonate (CaCO3), total nitrogen (N), total carbon (C), soil organic carbon (SOC), humus and potassium (K) of the tested soils was observed. Biochar also significantly affected the number of azotobacters (AZB), fungi (FNG), actino­mycetes (ACT) and copiotrophic bacteria (CB). The effect of BSA varied depending on the applied dose, with higher values of the examined chemical and microbial parameters at higher doses of application. Further studies on using biochar in soils with low fertility will be neces­sary to establish its efficiency as an enhancer for agricultural production in Serbia. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR31072]

The aim of the study was to examine the effects of management practice on microbial properties of soil under soybean production. The study included 180 samples of soil under certified organic soybean production and 80 samples in conventional production system. An abundance of the examined microbial groups was assessed using the indirect dilution method, followed by plating of soil suspension on different selective media, while dehydrogenase and β-glucosidase activity was measured spectrophotometrically. Our data indicated that the management practice affected the structure and activity of microbial com­munities. A significant positive effect of organic farming on Azotobacter spp., free N-fixers and abundance of actinomycetes was identified. The influence of management system for the total number of bacteria, ammonifiers and fungi was not observed. Significantly higher dehydrogenase and β-glucosidase activity was recorded in the soils under organic farming compared to the conventional farming. The obtained results showed an increase in organic matter content, associated with organic soil management, and its positive correlation with soil microbial properties. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 30122]

The objective of this study was to assess the effect of biochar soil amendment (BSA) on chemical and microbial properties in different agricultural soils in Vojvodina Prov­ince. Short-term pot experiment consisted of five biochar application doses (0, 0.5, 1, 2, and 3%) and five contrasting soil types (Mollic Gleysol, Eutric Cambisol, Calcaric Fluvisol, Gleyic Chernozem, and Haplic Chernozem), planted with sunflower (Helianthus annuus L.) and winter wheat (Triticum aestivum L.). The examined chemical and microbial properties were significantly influenced by soil type and interaction of experimental factors. Significant influence of biochar on the contents of calcium carbonate (CaCO3), total nitrogen (N), total carbon (C), soil organic carbon (SOC), humus and potassium (K) of the tested soils was observed. Biochar also significantly affected the number of azotobacters (AZB), fungi (FNG), actino­mycetes (ACT) and copiotrophic bacteria (CB). The effect of BSA varied depending on the applied dose, with higher values of the examined chemical and microbial parameters at higher doses of application. Further studies on using biochar in soils with low fertility will be neces­sary to establish its efficiency as an enhancer for agricultural production in Serbia.

Biocontrol using plant growth-promoting rhizobacteria (PGPR) represents an alternative approach to disease management, since PGPR are known to promote growth and reduce diseases in various crops. Among the different PGPR, members of the genus Bacillus are prefered for most biotechnological uses due to their capability to form extremely resistant spores and produce a wide variety of metabolites with antimicrobial activity. The objective of this research was to identify antagonistic bacteria for management of the plant diseases. Eleven isolates of Bacillus spp. were obtained from the soil samples collected from different localities in the Province of Vojvodina. The antifungal activity of bacterial isolates against five fungal species was examined using a dual plate assay. Bacillus isolates exhibited the highest antifungal activity against Fusarium proliferatum, Fusarium oxysporum f. sp. cepae and Alternaria padwickii, while they had the least antagonistic effect on Fusarium verticillioides and Fusarium graminearum. Molecular identification showed that effective bacterial isolates were identified as Bacillus safensis (B2), Bacillus pumilus (B3, B11), Bacillus subtilis (B5, B7) and Bacillus megaterium (B8, B9). The highest antagonistic activity was exhibited by isolates B5 (from 39% to 62% reduction in fungal growth) and B7 (from 40% to 71% reduction in fungal growth). These isolates of B. subtilis could be used as potential biocontrol agents of plant diseases., Biokontrola fitopatogena predstavlja alternativu primeni pesticida, s obzirom da bakterije označene terminom PGPR (Plant Growth Promoting Rhizobacteria) stimulišu biljni rast i štite biljke od bolesti. Zahvaljujući sposobnosti da formiraju veoma rezistentne endospore i produkuju širok spektar antimikrobnih supstanci, vrste roda Bacillus su veoma zastupljene u zemljištu i pogodne za primenu u biotehnologiji. Cilj istraživanja bio je da se utvrdi antifungalna aktivnost jedanaest Bacillus spp. izolata iz zemljišta s različitih lokaliteta u Vojvodini. Sposobnost bakterijskih izolata da inhibiraju rast pet izolata gljiva ispitana je metodom dvojne kultivacije. Izolati Bacillus spp. ispoljili su najveću antifungalnu aktivnost prema Fusarium proliferatum, Fusarium oxysporum f. sp. cepae, i Alternaria padwickii, dok je najmanji antagonistički efekat utvrđen prema Fusarium verticillioides i Fusarium graminearum. Efektivni izolati identifikovani su kao Bacillus safensis (B2), Bacillus pumilus (B3, B11), Bacillus subtilis (B5, B7) i Bacillus megaterium (B8, B9). Najveću antifungalnu aktivnost ispoljili su izolati B. subtilis B5 (39-62%) i B7 (40-71%). Ovi izolati mogu se koristiti kao potencijalni agensi za biološku kontrolu biljnih bolesti.

Mercury (Hg) is a heavy metal, designated as a pollutant in the environment, due to its harmful effects on biota. Mercury pollution is a significant global concern, not only due to its increased levels in the environment, but also due to its toxic effect on human health across the food chain. The aim of this study was to determine the content of Hg in agricultural soils and main field crops. Total number of 84 bulked soil samples were taken (0-30 cm depth) from agricultural land. At the same plots, 84 plant crops (11 species – used as food and feed) were taken during the vegetation season 2018. The samples were analyzed for total Hg content using Direct Mercury Analyzer DMA 80 Milestone. The obtained results of Hg content in soil were within interval 0.003-0.37 mg kg-1 . The average concentration of Hg was 0.08, with median 0.06±0.06 mg kg-1 . Obtained values of Hg in soils were below maximum allowable concentration (MAC) and this interval is complied with the most cited range in soils up to 1 mg kg-1 without known nearby contamination sources. It was found that Hg content is positively correlated with pH value, slit soil fraction, and CaCO3. The obtained results of Hg content in plant – field crops, were within interval 0.0001-0.9087 µg kg-1 . Obtained maximum value is still far lower than MACs for feed and food. According to the average Hg content in plant species, obtained results were classified from highest to lowest, respectively: bean, alfalfa, maize, soybean, rapeseed, sunflower, barley, pepper, wheat, rye and tomato.

Istraživanje je obuhvatilo utvrđivanje brojnosti pojedinih sistematskih i fizioloških grupa mikroorganizama, kao i određivanje aktivnosti enzima dehidrogenaze u zemljištima vinograda. Mikrobiološke karakteristike zavisile su od fizičkih i hemijskih osobina zemljišta na pojedinim parcelama. Najpovoljniji uslovi za razvoj i aktivnost mikroorganizama karakterisali su zemljišta neutralne i slabo alkalne reakcije, dok je najmanja brojnost većine mikroorganizama i enzimatska aktivnost zabeležena u kiselim zemljištima. Prisustvo lakopristupačnog bakra iznad 50 mg/kg zabeleženo je samo u 4% ispitivanih zemljišta, stoga dobijeni rezultati ne mogu potvrditi uticaj bakra na mikrobiološke karakteristike., The study included the determination of the abundance of specific systematic and physiological groups of microorganisms, as well as the determination of the activity of the enzyme dehydrogenase in vineyard soils. Microbiological characteristics depended on the physical and chemical properties of the soil in individual plots. The most favorable conditions for the development and activity of microorganisms were characterized by soils of neutral and slightly alkaline reactions, while the lowest abundance of most microorganisms and enzymatic activity was recorded in acidic soils. The presence of readily available copper above 50 mg / kg was recorded in only 4% of the tested soils, therefore the results obtained cannot confirm the influence of copper on microbial characteristics.

The performance of rhizobia in soybean nodules under drought stress conditions was analyzed using five Bradyrhizobium strains selected according to the osmotic stress tolerance in liquid medium. The effect of selected rhizobial strains on root and nodule antioxidant response and symbiotic performance was evaluated in a soil pot experiment under different levels of drought stress (0, 3, 5, 7 days withholding water). Drought stress increased the guaiacol peroxidase (POX) and ionically cell wall-bound peroxidase (POD) activity, antioxidant capacity, soluble protein content in roots and nodules, reduced the shoot dry weight (SDW), and increased the nitrogen content in the roots. Under water deficit conditions the highest increase of antioxidative parameters was recorded in the nodules of strain 216, and the lowest in roots and nodules of the plants inoculated with strain 511. Inoculation with strain 511 resulted in significantly lower SDW, root dry weight (RDW) and plant nitrogen content, while application of strain 216 resulted in the highest shoot attributes. Rep-PCR characterization and 16S-23S rDNA intergenic region sequencing emphasized the differences in strains genomic organization, especially for the 216 strain showing the higher tolerance to osmotic stress. The results implicate similarity between strain performance under osmotic stress in liquid medium and in symbiotic association under drought stress. The results also suggested important contribution of rhizobial strains in enhancing antioxidative response under drought stress and in symbiotic effectiveness, indicating more sensitive and tolerant symbioses.

Publikacija predstavlja nastavak istraživanja na temu karakterizacije zemljišta vinogradarskih geografskih proizvodnih područja u Republici Srbiji, ističući značaj zemljišta kao neraskidivu komponentu terroir-a. Poseban doprinos publikaciji čine poglavlja o glavnim aktuelnim karakteristikama terroir-a Pocersko-valjevskog rejona (geografski položaj, zastupljenost proizvođača i površine vinograda, klimatske i topografske karakteristike, sortiment, uzgojni oblici, starosna struktura vinograda i proizvodnja vina), uključujući istorijat vinogradarstva i vinarstva ovog područja.

