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HOW DOES SECTORIAL PRUNING AFFECT THE VEGETATIVE GROWTH, PRODUCTIVITY AND FRUIT QUALITY OF SUBSTRATE-GROWN HIGHBUSH BLUEBERRY CV. 'BLUECROP'?
Get PDFThe impact of pruning techniques on the plant growth, yield components and fruit quality
traits of substrate-grown highbush blueberry (Vaccinium corymbosum) cultivar 'Bluecrop'
were evaluated over four years (2019-2022). The orchard was planted in the village of Gruža
(Knić municipality, Serbia) in the spring of 2017 with 5-year-old nursery plants using 113 l
polypropylene pots spaced 0.8 m apart in a row and 3.0 m between rows (4,170 plants/ha). At
the onset of the trial the ‘Bluecrop’ plants were 8 years old. The two pruning techniques were
applied: i) conventional pruning (CP) - removal of the most unproductive canes at the center
of the canopy, and weak and excessively fruiting shoots from the top of bushes, and ii)
sectorial pruning (SP) - only removal of basal canes in ¼ of the canopy each year. The
average number of basal canes per bush was significantly lower in SP than in the CP
treatment (14.4 vs. 17.4 canes bush-1
, respectively). SP plants had thinner canes than CP
plants, which increased over the years of the study and reached a maximum diameter of 11.12
mm in 2022. CP had a positive influence on fruit yield (5.98 kg bush-1
), which was associated
with a 20% higher number of fruits per bush than in sectorial pruned plants. The fruit yield
increased in the first three years of the study, reaching a maximum value in 2021 (7.57 kg per
bush), whereas an opposite trend was observed in average fruit weight over the years, with the
lowest value reached in the last harvest year (1.81 g). Fruit weight and soluble solids content
were not affected by the pruning method, while the content of total acids, total anthocyanins
and total phenolics were significantly higher in fruit harvested from the SP treatment (0.70%,
37.04 mg eq mvd-3-G /100 g FW and 1.18 mg eq GA/g FW, respectively) along with the total
antioxidant capacity (8.39 mg eq AsA /g FW)
Advantages and limitations of active phase silanization in PVDF composites: Focus on electrical properties and energy harvesting potential
Get PDFIn order to further improve the performance of 0.94[(Bi0.5Na0.5)TiO3]-0.06BaTiO3/
polyvinylidene fluoride (NBT-BT/PVDF) flexible composite films prepared by the
hot-pressing method, the effect of surface modification of the NBT-BT particles on
the structure and properties of the films was investigated. Two coupling agents,
namely, (3-aminopropyl)triethoxysilane (APTES) and dodecyl triethoxysilane
(DDTES) were added to enhance dispersion and interfacial adhesion of the active
phase powder with the polymer matrix. The highest amount of the electroactive
PVDF β-phase was formed in APTES-modified samples while in DDTES samples
mainly γ-phase was formed as shown by Fourier-transform infrared spectroscopy
analysis. Differential scanning calorimetry measurements indicated that the addition
of filler particles reduced the total crystallinity degree of the PVDF. Dielectric
permittivity values as well as dielectric losses decreased for silanized samples due
to reduced tension at the interface between particles and polymer. Strong intermolecular
interaction between the PVDF chains and the APTES-modified particles
led to enhanced breakdown strength of these samples. The highest level of
agglomeration in the DDTES-modified samples induced the deterioration of ferroelectric
properties. The highest voltage output of 15 V and 225 μW of powerwas
obtained for the APTES-modified harvester, evidencing their potential for energy
harvesting applications
Multidisciplinarity and humanities discourse: the study of light
