Volume 72, Issue 9

The sampling sites situated in southwest Slovakia are according to environmental monitoring of Slovakia a part of strongly disturbed environment by heavy metals, mainly by high nickel concentrations. The aim of the present study was to characterise a complete microbial assemblage from a dump containing heavy-metal-contaminated waste as well as from farmland situated nearby this dump by using shotgun sequencing of 16S rDNA amplicons. It was found that nickel influenced both species richness and diversity and that microbiota of both samples differed significantly (Bray-Curtis dissimilarity 0.73) at genus level mainly by abundances of sequences from particular genera and occurrences of the unique genera in individual bacterial communities. In spite of these differences between microbial assemblages, both samples shared many bacterial genera that might constitute the specific nickel-resistant bacterial niche, and it was possible to delineate the core microbiome of our two samples at species level. The core set of 30 species, represented by the phyla Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Cyanobacteria, suggest that these species might form a “core microbiome” of the specific nickel-resistant bacterial niche.

New techniques to estimate the extent and persistence of soil water repellency (SWR) were compared with commonly used techniques in assessing the results taken in the long-term agricultural experimental orchards in northern Israel irrigated with either freshwater (FW), primary treated wastewater (WW) or (secondary or tertiary) treated wastewater (TWW), where SWR induced by irrigation was registered (Ha Ma’apil, Neve Etan, and Shafdan). The extent of SWR was assessed by the repellency index RI, combined repellency index RI c and modified repellency index RI m . The persistence of SWR was assessed by the water drop penetration time WDPT and water repellency cessation time WRCT. Soils from different textural classes were classified as slightly to strongly water repellent according to WDPT or RI values. Relationship between RI c and RI values can be well fitted by the linear equation, i.e., RI c could be a good substitute for RI. Relationships between WRCT and WDPT values as well as RI m and RI c or RI values cannot be accurately described by the linear equation, i.e., RI m is not a good substitute for RI for the values taken in this study.

Quantifications of root system architecture and growth dynamics became essential in sustainable agriculture, bio-engineering and underground ecology in general. Assessing of root architectural parameters is still challenging also owing to different methodological challenges and high-cost facilities required. The objective of this study was to design and examine a performance of a simple experimgal set-up for monitoring and analyses of root system architecture. The proposed system was examined with two cover crops – white mustard and sweet clover – grown in sand filled pots under controlled climate conditions for several weeks. Root systems of each crop were harvested in regular intervals of 2 to 3 weeks in 3 to 4 replicates. After careful washing, the intact root systems were photo captured in water filled cylinder in their quasi-natural position over entire rotation and then scanned using a flatbed professional scanner. The gained images (photos and scans) were analysed with AutoCAD and WinRhizo software for measuring of diverse root architectural parameters for modelling. The results showed that the selected experimental and methodical approaches were appropriate for monitoring and delivering data of good quality. Both, digital camera and scanner were regarded as essential complementary imaging tools for correct assessment of the root system architecture. To maximise the accuracy of the measurements, recommendation for improving the system were provided. Extracted root data are intended for parametrisation of root architectural models, but they also support researcher and experts in their efforts to improve crop uptake efficiency in sustainable agriculture and for bio-engineering purposes.

The benefits of biochar application are well described in tropical soils, however there is a dearth of information on its effects in agricultural temperate soils. An interesting and little explored interaction may occur in an intensive agriculture setting; biochar addition may modify the effect of commonplace N-fertilization. We conducted a field experiment to study the effects of biochar application at the rate of 0, 10 and 20 t ha −1 (B0, B10 and B20) in combination with 0, 40 and 80 kg N ha −1 of N-fertilizer (N0, N40, N80). We followed nitrous oxide ( N 2 O ) emissions, analysed a series of soil physicochemical properties and measured barley yield in a Haplic Luvisol in Central Europe. Seasonal cumulative N 2 O emissions from B10N0 and B20N0 treatments decreased by 27 and 25% respectively, when compared to B0N0. Cumulative N 2 O emissions from N40 and N80 combined with B10 and B20 were also lower by 21, 19 and 25, 32%, respectively compared to controls B0N40 and B0N80. Average pH was significantly increased by biochar addition. Increased soil pH and reduces NO3− $\begin{array}{} \displaystyle NO^-_3 \end{array} $ content seen in biochar treatments could be the two possible mechanisms responsible for reduced N 2 O emissions. There was a statistically significant increase of soil water content in B20N0 treatment compared to B0N0 control, possibly as a result of larger surface area and the presence of microspores having altered pore size distribution and water-holding capacity of the soil. Application of biochar at the rate of 10 t ha −1 had a positive effect on spring barley grain yield.