A modern sustainable approach in agricultural practice would be a replacement of synthetic and toxic substances in the treatment of crop with benign and environmentally friendly compounds, by using principles of green chemistry. One of the possible directions could be using of ionic liquids (ILs), salts with melting points below 100 °C, which are well-known for manifesting antimicrobial activity. ILs can be used in the development of novel sources of antimicrobial agents such as antiseptics, biocides and antifungal agents. Furthermore, ILs have already been reported as alternative ‘green’ solvents for a wide range of reactions and technological processes. Considering the importance of research in the area of bioactivity of ILs for discovery of new green ILs for diff erent purposes, the aim of this study was to examine antifungal activity of nine newly synthesized ILs against phytopathogenic Alternaria strains isolated from from rice (A. padwickii), carrot (A. dauci) and linseed (A. linicola). Antifungal eff ect was estimated by micro-plate microdilution method for establishing minimum inhibitory (MIC) and minimum fungicidal concentration (MFC). All ionic liquids showed strain specifi c but good antifungal activity on Alternaria strains with MIC and MFC detected at the range from 9.23 mg/ml to 75.89 mg/ml. Only in case of the 1-(4-hydroxy-2-oxy)butyl -3-methylimidazolium chloride [OHC2OC2mIm][Cl], no antifungal eff ect on A. dauci were observed. Comparing to A. padwickii and A. dauci., A. linicola showed higher sensitivity to all tested ILs. Th e obtained results indicate the possibility of usage of ILs in biocontrol of plant diseases, representing their application in crop protection. However, further research is necessary in order to examine their toxicity and biodegradability in the environment.

Uprkos variranju osobina stumilsanja rasta biljaka (PGP) kod razliĉitih vrsta, većina bakterijskih sojeva koji ispoljavaju višestruka PGP svojstva moţe biti korisna u formulaciji novih inokulanata. Istraţivanje efektivnih sojeva, pre PGP karakterizacije, zahteva izolaciju i identifikaciju odgovarujućih vrsta bakterija koje stimulišu biljni rast (PGPB). Cilj ovih istraţivanja bio je izolacija i molekularna identifikacija PGPB. Bakterije iz roda Bradyrhizobium izolovane su iz korenskih kvrţica razliĉitih sorti soje. Bakterije koje pripadaju rodu Bacillus izolovane su iz rizosfernog, poljoprivrednog i nepoljoprivrednog zemljišta. Svi uzorci za izolaciju PGPB prikupljeni su s razliĉitih lokaliteta u Vojvodini. Karakterizacija izolata izvršena je na osnovu morfoloških i biohemijskih svojstava. Izolati koji su pokazali sliĉnost sa vrstama Bradyrhizobium sp. and Bacillus sp. bili su predmet molekularne karakterizacije. Nakon ekstrakcije DNK, parcijalna 16S rDNA genska sekvenca iz izolata je umnoţena PCR metodom upotrebom univerzalnih prajmera fD1 i rP3. Preĉišćavanje i sekvencioniranje umnoţenih fragmenata uraĊeno je u Macrogen, Juţna Koreja. Sekvence su analizirane pomoću programa FinchTV i izvršeno je višestruko poreĊenje dobijenih sekvenci sa postojećim sekvencama u NCBI GenBank bazi podataka. Svi izolati Bradyrhizobium identifikovani su kao B. japonicum. U okviru Bacillus izolata, identifikovano je devet razliĉitih vrsta (B. megaterium, B. cereus, B. pumilus, B. subtilis, B. thuringiensis, B. safensis, B. mycoides, Lysinibacillus fusiformis, and L. sphaericus). Nastavak karakterizacije ovih izolata preko PGP skrininga neophodan je za odabir potencijanlo efektivnih sojeva za inokulaciju u kontrolisanim i poljskim uslovima., Despite the variability within the plant growth promoting properties (PGP) in different species, most of bacterial strains that exhibit multiple PGP traits might be useful in formulating new inoculants. Search for effective strains, prior to PGP characterization, require isolation and identification of desirable species of plant growthpromoting bacteria (PGPB). The aim of this study was to isolate and identify PGPB on the basis of molecular characteristics. Bacteria of Bradyrhizobium genus were obtained from root nodules of different soybean cultivars. Bacteria belonging to genus Bacillus were isolated from different soil samples which included the rhizosphere of plants, agricultural and non-agricultural soils. All samples for PGPB isolation were collected from various parts of the Vojvodina Province. Characterization of isolates was performed according to morphological and biochemical properties. Isolates showing resemblance with Bradyrhizobium sp. and Bacillus sp. were subjected to molecular characterization. Following DNA extraction, a partial 16S rDNA gene sequence from the isolates was amplified by PCR using universal primers fD1 and rP3. Purification and sequencing of the amplified fragments were done in the Macrogen, South Korea. Sequences were analyzed using the program FinchTV and compared to sequences in NCBI GenBank for identification. All isolates of Bradyrhizobium were identified as B. japonicum. Within Bacillus isolates, nine different species (B. megaterium, B. cereus, B. pumilus, B. subtilis, B. thuringiensis, B. safensis, B. mycoides, Lysinibacillus fusiformis, and L. sphaericus) were identified. Further characterization of these isolates through PGP screening will be necessary to select potentially effective strains for inoculation assays in greenhouse and field.

Plant diseases caused by fungal pathogens can lead to major economic losses in agriculture. Th e genus Alternaria includes saprobic, endophytic and pathogenic species that may cause various plant diseases such as blight disease. Symptoms of Alternaria blight include the presence of irregular, oft en circular, brown to dark brown coloured leaf spots. Alternaria spp. also cause collar rots, stem lesions, tuber and fruit rots of their respective hosts. In addition, bacteria are one of the most frequently biocontrol agents used to protect plants from diseases. Bacillus species control disease through a variety of mechanisms. Bacterial antagonists might act as inhibitors of growth, development and reproduction of pathogen, or as inducers of host resistance in plant. Th e objective of this study was to examine in vitro antifungal activity of ten antagonistic Bacillus strains from collection of Department for Microbiology of Institute of Field and Vegetable Crops, Novi Sad. Strains were originally isolated from the soil samples collected from several localities of Vojvodina Province. Antifungal activity of Bacillus strains against Alternaria padwickii, A. dauci and A. linicola, obtained from rice, carrot and linseed, respectively was tested using a dual plate assay. Th e results confi rmed that all tested Bacillus strains showed antifungal acivity against Alternaria spp. Th e highest antagonistic activity was exhibited by B. pumilus B11 (45.71% to 51.25%), B. subtilis B13 (45.71% to 49.37%) and B. subtilis B32 (45.71% to 52.08%), while B. pumilus B23 had the weakest antifungal activity. B. safensis B2 (35.24% to 48.33%), B. pumilus B21 (40.95% to 48.75%) and B. pumilus B22 (33.50% to 49.17%) also demonstrated good antifungal potential. A. dauci was the most sensitive fungus, while the most resistant was A. linicola. Obtained results indicate the possibility of usage of the most eff ective Bacillus strains as potential biocontrol agents of plant diseases caused by Alternari

The aim of this study was to investigate the possibility of improving the microbiological fertilizer for soybean by co-inoculation with PGPR strains. Experiment was carried out under field conditions, on a chernozem soil, using soybean cultivar Galina and five inoculation treatments: B. japonicum; B. japonicum + A. chroococcum + humic acid; B. japonicum + A. chroococcum; B. japonicum + B. subtilis; B. japonicum + B. megaterium. Bacterial treatments had a positive effect on activity and number of investigated microbial groups in rhizosphere, nitrogen fixation parameters and yield of soybean. Inoculation, on average, increased the number of azotobacters, total microbial number, ammonifiers, N-fixing bacteria, actinomycetes, dehydrogenase activity, as well as the mass and number of nodules, nitrogen content in plants and seeds, number of poods and seeds, dry seed mass, and yield of soybean. Co-inoculation had a better effect on the number of microorganisms, dehydrogenase activity and yield of soybean, while the best effect on nitrogen fixation and yield parameters was achieved by single inoculation.

The study monitored microbial abundance and dehydrogenase activity in chernozem soil under different cropping systems. Soil samples were taken from the long-term trials Crop Rotations and IOSDV, at the Rimski Šančevi experimental field of the Institute of Field and Vegetable Crops. The soil samples were collected in two years from ten cropping systems at three sampling depths. Number of the examined microbial groups was assessed by the indirect dilution method, while dehydrogenase enzyme activity was measured spectrophotometrically. Number of the tested microbial groups and dehydrogenase activity varied significantly depending on the cropping system and year of study, while sampling depth significantly affected enzyme activity. The highest number of microorganisms was obtained in non-agricultural soil and unfertilized soil under 2-year and 3-year rotation, while the highest dehydrogenase activity was recorded in non-agricultural soil and soil under wheat grown in monoculture., Cilj ovih istraživanja bio je utvrđivanje mikrobiološke brojnosti i dehidrogenazne aktivnosti u černozemu u zavisnosti od sistema gajenja. Uzorci zemljišta su prikupljeni na višegodišnjim ogledima Plodoredi i IOSDV, na eksperimentalnom polju Rimski šančevi Instituta za ratarstvo i povrtarstvo. Zemljište je uzorkovano tokom dve godine iz deset sistema gajenja i tri dubine. Brojnost mikroorganizama utvrđena je indirektnom metodom razređenja, dok je aktivnost dehidrogenaze određena spektrofotometrijski. Brojnost ispitivanih grupa mikroorganizama i dehidrogenazna aktivnost značajno su varirali u zavisnosti od sistema gajenja i godine ispitivanja, dok je dubina uzorkovanja značajno uticala na aktivnost enzima. Najveća brojnost mikroorganizma utvrđena je u nepoljoprivrednom zemljištu i zemljištu pod neđubrenim dvopoljem i tropoljem, dok je najviša dehidrogenazna aktivnost zabeležena u nepoljoprivrednom zemljištu i zemljištu pod monokulturom pšenice.