Get PDFPojedini afirmisani dvadesetovekovni naučni stvaraoci koji su obrazovani u oblasti matematike, fizike ili tehničkih nauka, premostili su jaz između naizgled disparatnih oblasti nauke modulišući istraživanja ka aspektima svetlosti koji su instruktivni u humanistici. Pavle Florenski, Viktor Bičkov, Sergej Horuži, Maks Džemer i Dejvid Lindberg izučavali su svetlost u različitim kontekstima, od prirodnih i tehničkih nauka do istorije, filosofije, ikonografije, estetike i asketizma. Tokom perioda velikih ideoloških i društvenih promena u 20. veku, napori ovih naučnika da razotkriju istorijske i savremene aspekte fenomena svetlosti obogatili su različite oblasti u nauci, iako su se neki od njih susreli sa opstrukcijama i osudama. Pre više od dve decenije, inicijativa dr Dragiše Bojovića sa Univerziteta u Nišu otvorila je prostor u srpskoj nauci, ali i šire, za nove interdisciplinarne i multidisciplinarne integracije, uključujući i fotološke.Certain established twentieth-century scientists who were educated in the field of mathematics, physics or technical sciences, have bridged the gap between seemingly disparate fields of science by modulating their research towards aspects of light that are instructive in the humanities. Pavel Florensky, Viktor Bychkov, Sergey Horuzhy, David Lindberg and Max Jammer studied light in various contexts, from the natural and technical sciences to history, philosophy, Оrthodox iconography, aesthetics and asceticism. During the time of great ideological and social changes of the 20th century, their efforts to unravel the historical and contemporary aspects of the study of light phenomenon enriched various fields of science, although some of them met obstructions and condemnations. Two decades ago, the initiative of Dr. Dragiša Bojović from the University of Niš have opened space in Serbian science, but also more widely, for new interdisciplinary and multidisciplinary integrations, as well as for the photological studies
Anthelmintic Resistance in Gastrointestinal Nematodes of Sheep: Current Situation and Novel Strategies
Get PDFGastrointestinal nematodes nowadays represent a major obstacle to sustainable sheep farming due to their negative effect on animal health, welfare and productivity. Commercial drugs such as benzimidazoles, macrocyclic lactones and imidazothiazoles have been used with success in previous decades to control these parasites. However, their irrational application has led to the development of anthelmintic resistance and large economic losses, while the situation is expected to further deteriorate in the future due to the spread of resistance and the emergence of multi-resistant nematode strains. Thus, monitoring is of key importance, which involves the application of various in vitro and in vivo tests, as well as modern molecular methods in order to early detect the development of resistance and monitor the situation in a certain area. In addition, the problem of the exclusive application of chemical preparations is also reflected in the residues in meat and milk, as well as in the environment. This poses a risk to various organisms, including humans. For these reasons, it is necessary to define new strategies, which are based on the rational application of anthelmintics in terms of targeted treatments, targeted selective treatments, but also combination and rotation of preparations. The introduction of alternative methods into practice, such as phytotherapy, i.e. the use of plant preparations such as extracts and essential oils, direct and indirect biological control, development of vaccines, genetic selection of naturally resistant animals with appropriate management of pastures and nutritional status of animals are also needed, all with the aim of reducing application of commercial drugs. This implies an integrated approach to the control of gastrointestinal nematodes, which is the basis of future treatments
Phytohormone Profling of Malus domestica and Chenopodium murale Hairy Root Exudate: Association with Allelopathic Efects
Get PDFCompounds exuded from roots play a key role in regulating plant allelopathic interactions. However, phytochormone profling of root exudates and their contribution to an overall allelochemical activity of specifc plant species is neglected topic in
allelochemical research. Hairy root growth media of two diferent species, the fruit tree species Malus×domestica Borkh.