Catchment scale hydrological models are promising tools for simulating the effect of catchment-specific processes and management on soil and water resources. Here, we present a model intercomparison study of runoff simulations using three different semi-distributed rainfall-runoff catchment models. The objective of this study was to demonstrate the applicability of the Hydrologiska Byrans Vattenavdelning (HBV-Light); Precipitation, Evapotranspiration and Runoff Simulator for Solute Transport (PERSiST); and INtegrated CAtchment (INCA) models on Somogybabod Catchment, near Lake Balaton, Hungary. The models were calibrated and validated against observed discharge data at the outlet of the catchment for the period of January 1, 2006 –July 12, 2015. Model performance was evaluated using graphical representations, e.g. daily and monthly hydrographs and Flow Duration Curves (FDC) and model evaluation statistic; Nash–Sutcliffe efficiency (NSE) and coefficient of determination ( R 2 ). The simulation results showed that the models provided good estimates of monthly average discharge (0.60–0.90 NSE; 0.60–0.91 R 2 ) and satisfactory results for daily discharge (0.46–0.62 NSE; 0.50–0.67 R 2 ). We found that the application of hydrological models serves as a powerful basis for ensemble modelling of average runoff and could enhance our understanding of the eco-hydrological and transport processes within catchments. On the other hand, it can highlight the uncertainty of model forecasts and the importance of goal specific evaluation.

Water shortage is a global challenge and affects crop growth and development seriously. Stoma is the main channel of plant water transpiration. Water transpiration through stomata is an endothermic process and affects temperature of plants, especially leaf surface. In this study, we established a method for screening maize seedling mutant with abnormal leaf temperature by far infrared imaging. We found that seedling mutants with abnormal leaf temperature manifested different drought tolerance. Mutants with lower leaf temperature demonstrated faster moisture loss rate, poorer drought tolerance, higher osmotic potential, lower leaf relative water content, more accumulation of hydrogen peroxide, more serious cell membrane damage and more robust root systems and biomass under drought treatment, which are opposite in maize seedling mutants with higher leaf surface temperature compared with the corresponding control. Taken together, the method we established is an effective way to screen maize mutants with abnormal drought response.

Raman spectroscopy was used to investigate the shifts of vibrational marker bands of genomic double-stranded DNA (dsDNA) extracted from Elodea canadensis (Michx. 1803) young and senescent leaves that were used as an experimental model. Spectra were obtained using Renishaw inVia Reflex system with NIR 785.0 nm diode laser excitation in the Raman shift range 620–1,720 cm –1 . Additionally, the dsDNA samples were analyzed by gel electrophoresis and spectrophotometry. The identified patterns showed that the Raman bands intensity depends on the plant dsDNA quality and condition. Spectra from smeared dsDNA differ from high-molecular dsDNA and thus can be easily identified. However, the full range spectrum intensity of smeared dsDNA was significantly decreased, but some of the high-intensity peaks from dsDNA extracted from young leaves disappeared or their intensities were significantly reduced relative to other samples. Due to the decrease of the total intensity of all peaks, an increase in the number of low-intensity peaks over the entire length of the spectrum was observed.

Improving oil yield of Indian mustard ( Brassica juncea ) is exigent as it is a major oilseed crop of Indian subcontinent, which has severe shortage of vegetable oil production in the world. Some of the regulators of seed development have been shown to improve oil yield in Arabidopsis . Arabidopsis KLUH ( AtKLUH ), a maternal regulator of seed size, has been shown to control seed oil content. In this study, we identified three homologs of AtKLUH in B . juncea , BjKLUH1 , BjKLUH2-1 and BjKLUH2-2 . We observed that BjKLUH1 differentially expresses in developing seeds in B . juncea accessions with varying seed size and oil content. Further, analyses for seed oil content in B . juncea transgenics carrying AtKLUH demonstrated an increase in seed oil up to 8.3% compared to wild-type plants. The results of this study suggest that KLUH may have a role in seed development and is a good candidate for engineering seed oil accumulation in B . juncea .