Aim of the study was to examine the effects of soil use on soil microbial properties at five locations in Central Serbia. The study included 42 samples of soil under certified organic system, 8 samples under conventional system, and 30 samples of abandoned soils. The number of examined microbial groups was assessed using the indirect dilution method followed by plating of soil suspension on different selective media, while dehydrogenase activity was measured spectrophotometrically. The number and activity of microorganisms at the tested plots primarily depended on the soil pH. The acidic soil reaction caused more rapid fungal growth and lower presence of actinomycetes and Azotobacter sp. There were no significant alterations in the number of microorganisms, ammonifiers and fungi under the specific soil use system. Significantly higher dehydrogenase activity was recorded in the abandoned soils and soils under organic systems compared to the conventional farming., Cilj ovih istraživanja bio je da se ispita uticaj načina korišćenja zemljišta na mikrobiološka svojstva. Istraživanja su sprovedena u pet oblasti na teritoriji centralne Srbije. Analizirana su 42 uzorka zemljišta pod sertifikovanom organskom proizvodnjom, 8 uzoraka zemljišta u konvencionalnoj poljoprivrednoj proizvodnji i 30 uzoraka napuštenog zemljišta. Brojnost mikroorganizama određena je indirektnom metodom, zasejavanjem suspenzije zemljišta odgovarajućeg razređenja na selektivne hranljive podloge, dok je aktivnost enzima dehidrogenaze određena spektrofotometrijski. Na raznovrsnost, brojnost i aktivnost mikroorganizama na ispitivanim parcelama prvenstveno je uticala pH reakcija zemljišta. Kisela pH reakcija na većini ispitivanih lokaliteta uslovila je intenzivniji razvoj gljiva i manje prisustvo aktinomiceta i Azotobacter sp. Ukupan broj mikroorganizama, brojnost amonifikatora i gljiva nije se značajno menjao u zavisnosti od načina korišćenja parcele. Značajno viša prosečna aktivnost dehidrogenaze zabeležena je u napuštenim zemljištima i zemljištima u organskom sistemu gajenja u poređenju sa zemljištima u konvencionalnoj proizvodnji.

Ova publikacija predstavlja svojevrsno reizdanje prethodne publikacije na temu uređenja zemljišta pri podizanju vinograda, a koja je urađena na primeru Mlavskog vinogradarskog rejona. Publikacija je nastala sa željom da se istakne važnost svih potrebnih mera uređenja zemljišta uz planski pristup pri zasnivanju vinograda široj publici i na osnovu velikog interesovanja proizvođača za prethodno izdanje. Prvi deo publikacije sadrži opis svih potrebnih mera uz dopunjen i poboljšan, sistematizovani pristup. Prikazani konkretni rezultati u drugom delu publikacije su rezultat opsežnih istraživanja u okviru Projekta pod nazivom: „Uređenje poljoprivrednog zemljišta pri zasnivanju vinograda u Vranjskom rejonu“.

The aim of this study was to compare abundance of microorganisms in the rhizosphere of maize and soybean grown under conventional and organic management. The trial was set up on the chernozem soil at the experimental field of Bački Petrovac, Institute of Field and Vegetable Crops, Novi Sad. Rhizosphere samples were collected in two sampling terms during 2014 (July 7 and August 14) and analysed by the indirect dilution method followed by plating of soil suspension on selective nutritive mediums: soil agar for the total number of microorganisms, meat peptone agar for the number of ammonifiers, Waksman-Carey medium for the number of cellulolytic microorganisms, synthetic medium for the number of actinomycetes, Czapek Dox agar for the number of fungi, and N-free medium for the number of azotobacters and free N-fixers. The results showed significant differences in microbial abundance between plant species, growing systems and sampling terms. Significantly higher number of microorganisms was found in rhizosphere of soybean compared to maize, as well as in organic growing system compared to conventional. Significant differences between sampling terms were recorded for the number of ammonifiers, azotobacters, fungi and actinomycetes, while the number of most tested microbial groups was higher in the second sampling term.

Among 50 bacterial isolates obtained from maize rhizosphere, 13 isolates belonged to the genus Azotobacter. Isolates were biochemically characterized and estimated for pH and halo tolerance ability and antibiotic resistance. According to characterization, the six representative isolates were selected and further screened in vitro for plant growth promoting properties: production of indole-3-acetic acid (IAA), siderophores, hydrogen cyanide (HCN), exopolysaccharides, phosphate solubilization and antifungal activity (vs. Helminthosporium sp., Macrophomina sp., Fusarium sp.). Beside HCN production, PGP properties were detected for all isolates except Azt 7 . All isolates produced IAA in the medium without L-tryptophan and the amount of produced IAA increased with concentration of precursor in medium. The highest amount of IAA was produced by isolates Azt 4 (37.69 and 45.86 µg ml -1 ) and Azt 5 (29.44 and 50.38 µg ml -1 ) in the medium with addition of L-tryptophan (2.5 and 5 mM). The isolates showed the highest antifungal activity against Helminthosporium sp. and the smallest antagonistic effect on Macrophomina sp. Radial Growth Inhibition (RGI) obtained by the confrontation of isolates with tested phytopathogenic fungi, ranged from 10 to 48%., Među 50 izolata bakterija iz rizosfere kukuruza, 13 izolata pripadali su rodu Azotobacter. Izolati su biohemijski karakterisani i ispitana je tolerantnost prema reakciji sredine, koncentraciji soli i rezistentnost na antibiotike. Nakon karakterizacije, odabrano je šest reprezentativnih izolata za dalja ispitivanja PGP svojstava: produkcije indol-3-sirćetne kiseline (IAA), siderofora, cijanovodonične kiseline, egzopolisaharida, fosfosolubilizacije i antifungalne aktivnosti (prema Helminthosporium sp., Macrophomina sp., Fusarium sp.). Osim produkcije HCN, PGP svojstva utvrđena su za sve izolate osim Azt 7 . Najveću količinu IAA produkovali su izolati Azt 4 (37,69 i 45,86 µg ml -1 ) i Azt 5 (29,44 i 50,38 µg ml -1 ) u podlozi sa dodatkom L-tryptophan-a (2,5 i 5 mM). Izolati su ispoljili najveću antifungalnu aktivnost prema Helminthosporium sp., a najmanji antagonostički efekat prema Macrophomina sp. Procenat inhibicije rasta (RGI) dobijen suočavanjem izolata sa ispitivanim fitopatogenim gljivama kretao se od 10 do 48%.

Korisni mikroorganizmi ili mikroorganizmi promotori biljnog rasta (PGPM) ispoljavaju efekat na rast i razviće biljaka azotofiksacijom, mobilizacijom hraniva (N, P, Fe) u zemljištu i produkcijom fitohormona te na taj način stimulišu rast biljaka, povećavaju prinos i štite biljke od patogena. Cilj ovih istraživanja bio je da se izvrši karakterizacija bakterija izolovanih iz rizosfere kukuruza, inokulacija semena kukuruza odabranim izolatima, ispitivanje efektivnosti primene pojedinačnih i združenih kultura izolata na mikrobiološku aktivnost u rizosfernom zemljištu, kao i na početni rast i razvoj biljke, sadržaj pojedinih hranljivih elemenata u biljnom materijalu i prinos kukuruza. Korišćeno je 50 izolata iz rizosfernog zemljišta hibrida kukuruza NS 6010 gajenog na zemljištu tipa karbonatni černozem (13 izolata roda Azotobacter, 16 izolata roda Bacillus, 15 izolata roda Pseudomonas, 6 izolata roda Streptomyces). Karakterizacija izolata obuhvatila je određivanje morfoloških, fizioloških, biohemijskih i PGP osobina. Inokulacija semena kukuruza izvršena je s osam odabranih izolata primenjenih pojedinačno i u smeši i to s tri izolata azotobaktera (Azb5, Azb8, Azb13), s dva izolata bacilusa (Bac9, Bac15 ), s dva izolata pseudomonasa (Pse1, Pse5) i s jednim izolatom aktinomiceta (Act6). U ogledima su korišćeni hibridi kukuruza NS 6010 i NS 6030 selekcionisani u Odeljenju za kukuruz Instituta za ratarstvo i povrtarstvo, a efektivnost primene odabranih izolata na mikrobiološku aktivnost u rizosfernom zemljištu, kao i na biljku kukuruza, ispitana je u polukontrolisanim i poljskim uslovima. Brojnost mikroorganizama određena je metodom agarnih ploča, a dehidrogenazna aktivnost spektrofotometrijskom metodom. Uticaj izolata na klijanje semena ispitan je u laboratorijskim uslovima. Uticaj izolata na početni rast biljaka ispitan je u fazama 3. i 5-7. lista merenjem visine i suve mase nadzemnog dela biljke. Sadržaj azota, fosfora, bakra i cinka u biljnom materijalu (nadzemni deo/list), Beneficial or plant growth promoting microorganisms (PGPM) exert effect on plant growth and development through nitrogen fixation, mobilization of nutrients (N, P, Fe) in soil and production of phytohormones and thereby stimulate plant growth, increase yield and reduce pathogen infection. The aim of this study was to perform characterization of bacteria isolated from maize rhizosphere, inoculation of maize seeds with selected isolates, testing the effectiveness of single and co-inoculation on microbial activity in rhizosphere, as well as on initial growth and development of plants, content of some nutrients in plant material and yield of maize. 50 isolates from rhizosphere of maize hybrid NS 6010 grown on calcareous chernozem soil (13 isolates of the genus Azotobacter, 16 isolates of Bacillus, 15 isolates of Pseudomonas, 6 isolates of Streptomyces) were used. Characterization of isolates included determination of morphological, physiological, biochemical and PGP traits. Inoculation of maize seeds was carried out with eight selected strains applied individually and in mixture, and that with three isolates of Azotobacter (Azb5, Azb8, Azb13), two isolates of Bacillus (Bac9, Bac15), two isolates of Pseudomonas (Pse1, Pse5) and one isolate of Streptomyces (Act6). The experimental objects were maize hybrids NS 6010 and NS 6030 developed at Maize Department, Institute of Field and Vegetable Crops, and the effectiveness of selected isolates on microbial activity in rhizosphere, as well as on maize plant, was tested in semi-controlled and field conditions. The number of microorganisms was determined by agar plates method, and dehydrogenase activity by spectrophotometric method. Effect of isolates on maize seed germination was tested in the laboratory. The effect of isolates on initial plant growth was tested at 3 and 5-7 leaf stages by measuring height and dry weight of above ground plant parts. The contents of nitrogen, phosphorus, copper and zinc in plant material (above g