and the herbaceous weed species Chenopodium murale L. were collected and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). We found that most of the phytohormones exuded by
the hairy roots of C. murale and M. domestica were associated with the acidic fraction (96.8% and 98.9%, respectively),
including 2-oxindole-3-acetic acid, phenylacetic acid, salicylic acid (SA), benzoic acid (BzA), and abscisic acid, with SA
and BzA being the most abundant, while those associated with the basic fraction, including cytokinins and the ethylene
precursor 1-aminocyclopropane-1-carboxylic acid, accounted for only 1% of the plant growth substances detected in both
species. Exogenous application of 0.2 µM SA, which was released from the hairy roots of C. murale and accumulated in
the culture media for four weeks, signifcantly impaired hairy root growth of M. domestica and also shoot and root growth
of Arabidopsis seedlings. The disruptive efect of 0.2 µM SA on the membrane potential of M. domestica hairy root and
Arabidopsis root cells was determined. The data obtained could be useful for planning further studies aimed at clarifying
the contribution and role of exuded phytohormones to the overall allelopathic potential of these two plant speciesThis version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s00344-024-11328-
Length-weight relationship and condition factor of the common roach (Rutilus rutilus) from Perućac reservoir
Get PDFLength-weight relationship (LWR) and condition factor (CF) of 52 roach individuals from Perućac reservoir, Serbia were analyzed. Total length was 22.5±2.6 cm and weight 140.3±49 g. Upon calculating LWR, final values of a=0.0223, b=2.7972, and r2=0.9272, have implicated negative allometric growth. CF value was 1.19±0.12 which indicated a good fish condition and it decreased with growing length of the body. We had also compared our results with LWR results of common roach in other regions to get an insight into the health condition of common roach in Perućac reservoir. Results showed that the individuals of common roach from Perućac reservoir differed from the other populations, mostly by growth – b parameter that was significantly lower than most of other localities. Results of this study provides new insights in LWR of common roach, health condition and can affect the decision making of fisheries management in the researched reservoir
Waterlogging-induced antioxidative response of Solanum nigrum
No full textThe objective of this study was to investigate the effect of waterlogging, followed by a recovery period, on the antioxidative metabolism in Solanum nigrum leaves. S. nigrum, commonly known as nightshade is broadly used in traditional medicine, and also generally known as a hyperaccumulator of heavy metals. In this experiment, in the phase of six fully developed leaves, the plants were subjected to 9-day waterlogging, followed by 9-day recovery treatment. The flooding led to an accumulation of leaf epidermal flavonoids for 25% and this tendency continued during the recovery period (also for 25%). While waterlogging and recovery had no effect on photosynthetic efficiency of PS II, chlorophyll content decreased by 15-25% during the recovery. Additionally, the fresh-to-dry ratio of combined leaves and stem under stress was reduced by more than 25% compared to the control, indicating growth inhibition and/or cell wall rigidity. Due to reduced oxygen availability, catalase (CAT) activity was twofold lower in waterlogged conditions compared to the control, and the same results were obtained in the recovery phase. Remarkable increase in POD (more than 50%) accompanied by twofold decrease in CAT implied redistribution of metabolites related to H2O2 under those conditions, which require further extensive investigation. Although the activity of ascorbate peroxidase was not affected by waterlogging, content of reduced ascorbate and reduced glutathione were slightly elevated under stress conditions, implying that activation of antioxidative metabolism supports plant adaptation to low oxygen conditions
Exploring the Antibacterial Potential of Lamiaceae Plant Extracts: Inhibition of Bacterial Growth, Adhesion, Invasion, and Biofilm Formation and Degradation in Pseudomonas aeruginosa PAO1