The ecological niches and species abundance distributions of chigger mites were studied on small mammal hosts captured from 34 sites in Yunnan Province of southwest China between 2001 and 2015. Levins’ niche breadth and Colwell-Futuyma’s method were used to quantitatively evaluate host-specificity and similarity of host selection. Hierarchical analysis was used to illustrate niche overlap among mite species. Most mite species had a wide range of hosts with low host specificity. The niche overlaps between different mite species did not correlate with their taxonomic positions. Some mite species from different genera showed high niche overlaps and some others within the same genus showed low niche overlaps. Preston’s lognormal distribution model was used to fit the theoretical curve of species abundance distribution of mite community on Rattus tanezumi , the most dominant host species. The total expected mite species were then estimated roughly based on Preston’s method. The theoretical curve tendency of species abundance distribution indicated that the majority of mite species were rare species and that there were few dominant species with abundant individuals. The total expected number of mite species on R . tanezumi was estimated to be 224 species, and 92 species were likely missed in the sampling investigation.

The oribatid mite genus Brassiella (Oribatida, Caloppiidae) is recorded for the first time from Taiwan. A new species of this genus is described from leaves of Tabebuia chrysantha of Qiaotou Sugar Factory; Brassiella taiwanica Ermilov sp. n. differs from all other species by the following combination of morphological traits: lamellae not reaching insertions of lamellar setae; lamellar setae dilated mediodistally, interlamellar setae leaf-shaped, bothridial setae globose; twelve pairs of notogastral setae developed, p 3 vestigial, p 1 and p 2 minute, other setae short, leaf-shaped; adanal lyrifissures located in horizontal position; leg solenidia φ on tibiae IV swollen distally. New generic diagnosis and an identification key to the known species of Brassiella are provided.

A study of differences in the water chemistry and macroinvertebrate composition after a decade was performed in a strongly acidified mountain stream in the Brdy Mountains. In 1999 and again in 2010 we carried out monthly sampling of stream water and macroinvertebrates. We detected significantly lower concentrations of SO42− $\begin{array}{} \displaystyle \rm SO_4^{2-} \end{array} $, Ca 2+ , Mg 2+ , Na + , NH4+$\begin{array}{} \displaystyle \rm NH_4^+ \end{array} $, Cl − and F − ions, reactive aluminium (R-Al) and its toxic form Al n+ , and significantly higher concentrations of total organic carbon (TOC) between 1999 and 2010, possibly indicating recovery of this stream from acidification, even though there was no significant difference in pH. The signs of a biological recovery from acidification included the first occurrences of less acid-tolerant macroinvertebrate taxa: the stonefly Diura bicaudata and the caddisfly Rhyacophila sp. We observed higher taxonomic richness in 2010 compared to 1999 and found several species typical of standing waters plus a few rare species. This could partly be attributed to the effects of logging in the catchment. If recovery from acidification continues, we expect a return of other less acid-tolerant taxa to this strongly acidified stream.

Carabid fauna is not sufficiently explored in Central and Western Balkan areas, especially in mountain ecosystems with unique biodiversity which is a result of specific environmental factors and geologic history. Furthermore, distribution of species and adaptation to varying environmental parameters change along the altitudinal gradients. All this highlights the need for biodiversity and ecological studies in order to assess the state of the mountain ecosystems and conservation significance. Carabids as good bioindicator group can be used as a tool for monitoring those changes. The aim of this study was to analyse the differences of body size distribution and mean individual biomass (MIB) of ground beetle assemblages as a response of changing conditions and vegetation types along an altitudinal gradient on Belasitsa Mountain in south Macedonia. Both parameters significantly decreased with increasing altitude and were consequently associated with the vegetation type. Larger bodied individuals and higher values of MIB were recorded in the white oak and oriental hornbeam forest stands with the values decreasing in sessile oak forests towards submontane and montane beech forest stands. This research yielded first list of carabid species inhabiting Belasitsa Mountain with insight of carabid body length and biomass distribution along altitudinal gradient.

Morphological description of the pistachio weevil, Polydrusus davatchii Hoffmann, 1956, is supplemented and an additional distinctive character of the subgenus Orodrusus to which this species belongs, the strongly reduced hair brushes on the tarsal segments, is reported. Polydrusus davatchii was known as a minor pest for pistachio trees in Iran until the first decade of the XXI century, but is considered now as an important herbivore in pistachio orchards in early spring. The adults were not found on other plants in the pistachio growing areas. Only females of this species are known. Polydrusus davatchii produces one generation a year and is distributed now almost throughout the pistachio cultivation areas in central and southern parts of Iran.