Garlic (Allium sativum L.) is considered to be one of the oldest crops in the world. During 2016, infected garlic bulbs occurred in storages on several localities of the Province of Vojvodina. Symptomatic cloves showed typical rot symptoms such as softened and spongy areas covered with white fungal growth with deep lesions formed on the cloves which became dry over time. A total of 36 isolates of Fusarium species were obtained from diseased cloves of garlic. Colony morphology and microscopic properties of isolated Fusarium species were recorded from the cultures grown on PDA and CLA, respectively. Identification of two chosen isolates was performed by sequencing the EF-1α gene. The TEF sequence of isolate JBL12 showed 100% similarity with several F. tricinctum sequences and sequence of JBL539 showed 99% identity with several F. acuminatum sequences and they were deposited in the NCBI GenBank. Based on the results of the morphological and molecular identification, isolates JBL12 and JBL539 were identified as F. tricinctum and F. acuminatum, respectively, as new causal agents of garlic bulbs rot in Serbia. Specific primers were designed for the PCR identification of the F. tricinctum., Beli luk (Allium sativum L.) smatra se jednom od najstarijih biljnih vrsta na svetu. Tokom 2016. godine, zapažena je pojava truleži belog luka u skladištima i magacinima na nekoliko lokaliteta u Vojvodini. Simptomi su se ispoljavali u vidu lezija, truleži belog luka kao i pojavom micelije na inficiranim čenovima. Cilj rada bio je izolacija i identifikacija Fusarium spp. na osnovu morfoloških i molekularnih karakteristika patogena. Izolacijom je dobijeno 36 izolata Fusarium spp. Detekcija i identifikacija odabranih izolata potvrđena je metodom PCR korišćenjem prajmera EF1 i EF2 koji amplifikuju proizvode veličine 700bp. U svim proučavanim izolatima formirani su amplikoni veličine 700bp. Izolacija DNK dva odabrana izolata izvršena je direktno iz micelije gljive (~100 mg), korišćenjem DNeasy Plant Mini Kit (Qiagen, Hilden, Germany). Identifikacija izolata JBL539 i JBL12 izvršena je sekvenciranjem EF-1α gena , koji su deponovani u NCBI bazu podataka pod brojem KX611146 (F. tricinctum) i KX752419 (F. acuminatum). Kreirani su specifični prajmeri za PCR identifikaciju vrste F. tricinctum.

Glavni cilj ove publikacije je da posluži kao vodič i priručnik svim proizvođačima za usvajanje planskog pristupa pri podizanju vinograda sa aspekta uređenja zemljišta. Obrađeni materijal u drugom delu ove publikacije, iznet je na osnovu sprovedenih opsežnih terenskih, pedoloških i laboratorijskih istraživanja, koja su obuhvatila četiri lokacije vinogradarskog rejona Mlava. 1. Planski pristup pri podizanju vinograda 2. Regulacioni radovi 3. Meliorativne mere đubrenja uz rigolovanje, popravka fizičkih osobina zemljišta i kalcizacija 4. Ostali aspekti pri zasnivanju vinograda 5. Primenjene metode istraživanja 6. Tipovi zemljišta 7. Fizička i vodno-fizička svojstva zemljišta 8. Plodnost, kalcizacija i preporuka za đubrenje 9. Sadržaj opasnih i štetnih materija 10. Mikrobiološka svojstva zemljišta Prilog: Uputstvo za uzorkovanje zemljišta pod vinogradima Prilog: Pedološka karta sa granicama Mlavskog vinogradarskog rejona i vinogorja

Zemljište je kompleksan i dinamičan ekosistem u kome se većina bioloških procesa odvija zahvaljujući mikroorganizmima. Osnovni biogeni elementi u zemljištu se nalaze pretežno vezani u organskim i neorganskim jedinjenjima i u tom obliku nisu direktno dostupni biljkama. Mineralizacija organskih jedinjenja do neorganskih i mobilizacija teško rastvorljivih neorganskih jedinjenja, odvija se zahvaljujući delovanju mikrobioloških enzima, a hranljivi elementi prevode se u oblike koje biljke mogu da usvajaju. Na taj način, mikroorganizmi obezbeđuju biljke asimilativima, a direktno su uključeni i u formiranje prinosa gajenih biljaka. Plodnost zemljišta određena je njegovim sastavom i svojstvima. Osobine zemljišta najviše utiču na raznovrsnost, brojnost i enzimatsku aktivnost mikroorganizama, a za sve tipove zemljišta karakteriše smanjena brojnost i aktivnost mikroorganizama na većim dubinama.

Vinogradarstvo i vinarstvo u poljoprivredi Republike Srbije zauzima značajno mesto prema istorijatu, privrednom dohotku, potencijalu i tendenciji razvoja. Vinogradarstvo u Republici Srbiji je, posebno u proteklih 20 godina, doživelo veliku promenu. S jedne strane, desila se velika devastacija, usled vlasničke transformacije, odnosno privatizacije velikih vinogradarsko-vinarskih preduzeća. Istovremeno je stvoren nov kvalitativni razvojni proces širenja privatnih vinogradarsko-vinarskih privrednih društava po ugledu na proizvođače u EU. Ministarstvo poljoprivrede i zaštite životne sredine je u potpunosti usaglasilo zakonodavstvo iz oblasti vinarstva i vinogradarstva sa zakonodavstvom EU. Takođe, definisana je nova rejonizacija vinogradarskih geografskih proizvodnih područja Srbije. Glavni razlog izrade nove rejonizacije je bio usaglašavanje sa reformom EU koja se odnosi na vinski sektor i uvođenje tzv. „PDO/PGI“ sistema geografskog porekla vina.

Intenzivna vinogradarska proizvodnja mora biti zasnovana na savremenim naučno-stručnim principima. Analiza zemljišta predstavlja nezaobilaznu, polaznu osnovu svake intenzivne biljne proizvodnje i prvi korak u podizanju vinograda. Analizu je neophodno uraditi pre podizanja vinograda, jer se napravljene greške kasnije teško ispravljaju. Na osnovu rezultata analize zemljišta može se odrediti potreba za đubrenjem i popravkama zemljišta. Pri podizanju višegodišnjih zasada teži se da zemljište bude na optimalnom nivou plodnosti. Takođe, nakon zasnivanja zasada neophodne su redovne analize u toku eksploatacije vinograda, a uzorkovanje zemljišta se obavlja svake 3-4 godine. Pravilnom primenom preporuka đubrenja ostvaruju se visoki i stabilni prinosi dobrog kvaliteta, uz profitabilnu i ekološki prihvatljivu proizvodnju.