No full textIn response to the global rise in antibiotic resistance and the prevalence of bacterial biofilm-related infections, the antibacterial efficacy of methanolic, ethanolic, and aqueous extracts of 18 Lamiaceae plants from Serbia was evaluated. The total coumarins and triterpenes were detected spectrophotometrically, while a microdilution assay measured their effects on bacterial growth. Additionally, the impact of these extracts was assessed on Pseudomonas aeruginosa PAO1 adhesion and invasion in human fibroblasts and biofilm formation and degradation. The alcoholic extracts had the highest phytochemical content, with Teucrium montanum and Lavandula angustifolia being the richest in coumarins and triterpenes, respectively. Gram-positive bacteria, particularly Bacillus subtilis, were more susceptible to the extracts. Hyssopus officinalis ethanolic and Sideritis scardica methanolic extracts inhibited bacterial growth the most efficiently. Although the extracts did not inhibit bacterial adhesion, most ethanolic extracts significantly reduced bacterial invasion. Origanum vulgare and H. officinalis ethanolic extracts significantly inhibited biofilm formation, while Teucrium chamaedrys extract was the most active in biofilm degradation. This study significantly contributes to the literature by examining the antibacterial activity of Lamiaceae extracts, addressing major literature gaps, and underscoring their antibacterial potential, particularly Satureja montana and O. vulgare ethanolic extracts, linking their efficacy to coumarins and triterpenes
Effects of Trace Elements on the Fatty Acid Composition in Danubian Fish Species
No full textIn this study, the concentrations of metals and trace elements (As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn) were determined in the muscle tissue of adult roach and white bream at two different sites in the Belgrade section of the Danube. Twenty-six fatty acids, consisting of nine saturated FA (SFAs), seven monosaturated FA (MUFAs) and ten polysaturated FA (PUFAs), were identified. The analysis of the concentration of metals and trace elements of the roach and white bream showed species-specific differences in their bioaccumulation. Four of all elements analyzed (As, Hg, Ni and Pb) correlated significantly with the changes in FA profiles in fish from both sampling sites, with the exception of Cu, which correlated with the FA profile at the site before, and Zn, whose concentration influenced the FA profile at the site after wastewater discharges. The lower PUFA content in the fish from a site under higher environment pressure could indicate that the fish are stressed. The results suggest that changes in lipid composition may be one of the protective mechanisms of cells to cope with anthropogenic stressors
CHLORELLA SOROKINIANA – A POTENTIAL BIOFACTORY OF METAL CLUSTERS
No full textMicroalgae are known to accumulate metals either to opportunistically use the abundance of
essential elements for their metabolic needs or to adapt to metal excess that comes from natural
deposits or anthropogenic sources, such as mining and industrial drainage. Genus Chlorella is of
significant environmental and biotechnological importance in relation to the tolerance to intense
metal polution (1). To study the faith of manganese and copper, both esential elements but also
polutants, after interaction with the algal cells, C. sorokiniana was exposed to their increased but
non-lethal concentrations (1 mM both). According to XAFS (X-ray absorption fine structure
spectroscopies), after the initial biosorption and transport, both metals accumulate in the form of
clusters. Manganese takes the form of multi-valent Mn-O-Ca clusters, with structure and redox
properties matching those of the tetramanganese-calcium cluster in oxygen evolving complex (OEC)
in PSII (Vojvodi’ et al., 2022). The cluster contains Mn3+ and Mn4+ oxidation states as in OEC, with
reduction and oxidation peak current potentials that correspond to potentials of OEC cluster states
in Kok cycle. The Mn-O-Ca cluster was the dominant Mn-containing species in C. sorokiniana.
These findings may have important implications for the developement of artificial water-splitting
catalysis. As for copper, it was found in unchanged Cu2+ oxidation state bound to phosphate ions
Cu3(PO4)2, and reduced to Cu1+ forming structural sequences such as Cu(I)-Cu(I), Cu(I)-O-Cu(II),
and Cu(II)-O-Cu(II) (Vojvodic et al. 2020). These sequences strongly resemble structural and redox
intermediates of dicopper and tricopper bioclusters in monooxygenases and oxidases that oxydize
the C-H bond in alkanes and phenolates, or catalyze the oxydation of various substrates by O2. The
development of synthetic metal cluster compounds that model/mimic bioclusters has an immense
importance for industrial catalysis, advanced photochemical and redox processes. Chemical
synthesis of metal clusters comes with undesired chemical waste and long process times, and the
ideal way to make cluster chemistry greener may be to utilize living organisms such as C.
sorokiniana for the sustainable production of clusters