Until recently all the Alburnoides populations of the Macedonia-Thessaly and Western Aegean ecoregions were considered as Alburnoides bipunctatus thessalicus Stephanidis, 1950. Here a new species of spirlin, Alburnoides economoui , is described from the Spercheios River (Fthiotida Prefecture). It is distinguished from all other congeners in Greek river basins and the Danube and Elbe drainages by the combination of the following characters: a very sharp ventral keel, scaleless or with 1 – 2 scales; 12½–14½ branched anal-fin rays; 42–47 + 1–3 pored lateral line scales; 19–25 pre-dorsal scales; snout conical, slightly pointed; snout length shorter than eye diameter; pelvic-fin origin about midway between pectoral-fin and anal-fin origins or slightly closer to anal-fin origin. The name Alburnoides thessalicus is now restricted to the populations from the Pinios, Aliakmon and Axios/Vardar rivers. A redescription and designation of neotype for Alburnoides thessalicus is provided. The species can be distinguished from all other congeners in Greek river basins and the Danube and Elbe basins by the presence of a sharp ventral keel in only 2/3 of its length, variably scaled with modally 4–6 scales; usually 12½ branched anal-fin rays; 44–50 + 1−2 pored lateral line scales; 24–31 pre-dorsal scales; snout stout, slightly to clearly rounded; snout length about equivalent to the eye diameter; pelvic-fin origin closer to anal-fin origin than to pectoral-fin. Despite similar morphological characters when compared to other European Alburnoides species, A. economoui differs remarkably genetically from all other studied Alburnoides species. The interspecific genetic divergence based on cytochrome b nucleotide sequences ranges from 7.3 to 8.8% (uncorrected p-distance).

The antimicrobial peptide chensinin-1b is a potential therapeutic agent against bacterial infection, which was derived from chensinin-1, a naturally occurring antimicrobial peptide derived from Chinese brown frog Rana chensinensis . In a membrane environment, the NMR structure of chensinin-1b showed an α -helical segment between the residues Arg8 to Arg13. To characterize the relationship between the structure and activity of chensinin-1b, the α -helical segment was truncated from the whole sequence, and the new peptides P-1 and P-3 were obtained with sequences of HWRRFWHR and WRRFWHR, respectively. The peptides showed antimicrobial activities against both Gram-positive and Gram-negative bacteria. To improve the antimicrobial activities of P-1 and P-3, histidine residues in the sequence were replaced by arginines to increase their cationicity, which enhanced the antimicrobial activities of the new analogs P-2 (RWRRFWRR) and P-4 (WRRFWRR) by approximately 4-fold. The helicity of the peptides was completely disrupted, and the peptides did not show the regular secondary structural conformations in a membrane environment. Membrane depolarization studies demonstrated that the four peptides exerted their antimicrobial effects by damaging the cytoplasmic membrane. Of these peptides, P-4 exhibited the strongest depolarization ability, which indicated a strong ability to permeabilize the outer membrane and damage the integrity of the cytoplasmic membrane. Dynamic-light-scattering experiments demonstrated that P-1, P-3 and P-4 could dissociate lipopolysaccharide (LPS) micelles, which indicated that the peptides were able to traverse the LPS leaflet. These data suggest that the peptide P-4 could be a promising molecule for the development of peptide antibiotics with short sequences.

Migratory birds could be important vectors of pathogenic bacteria and antimicrobial resistance transmissions over long distances. The common crane ( Grus grus ) is one of the largest migratory birds in Europe which form numerous flocks during migration. The aim of the study was to analyse enteromicroflora of common crane and to analyse the occurrence of antibiotic resistant bacteria in faecal samples of common crane collected at the most important migration stopover site of this bird species in Slovakia, the Special Protection Area Senianske rybníky. Upon cultivation on selective media 182 bacterial isolates were identified by MALDI-TOF mass spectrometry and analysed for antibiotic resistance. The most prevalent species of enterococci in faeces of common crane was Enterococcus casseliflavus (80.2%). Among Enterobaceriaceae isolates the most frequently detected species was Escherichia coli (51.5%) followed by Pantoea agglomerans (20.8%) and Serratia liquefaciens (19.8%). Very low frequency of antibiotic resistant bacteria was detected in faeces of common crane during the three years research period. No antimicrobial resistance was detected in enterococci and a single ampicillin resistant Raoultella ornithinolytica isolate, carrying the bla KPC gene, was detected among enterobacteria. Our results suggest that contamination by common crane faeces represents minimal risk in terms of the spread of antimicrobial resistance in the environment. The presence of some pathogenic bacteria requires further investigation of the risk associated with the transmission of bacteria during migration of cranes.