Monografija se bavi karakteristikama zemljišta pod vinogradima u Niškom vinogradarskom rejonu. Materijal je sačinjen na osnovu rezultata opsežnih terenskih i laboratorijskih istraživanja, koja su obuhvatila deset reprezentativnih lokacija. Istraživanja su realizovana u okviru projekta Ministarstva poljoprivrede i zaštite životne sredine, Uprave za poljoprivredno zemljište. Monografija sadrži sedam poglavlja: Uticaj zemljišta na kvalitet i karakteristike vina, Neke bitne karakteristike terroir-a Niškog vinogradarskog rejona, Klasifikacija zemljišta Niškog vinogradarskog rejona i vodno-fizička svojstva zemljišta, Osnovna hemijska svojstva zemljišta, Sadržaj opasnih i štetnih materija (teških metala), Mikrobiološka svojstva zemljišta i Stepen erozione ugroženosti zemljišta Niškog vinogradarskog rejona. U prilogu monografije data je detaljna pedološka karta Niškog vinogradarskog rejona, prema pojedinačnim vinogorjima, sa klasifikacijom zemljišta, koja je usaglašena po domaćoj i međunarodnoj (WRB) klasifikaciji. Rezultati istraživanja su prikazani kao realni geo-podaci korišćenjem alata geografskog informacionog sistema (GIS) sa iznetim zaključcima i smernicama. Data je globalna procena plodnosti i kvaliteta zemljišta Niškog vinogradarskog rejona kroz opšte karakteristike ovog rejona, detaljne procene vinogradarskih parcela u okviru šest pojedinačnih vinogorja, fizičke i vodnofizičke karakteristike zemljišta, agrohemijske karakteristike, utvrđivanje odsustva opasnih i štetnih materija i mikrobiološke karakteristike zemljišta. Poseban doprinos monografiji čine poglavlja o karakteristikama terroir-a Niškog vinogradarskog rejona, uključujući istorijat vinogradarstva i vinarstva ovog područja, kao i podaci o eroziji kao prva istraživanja u ovom rejonu. Takođe, uvodni deo čini građa o značaju poznavanja zemljišnih karakteristika u vinogradarstvu. Monografija je namenjena proizvođačima grožđa i vina, kao i stručnjacima iz oblasti vinogradarstva i vinarstva, sa ciljem da ukaže, Tis book analyses the characteristics of soil under vineyards in Niš wine-making region. Te material comprises the results of the extensive field and laboratory studies which included ten most representative locations. The research was carried out within a project financed by Agricultural Land Directorate of the Serbian Ministry of Agriculture and Environmental Protection. There are seven chapters in the book: Effects of soil on wine quality and characteristics, Some important characteristics of Niš wine-making region terroir, Classification of Niš wine-making region soil and water-physical characteristics of the soil, Basic chemical properties of the soil, Content of dangerous and harmful metals (heavy metals), Microbiological properties of soil, and Degree of soil erosion threat to Niš wine-making region. In the annex to the book, there is a detailed soil map of Niš wine-making region, with individual vineyard areas and with soil classification in compliance with national and international (WRB) classifications. Research results are shown as real geo-data by using geographic information system (GIS) with conclusions and guidelines. Global assessment of soil fertility and quality of Niš wine-making region is given through general characteristics of the region, detailed assessments of vineyards within six individual vineyard areas, physical and water-physical properties of the soil, agrochemical properties, determination of absence of dangerous and harmful matters and microbiological characteristics of the soil. Special addition to the book are the chapters on characteristics of terroir of Niš wine-making region, including the historical overview of viticulture and wine-making in this region, as well as the first report on soil erosion in this region. Also, the introductory chapter highlights the importance of knowing and understanding soil characteristics in viticulture. Tis book is intended for grape growers and wine producers, viticulture and enology experts, and

Zemljište sa svojom florom i faunom predstavlja jedan od najraznovrsnijih i najvažnijih ekosistema na planeti. Najveći deo biološkog diverziteta agroekosistema nalazi se u zemljištu, a funkcije koje obavljaju živi organizmi imaju značajne direktne i indirektne efekte na rast i kvalitet useva, ciklus hranljivih materija, kao i održivost i produktivnost zemljišta. Zemljišni organizmi takođe značajno doprinose otpornosti određenog agroekosistema na različite abiotičke faktore. Zemljište je izvor hranljivih materija i vode za biljnu proizvodnju, služi biljkama kao oslonac za učvršćivanje korenovog sistema, osigurava raznovrsno stanište za brojne organizme, te ima ključnu ulogu u produkciji biomase i očuvanju biodiverziteta. Kao organsko-mineralni materijal koji se nalazi neposredno na površini zemlje, zemljište je pod stalnim uticajem abiotičkih i biotičkih faktora kao što su klima, živi organizmi i reljef.

The aim of this study was to investigate osmotic stress tolerance ability of Bradyrhizobium japonicum strains. The research was performed with 30 Bradyrhizobium strains from the collection of Institute of Field and Vegetable Crops Novi Sad, Serbia. Bradyrhizobium strains were tested on osmotic stress tolerance induced by supplementing the liquid yeast extract mannitol (YEM) medium with four different concentrations of polyethylene glycol (PEG) 6000. Polyethylene glycol (PEG) is more widely used than other substances (sugars or salts), because of its ability to decrease external water potential by binding water moleculs in solute, without penetrating the cell wall. Strain precultures were grown in 100 ml liquid YEM medium, with 150 rpm at 28 ± 2°C for 72h. To test strain osmotic stress tolerance, 1 ml of preculture was transferred in 50 ml YEM medium supplemented with four different PEG concentrations 9%, 17%, 24%, 36% (w/v), and in YEM medium without the added PEG (control treatment). Test cultures were incubated for 72h (28 ± 2°C, 150 rpm). Serial dilutions were prepared from the test cultures and spread onto an agarized YEM medium. Growth pattern was recorded by plate counts over colony forming units (CFU ml-1) five days after incubation at 28 ± 2°C, and expressed as log10 CFU ml-1.

The aim of this study was to isolate and identify Bradyrhizobium japonicum strains on the basis of molecular characteristics. From root nodules of different soybean cultivars were obtained 56 isolates, characterized according to morphological, cultural, and biochemical properties. Among these isolates, 33 isolates showing resemblance with Bradyrhizobium sp. were further subjected to molecular identification. Following DNA extraction, a partial 16S rDNA gene sequence from the isolates was amplified by PCR using universal primers fD1 (27F) and rP3 (1492R). Purification and sequencing of the amplified fragments were done in the biotechnology company Macrogen, Seoul, South Korea. Sequences were analyzed using the program FinchTV and BLAST (Basic Local Alignment Search Tool) and compared to sequences in GenBank and the Bradyrhizobium ID-database for identification. Comparison of the sequences with the Bradyrhizobium ID- database showed that all tested isolates were identified as Bradyrhizobium japonicum. Each isolate was deposited in the NCBI GenBank database under a unique accession number. Identification of Bradyrhizobium species from root nodules of soybean is of great importance because the symbiosis between rhizobia and legumes are a cheaper and usually more effective agronomic practice for ensuring an adequate supply of nitrogen for legumes, while preserving and improving fertility and productivity of soils., Cilj ovog rada je izolacija i molekularna identifikacija sojeva Bradyrhizobium japonicum. Na osnovu morfološke i biohemijske karakterizacije, od 56 izolata iz korenskih kvržica različitih sorti soje, 33 izolata za koje je utvrđena sličnost s Bradyrhizobium sp. bili su predmet dalje identifikacije. Nakon ekstrakcije DNK, parcijalna 16S rDNA genska sekvenca iz izolata je umnožena PCR metodom upotrebom univerzalnih prajmera fD1 (27F) i rP3 (1492R). Prečišćavanje i sekvencioniranje umnoženih fragmenata urađeno je u kompaniji Macrogen Ltd. (Seul , Južna Koreja). Pomoću programa FinchTV i BLAST (Basic Local Alignment Search Tool) analize, izvršeno je višestruko poređenje dobijenih sekvenci s GenBank bazom podataka. Poređenjem dobijenih sekvenci s Bradyrhizobium ID-bazom podataka svi ispitivani izolati identifikovani su kao Bradyrhizobium japonicum. Sekvence su deponovane u svetsku NCBI bazu uz dobijanje pristupnog broja (NCBI Acc. number). Identifikacija vrsta Bradyrhizobium-a poreklom iz korenskih kvržica soje od velikog je značaja jer je simbioza između rizobiuma i leguminoza isplativiji i obično efikasniji način snabdevanja biljaka azotom, a važno je i zbog očuvanja i unapređenja plodnosti i produktivnosti zemljišta.

During the last decades, intensive application of synthetic fungicides in the agricultural crop protection practice caused growing concern for the existence of toxic chemical residues in food as well as in the whole environment. Instead of using synthetic fungicides, it is suggested that crop protection be carried out by using preparations based on compounds of natural origin (secondary metabolites of plants or microorganisms, including macrofungi from Basidiomycota) as biological control agents. The potential of macrofungal species as biocontrol agents was analyzed in this investigation of eight autochthonous species from different locations in Serbia. Both the terricolous species: Coprinus comatus, Coprinellus truncorum, Amanita strobiliformis, Hydnum repandum and the lignicolous species: Flammulina velutipes, Stereum subtomentosum, Trametes versicolor and Bjerkandera adusta were examined, with an aim to detect some novel sources of antifungal agents. This study surveyed antifungal activity of selected macrofungal extracts (MeOH, EtOH and CHCl3) against phytopathogenic Fusarium and Alternaria strains isolated from garlic, soybean and rice: F. proliferatum, F. verticillioides, F. proliferatum, F. graminearum and A. padwickii. Microdilution method in 96 well micro-plates was applied for the estimation of antifungal effects of macrofungi extracts in the range from 24.75 to 198.00 mg/ml and determination of minimal inhibitory (MIC) and minimal fungicidal concentration (MFC). EtOH extract of mychorhizal species H. repandum showed antifungal activity against all analyzed phytopathogenic strains, with the strongest effect on Fusarium strains (MIC 24.75 mg/ml; MFC 24.75 mg/ml). Among others, MeOH extracts of S. subtomentosum and C. micaceus showed similar effects while only B. adusta showed slight effect on Fusarium strains (MIC 24.75-99.00 mg/ml; MFC 24.75-99.00 mg/ml) and none effect on A. padwickii. The obtained results indicate the possibility of using examined extrac, Tokom poslednjih decenija intezivna primena sintetičkih fungicida u zaštiti poljoprivrednih useva izaziva sve veću zabrinutost ljudi zbog prisustva toksičnih hemijskih ostataka u prehrambenim proizvodima kao i celoj okolini. Umesto korišćenja sintetičkih fungicida, preporučuje se da se zaštita useva vrši korišćenjem preparata na bazi jedinjenja prirodnog porekla (sekundarni metaboliti biljaka ili mikroorganizama uključujući i makrogljive iz razdela Basidiomycota) kao agense biološke kontrole. U ovom radu istraživan je potencijal agenasa biološke kontrole za osam autohtonih vrsta makrogljiva s različitih lokaliteta u Srbiji. Obe, terikolne vrste: Coprinus comatus, Coprinellus truncorum, Amanita strobiliformis, Hydnum repandum i lignikolne vrste: Flammulina velutipes, Stereum subtomentosum, Trametes versicolor i Bjerkandera adusta su istražene s ciljem da se otkriju neki novi izvori antifungalnih agenasa. U okviru ovog rada istražena je antifungalna aktivnost odabranih ekstrakata makrogljiva (metanolni, etanolni i hloroformski) protiv fitopatogenih sojeva Fusarium i Alternaria izolovanih s belog luka, soje i pirinča: F. proliferatum, F. verticillioides, F. proliferatum, F. graminearum i A. padwickii. Za procenu antifungalnog efekta ekstrakata makrogljiva upotrebljena je mikrodiluciona metoda mikrotitar pločama s 96 velova u opsegu koncentracija od 24,75 do 198,00 mg/ml i determinaciju minimalne inhibitorne (MIC) i minimalne fungicidne koncentracije (MFC). Etanolni ekstrakt mikorizne vrste H. repandum pokazao je atifungalnu aktivnost prema svim analiziranim fitopatogenim sojevima, sa najjačim efektom prema sojevima Fusarium (MIC 24,75 mg/ml; MFC 24,75 mg/ml). Između ostalog, sličan efekat pokazali su i metanolni ekstrakti S. subtomentosum i C. micaceus, dok je samo B. adusta imala blagi efekat na sojeve Fusarium (MIC 24,75-99,00 mg/ml; MFC 24,75-99,00 mg/ml), ali ne i na A. padwickii. Dobijeni rezultati ukazuju na mogućnost korišćenja ispitanih ekstrakata kao veoma efi

Plant growth-promoting rhizobacteria (PGPR) enhance plant growth and yield by various mechanisms which involve fixation of atmospheric nitrogen, production of siderophores, solubilization of minerals such as phosphorus, synthesis of phytohormones, etc. The aim of this study was to determine the effect of symbiotic nitrogen fixing bacteria Bradyrhizobium japonicum, applied alone or in co-inoculation with two different PGPR strains - Bacillus subtilis and Bacillus megaterium, on soil biogeny parameters, growth and yield of soybean cultivar Galina. This study was conducted on two-year experiment which was set up in four replications at experimental field of the Institute of Field and Vegetable Crops from Novi Sad. Soil biogeny was determined using the total number of microorganisms, number of azotobacters and dehydrogenase activity. Growth parameters were determined based on the height and weight of the aboveground plant parts and roots, number and mass of nodules, pod number, seed number and seed mass per plant. All treatments showed a positive effect compared to the control in both years of research. Co-inoculation had a greater impact on soil biogeny, growth and yield of soybean plants, while the best effect on nodules and yield parameters was achieved in the variant of single inoculation. On average, a higher percentage of increase was in the total number of microorganisms (5 – 37%) than in azotobacter population size (11 - 14%). The yield increase over the control ranging from 3,2% in the variant with Bradyrhizobium japonicum, to 11,7% in the case of co-inoculation with both strains of Bacillus.

Cilj ovih istraživanja bio je da se ispita uticaj sojeva Azotobacter chroococcum, Bacillus subtilis i Pseudomonas fluorescens na brojnost mikroorganizama u rizosferi kukuruza, Ogled je postavljen na zemljištu tipa černozem na oglednom polju Rimski šančevi, Instituta za ratarstvo i povrtarstvo. Primenjeni sojevi, kao i njihove kombinacije, delovali su stimula tivno na brojnost mikroorganizama u rizosferi kukuruza. Primenom mikroorganizama u proizvodnji kukuruza smanjila bi se upotreba hemijskih sredstava, odnosno đubriva i pesticida, a time i zagađenje zemljišta., The aim of this study was to examine the effect of Azotobacter chroococcum, Bacillus subtilis and Pseudomonas fluorescens on the microbial abundance in maize rhizosphere. Field trial was established on chernozem soil at Rimski šančevi experiment field of Institute of Field and Vegetable Crops. Applied strains, as well as their combinations stimulated the microbial abundance in maize rhizosphere. Application of microorganisms in maize production could reduce the use of chemicals, including fertilizers and pesticides, and thus the soil pollution.

The objective of this study was to investigate the microbial abundance in maize rhizosphere depending on the applied bacterial inoculants and the leaf stage of maize as well as to examine the effect of plant growth promoting rhizobacteria (PGPR) on the early growth of maize plants. In this experiment three bacterial species: Azotobacter chroococcum, Bacillus subtilis and Pseudomonas fluorescens applied individually and in mixture were used as inoculants. One hybrid of maize included in the tests: NS 6010 developed at the Institute of Field and Vegetable Crops in Novi Sad. Experiments were established in laboratory and in greenhouse. The number of the investigated microbial groups depended on the applied bacterial inoculants and the leaf stage of maize plants. Bacterial strains used in this study had a statistically significant influence on the number of microorganisms in maize rhizosphere and a positive effect on the early growth of maize. Bacterial inoculants increased plant height and weight of young maize plants., Cilj ovih istraživanja bio je da se odredi brojnost mikroorganizama u rizosferi kukuruza u zavisnosti od primenjenih bakterijskih inokulanata i faze rasta kukuruza kao i da se ispita efekat rizobakterija - promotora biljnog rasta (PGPR) na početni rast kukuruza. Kao inokulanti korišćene su tri vrste bakterija: Azotobacter chroococcum, Bacillus subtilis i Pseudomonas fluorescens primenjene pojedinačno i u smeši. U istraživanjima je korišćen jedan hibrid kukuruza: NS 6010 stvoren u Institutu za ratarstvo i povrtarstvo u Novom Sadu. Ogledi su postavljeni u laboratoriji i u žičari. Broj ispitivanih grupa mikroorganizama zavisio je od primenjenih bakterijskih inokulanata i faze rasta kukuruza. Sojevi bakterija ispoljili su statistički značajan uticaj na brojnost mikroorganizama u rizosferi kukuruza i imali su pozitivan efekat na rast biljaka kukuruza. Inokulacijom je povećana visina i masa biljaka kukuruza.

The effect on sugar beet yield parameters and microbiological soil sta­tus was studied using two techniques of sugar beet inoculation with strains of Azotobacter chroococcum. Cultivar 'Drena' was used in the study, and field trial was set under the conditions of organic farming system in Bački Petrovac. A mixture of three strains of Azotobacter chroococcum was used as microbial fertilizer. Inoculation was performed by: (A) incorporation of strains into soil before sowing; and (B) repeated incorporation of strains into soil two weeks after sowing. PGP characterization of the strains confirmed the ability of producing indole-3-acetic acid (IAA) from 12.63 μg ml-1 to 14.95 μg ml-1, nitrogen fixation, and P-solubilization. Positive effects on the number of azotobacter and free nitrogen fixers in rhizosphere were obtained by inoculation, as well as positive effects on the tested sugar beet yield parameters. The largest increase in root yield, yield of crystal sugar, and yield of polarised sugar compared with the control was obtained by repeated soil inoculation, ranging from 22 to 23%., Ispitan je efekat dva načina inokulacije šećerne repe sa sojevima Azotobacter chroococcum na parametre prinosa šećerne repe i mikrobiološki status zemljišta. U ispitivanjima je korišćena sorta Drena, a eksperiment je postavljen u sistemu organske proizvodnje u Bačkom Petrovcu. Kao mikrobiološko đubrivo korišćena je smeša tri soja Azotobacter chroococcum. Inokulacija je izvršena na dva načina: (A) inkorporacija sojeva u zemljište pre setve, (B) ponovljena inkorporacija sojeva u zemljište dve nedelje nakon setve. PGP karakterizacijom korišćenih sojeva utvrđena je sposobnost produkcije indol-3-sirćetne kiseline (IAA) od 12.63 μg ml-1do 14.95 μg ml-1, azotofiksacije i fosfosolubilizacije. Inokulacijom je dobijen pozitivan efekat na broj azotobaktera i slobodnih azotofiksatora u rizosferi, kao i na ispitivane parametre prinosa šećerne repe. Najveće povećanje prinosa korena, prinosa kristalnog i polarizacionog šećera dobijeno je na varijanti ponovljene inokulacije zemljišta i kretalo se od 22 do 23% u odnosu na kontrolnu varijantu.

The aim of this study was to compare abundance of microorganisms in the rhizosphere of four different medicinal and aromatic plant species (basil, mint, dill and marigold) grown under both conventional and organic management. The trials were set up on chernozem soil at experimental field of Bački Petrovac, Institute of Field and Vegetable Crops, Novi Sad (northern Serbia). Rhizosphere soil samples were collected in two sampling terms during 2015 (June 2 and July 28, 2015) and analysed by the indirect dilution method followed by plating of soil suspension on selective nutritive media. The obtained results showed significant differences in microbial abundance between plant species, growing systems and sampling terms. The highest number of azotobacters and cellulolytic microorganisms were obtained in rhizosphere of marigold, while total microbial number and fungi were the most abundant in rhizosphere of basil. The most common population of ammonifiers, free N-fixing microorganisms and actinomycetes were recorded in rhizosphere of dill. Significantly higher number of microorganisms was found in organic growing system compared to conventional, while the number of most tested microbial groups was higher at the first sampling period.

The aim of the experiment was to investigate the effect of strains Bradyrhizobium japonicum and Bacillus sp. on length and dry weight of soybean plants. Moreover, the strains were tested for their ability to produce indole-3-acetic acid and perform phosphate solubilization. The trial was established under semi-controlled conditions. Inoculation of soybean with Bradyrhizobium japonicum and Bacillus sp. increased height and dry weight of the aboveground parts and root of soybean plants. Most variants in which a mixture of Bradyrhizobium japonicum and Bacillus sp. was applied, resulted in significant increase in plant length and higher dry weight of the aboveground parts, compared to variants in which these bacterial strains were applied as single-component inoculants. Results for length and dry weight of the aboveground parts were lowest in uninoculated plants.

The biofertilizers are found positive contribution to soil fertility, resulting in an increase in crop yield without causing any environmental, water or soil pollution hazards. Nitrogen fixing and phosphorus solubilizing bacteria play an important role in nitrogen mobilization and phosphorus solubilization for the benefit of plant growth. A field experiment to study yield response of maize to inoculation with rhizobacteria, was conducted during 2013 at experimental field of Institute of Field and Vegetable Crops in Novi Sad. The maize hybrids (NS 3014, NS 4015, NS 5043, NS 6010 and NS 6030) were used in the study. The field experiment was laid out in randomized complete block design with four treatments (control and 3 inoculations) and four replications. Inoculation was done with Pseudomonas PS2, Bacillus Q7 and their mixture with Azotobacter chroococcum (Q7 + PS2 + AC). Application method was incorporation immidiately before planting with liquid culture of strains (1 l + 300 l H2O ha-1). The results showed significant increase in maize yield with inoculation treatments. The best effect on maize yield was achieved with mixture of strains (19.7%). Significantly higher yield was obtained for hybrids NS6010 and NS 6030. The highest increase in yield of maize was achieved with hybrid NS 6030 (32.2%). Statistically significant differences in comparison to the control were obtained on treatments with Q7 and PS2 + Q7 + AC.

Plant growth promoting rhizobacteria (PGPR) represent a wide variety of bacteria inhabiting the root surface and root vicinity. They are directly or indirectly involved in promoting plant growth and development via production and secretion of various regulatory compounds in the rhizosphere. PGPR are generally beneficial to a wide range of crops including maize. The main objective of this study was to determine the effect of PGPR strains on the microbial abundance in maize rhizosphere. The trial was conducted at Rimski Šančevi experimental field of Institute of Field and Vegetable Crops in Novi Sad, Serbia. The trial included five maize hybrids (NS 3014, NS 4015, NS 5043, NS 6010 and NS 6030) developed at the Institute and three treatments with microorganisms. Non-inoculated treatment was control. Inoculation was performed with Bacillus Q7, Pseudomonas PS2 and their mixture with Azotobacter chroococcum (Q7 + PS2 + AC). Application method was incorporation immediately before planting with liquid culture of strains (density 109 CFU/ml). It was observed that the certain treatment with rhizobacteria increased the number of all three studied microbial groups in the rhizosphere of the same hybrid. The best effect on the number of microorganisms in the rhizosphere of NS 6010 was achieved with Q7 + PS2 + AC, in NS 5043 with Q7 and with PS2 in NS 4015. The results obtained in this study indicate the importance of PGPR in crop production, which requires a constant expansion of knowledge about the mutual interactions of plants and microorganisms., Rizobakterije koje poboljšavaju rast biljaka (PGPR) predstavljaju širok spektar bakterija koje naseljavaju prostor oko/na površini korena. Direktno ili indirektno su uključene u ubrzanje rasta i razvoja biljaka putem proizvodnje i lučenja različitih regulatornih materija u rizosferu. PGPR su generalno korisne kod širokog spektra useva uključujući kukuruz. Osnovni cilj ovog istraživanja bio je ispitivanje efekta PGPR sojeva na zastupljenost mikroorganizama u rizosferi. Ogled je postavljen na eksperimentalnoj parceli Rimski šančevi Instituta za ratarstvo i povrtarstvo u Novom Sadu i uključivao je pet hibrida kukuruza poreklom iz Instituta (NS 3014, NS 4015, NS 5043, NS 6010 i NS 6030); kontrolu (bez inokulacije) i tri tretmana bakterijama koje poboljšavaju rast biljaka. Inokulacija je izvršena sa Pseudomonas PS2, Bacillus Q7 i njihovom mešavinom sa Azotobacter chroococcum (Q7 + PS2 + AC). Sojevi su primenjeni inkorporacijom tečne kulture (gustine 109 CFU/ml) neposredno pre setve. Rezultati su pokazali da kod određenog hibrida određeni tretman rizobakterijama povoljno utiče na brojnost kod sve tri analizirane grupe mikroorganizama. Najpovoljniji efekat na broj mikroorganizama u rizosferi hibrida NS 6010 postignut je primenom tretmana Q7 + PS2 + AC, kod NS 5043 primenom Q7, a kod NS 4015 primenom PS2.

The objective of this study was to compare the effects of conventional and organic production system on microbial activity in the soil cultivated with bean and maize crops. The trial in Đurđevo was set up according to the conventional farming system, while organic farming system was used in Futog. Two maize hybrids and two bean cultivars were used in the trial. Soil samples were collected in two periods during 2014 (before sowing, at flowering stage of bean crops, and at 9-11 leaf stage of maize) at two depths, at both locations. The following microbiological parameters were tested: the total number of micro­organisms, number of ammonifiers, Azotobacter sp., free nitrogen fixing bacteria, fungi, actinomycetes, and activity of dehydrogenase enzyme. The results showed that the total number of microorganisms, number of free N-fixers and dehydrogenase activity were high­er within organic production, while Azotobacter sp. was more abundant in conventional production. Variations in the number of ammonifiers, fungi and actinomycetes in relation to the type of production were not obtained. Significant differences in microbial activity were also obtained between period and depths of sampling., Cilj ovih istraživanja bio je da se uporede efekti konvencionalnog i organskog sistema gajenja na mikrobiološku aktivnost u zemljištu koje je pod pasuljem i kukuruzom kao usevima. Ogled u Đurđevu postavljen je u sistemu konvencionalne poljoprivredne proizvodnje, a ogled u Futogu u sistemu organske proizvodnje. U ogledima su korišćena dva hibrida kukuruza i dve sorte pasulja Instituta za ratarstvo i povrtarstvo u Novom Sadu. Uzorci zemljišta za mikrobiološke analize uzeti su tokom 2014. godine (pre setve i u fazi cvetanja pasulja, kao i u fazi 9-11 listova kukuruza), sa dve dubine, na oba lokaliteta. Mikrobiološka aktivnost praćena je na osnovu zastupljenosti ukupnog broja mikroorganizama, amonifikatora, Azotobacter sp., slobodnih azotofiksatora, gljiva, aktinomiceta i aktivnosti enzima dehidrogenaze. Rezultati su pokazali da su ukupan broj mikroorganizama, broj slobodnih azotofiksatora i dehidrogenazna aktiv­nost bili veći u sistemu organske proizvodnje, dok su vrste iz roda Azotobacter sp. bile zastupljenije u sistemu konvencionalne proizvodnje. Nisu zabeležene razlike u brojnosti amonifikatora, gljiva i aktinomiceta u zavisnosti od sistema gajenja. Takođe, značajne razlike u mikrobiološkoj aktivnosti utvrđene su između perioda i dubine uzorkovanja.

Raznovrsnost zemljišnih mikroorganizama od ključnog je značaja za očuvanje zdravlja i kvaliteta zemljišta. Širok spektar mikroorganizama odgovoran je za važne funkcije kako u neobradivim tako i u obradivim poljoprivrednim zemljištima. Zajednice zemljišnih mikroorganizama neizostavni su i najvažniji katalizatori biohemijskih procesa u zemljištu. Mikroorganizmi su ključna karika u procesu formiranja strukture zemljišta, u procesima razlaganja organske materije, kruženju ugljenika, azota, fosfora, i u uklanjanju toksina iz zemljišta. Diverzitet mikroorganzama u zemljištu određen je brojnim interakcijama između mikroorganizama i zemljišta, mikroorganizama i biljaka i složenim mirobiološkim intarakcijama. Smanjena raznovrsnost, brojnost i aktivnost mikroorganizama indikacija je zagađenog ili degradiranog zemljišta i njegove niske plodnosti. Stoga je u cilju očuvanja i zaštite agroekoloških sistema i u sistemima održive poljoprivredne proizvodnje, pored agrohemijskih analiza, neophodno pratiti i dinamiku mikrobiološke aktivnosti u zemljištu.

In this study we assessed the number of microorganisms in rhizosphere of peppermint (Mentha × piperita L.) as one of the important aromatic species in Serbia. The trial was set up on chernozem soil at experimental field of Bački Petrovac, Institute of Field and Vegetable Crops, Novi Sad (northern Serbia) in 2012, 2013 and 2014. Rhizosphere soil samples were collected from both conventional and organic grown peppermint. In each year of investigation two samplings (June and July) were performed for microbiological analysis. Soil samples were analyzed by the standard methods in four replications and average number of microorganisms was calculated at 1.0 g absolutely dry soil. The results were analyzed in accordance with three-way model of analysis of variance. The obtained results showed that a significantly higher number of ammonifiers, azotobacters and free nitrogen-fixing bacteria was recorded in 2012 compared to 2013 and 2014. Also, a significantly higher number of azotobacters and free nitrogen-fixing bacteria was obtained in organic than in conventional growing. In addition, significant differences in number of fungi and actinomycetes were recorded between the sampling terms, i.e. significantly higher numbers of these groups of microorganisms were found in the second term.

Korisni mikroorganizmi ili mikroorganizmi promotori biljnog rasta (PGPM) ispoljavaju efekat na rast i razviće biljaka azotofiksacijom, mobilizacijom hraniva (N, P, Fe) u zemljištu i produkcijom fitohormona te na taj način stimulišu rast biljaka, povećavaju prinos i štite biljke od patogena. Cilj ovih istraživanja bio je da se izvrši karakterizacija bakterija izolovanih iz rizosfere kukuruza, inokulacija semena kukuruza odabranim izolatima, ispitivanje efektivnosti primene pojedinačnih i združenih kultura izolata na mikrobiološku aktivnost u rizosfernom zemljištu, kao i na početni rast i razvoj biljke, sadržaj pojedinih hranljivih elemenata u biljnom materijalu i prinos kukuruza. Korišćeno je 50 izolata iz rizosfernog zemljišta hibrida kukuruza NS 6010 gajenog na zemljištu tipa karbonatni černozem (13 izolata roda Azotobacter, 16 izolata roda Bacillus, 15 izolata roda Pseudomonas, 6 izolata roda Streptomyces). Karakterizacija izolata obuhvatila je određivanje morfoloških, fizioloških, biohemijskih i PGP osobina. Inokulacija semena kukuruza izvršena je s osam odabranih izolata primenjenih pojedinačno i u smeši i to s tri izolata azotobaktera (Azb5, Azb8, Azb13), s dva izolata bacilusa (Bac9, Bac15 ), s dva izolata pseudomonasa (Pse1, Pse5) i s jednim izolatom aktinomiceta (Act6). U ogledima su korišćeni hibridi kukuruza NS 6010 i NS 6030 selekcionisani u Odeljenju za kukuruz Instituta za ratarstvo i povrtarstvo, a efektivnost primene odabranih izolata na mikrobiološku aktivnost u rizosfernom zemljištu, kao i na biljku kukuruza, ispitana je u polukontrolisanim i poljskim uslovima. Brojnost mikroorganizama određena je metodom agarnih ploča, a dehidrogenazna aktivnost spektrofotometrijskom metodom. Uticaj izolata na klijanje semena ispitan je u laboratorijskim uslovima. Uticaj izolata na početni rast biljaka ispitan je u fazama 3. i 5-7. lista merenjem visine i suve mase nadzemnog dela biljke. Sadržaj azota, fosfora, bakra i cinka u biljnom materijalu (nadzemni deo/list), Beneficial or plant growth promoting microorganisms (PGPM) exert effect on plant growth and development through nitrogen fixation, mobilization of nutrients (N, P, Fe) in soil and production of phytohormones and thereby stimulate plant growth, increase yield and reduce pathogen infection. The aim of this study was to perform characterization of bacteria isolated from maize rhizosphere, inoculation of maize seeds with selected isolates, testing the effectiveness of single and co-inoculation on microbial activity in rhizosphere, as well as on initial growth and development of plants, content of some nutrients in plant material and yield of maize. 50 isolates from rhizosphere of maize hybrid NS 6010 grown on calcareous chernozem soil (13 isolates of the genus Azotobacter, 16 isolates of Bacillus, 15 isolates of Pseudomonas, 6 isolates of Streptomyces) were used. Characterization of isolates included determination of morphological, physiological, biochemical and PGP traits. Inoculation of maize seeds was carried out with eight selected strains applied individually and in mixture, and that with three isolates of Azotobacter (Azb5, Azb8, Azb13), two isolates of Bacillus (Bac9, Bac15), two isolates of Pseudomonas (Pse1, Pse5) and one isolate of Streptomyces (Act6). The experimental objects were maize hybrids NS 6010 and NS 6030 developed at Maize Department, Institute of Field and Vegetable Crops, and the effectiveness of selected isolates on microbial activity in rhizosphere, as well as on maize plant, was tested in semi-controlled and field conditions. The number of microorganisms was determined by agar plates method, and dehydrogenase activity by spectrophotometric method. Effect of isolates on maize seed germination was tested in the laboratory. The effect of isolates on initial plant growth was tested at 3 and 5-7 leaf stages by measuring height and dry weight of above ground plant parts. The contents of nitrogen, phosphorus, copper and zinc in plant material (above g

Fixation of atmospheric nitrogen plays a significant role from the point of agricultural production. Therefore, the aim of this research was to determine the effects of soybean inoculation with two different nitrogen-fixing bacteria on yield and nitrogen fixation parameters. A two-year trial was set up on experimental field of Institute of Field and Vegetable Crops from Novi Sad on chernozem soil using a randomized block design with four replicates. The soybean cultivar Galina and three variants of inoculation were tested: 1. Bradyrhizobium japonicum, 2. Bradyrhizobium japonicum + Azotobacter chroococcum + humic acid, and 3. Bradyrhizobium japonicum + Azotobacter chroococcum. The effect of inoculation on yield, pod number, seed number and seed mass per plant was determined. The effectiveness of nitrogen fixation was determined based on the number and mass of nodules and nitrogen content in aboveground plant parts, roots, nodules and seeds. The average number and mass of nodules, nitrogen content and yield of soybean obtained in response to inoculation were higher compared to the control in both years of research. Inoculation had a positive effect on nodule number (35% increase), nodule mass (40% increase) and nitrogen content (34% increase - roots, 62% - aboveground parts, 27% - nodules, 31% - seeds). Significantly higher yield increase (16%) was registered in the case of co-inoculation with Azotobacter chroococcum, while the best effect on nitrogen content, nodules and yield parameters was achieved in the variant with Bradyrhizobium japonicum.

For higher productivity heavy doses of fertilizers and other agrochemicals are applied. This has led to the emergence of a movement forward specified farming concept based on the traditional farming philosophy known as organic systems. These systems do not use synthetic chemicals and in the long run way be more sustainable than inorganic and conventional farming. The purpose of this study was to investigate microbial abundance in rhizosphere and yield of bean and soybean in conventional and organic system growing. The trial was set up on chernozem soil at the Bački Petrovac experiment field of the Institute of Field and Vegetable Crops. Soil samples of rhizosphere were collected under conventional management and organic management. Samples for microbiological analyses were taken at two dates (1st June and 18th July). Soil microbial abundance was significantly greater in organic farming growing compared with conventional. The total number of microorganisms, number of ammonifiers, azotobacter, actinomycetes and fungi was higher in rhizosphere in organic production of bean than in rhizosphere of bean in conventional production. Similar results were obtained in rhizosphere of soybean in organic production compared to the conventional. Beside the higher of examined groups of microorganisms in rhizosphere of soybean, the higher number of celulolytic actinomycetes was obtained, too. The number of nodules on root of soybean in organic production was three times higher than in conventional. Grain yield was higher in conventional production than in organic, while in organic production greater yield quality, protein and oil content, was obtained.

The ability of legume plants to fix atmospheric nitrogen in symbiotic association with nodule bacteria, have great environmental and agricultural significance. Bradyrhizobium japonicum is the most common soybean microsymbiont. In order to overcome the negative effects of drought, more tolerant crops genotypes are created and agricultural practices are improved. Selection of effective strains of rhizobia more tolerant to water deficit is certainly a measure that can increase nitrogen fixation and improve soybean production under drought conditions. This study was focused on the impact of drought on antioxidant characteristics of symbiotic communities of soybean and different Bradyrhizobium japonicum strains from the collection of Institute of Field and Vegetable Crops. Drought stress conditions increased the activity of the soluble and ionically cell wall-bound peroxidases in plant roots and nodules. The antioxidant activities in the roots and nodules as well as the content of soluble proteins were significantly increased under conditions of water deficit. Increased protein content in stress conditions can be explained by the synthesis of proteins involved in antioxidant response and accumulation of plant proteins involved in adaptation to drought, as confirmed by a significant correlation between protein content and the activities of peroxidase in roots and nodules. The applied strain significantly affected the activity of soluble and cell wall-bound peroxidase, antioxidant activity and the content of soluble proteins. The applied strain had a greater impact on the studied parameters in plants that were exposed to water deficit compared to plants that were provided optimum water. Significant correlations between antioxidant activity and the activity of soluble and bound peroxidases in nodules and roots indicated a linked antioxidant response of plant and bacteria under stress.

The osmotic stress tolerance of B. japonicum strains assessed according to their persistence in PEG solution. The lowest tolerance to osmotic stress was observed in strain 511 (43.3%), and the highest tolerance was observed for strain D216 (3.3% growth reduction in presence of PEG). PGP traits of B. japonicum strains were tested. None of five B. japonicum strains produced siderophore, strains 511 and 518 had the urease ability, and only B. japonicum 518 strain showed the ability to solubilize insoluble tricalcium phosphate. RAPD analysis, using AP10, BC318, AF14 and SPH1 primers, indicated genetic differences between Bradyrhizobium strains. The first group (strains 3, 6 and 518) showed more than 80% similarity. Strains 511 and D216 formed separate clusters. Difference between strains D216 and the other strains were more than 60%, with maximum value of 72% in comparison with strain 511. Plant-growth promoting (PGP) traits, osmotic stress tolerance and RAPD analysis highlighted strain D216 as useful for further investigation of B. japonicum impact on drought reduction in symbiosis with soybean., Tolerantnost sojeva B. japonicum prema osmotskom stresu ispitana je na osnovu preživljavanja sojeva u rastvoru PEG-a. Najmanju tolerantnost prema osmotskom stresu pokazao je soj 511 (43.3%), dok je najtolerantniji bio soj D216 (sa 3.3% smanjenja rasta u prisustvu PEG-a). Ispitane su PGP osobine sojeva B. japonicum. Nijedan od pet sojeva B. japonicum nije produkovao siderofore, ureaznu aktivnost pokazali su sojevi 511 i 518, a sposobnost solubilizacije neorganskog tri-kalcijum fosfata imao je samo soj B. japonicum 518. RAPD analiza, prajmerima AP10, BC318, AF14 i SPH1, ukazala je na genetske razlike između sojeva Bradyrhizobium. Prva grupa (sojevi 3, 6 i 518) pokazala je više od 80% sličnosti. Sojevi 511 i D216 formiraju zasebne klastere. Razlika između soja D216 i ostalih sojeva bila je veća od 60%, a maksimalna divergentnost od 72% zabeležena je u poređenju sa sojem 511. PGP osobine, tolerantnost prema osmotskom stresu i RAPD analiza izdvojili su soj D216 kao veoma značajan za dalja istraživanja B. japonicum u smanjenju negativnih posledica suše na simbioznu zajednicu sa sojom.