Shoot Samples Research Articles

Predicting terpene content in dried conifer shoots using near infrared spectroscopy

Terpenes are phytochemicals found in multiple plant genera, especially aromatic herbs and conifers. Terpene content quantification is costly and complex, requiring the extraction of oil content and gas chromatography analyses. Near infrared (NIR) spectroscopy could provide an alternative quantitative method, especially if calibration can be developed with the spectra of dried plant material, which are easier and faster to acquire than oil-based spectra. Here, multispecies NIR spectroscopy calibrations were developed for total terpene content (mono- and sesquiterpenes) and for specific terpenes (α-pinene, β-pinene and myrcene) with five conifers species ( Picea glauca, Picea rubens, Pinus resinosa, Pinus strobus and Thuja occidentalis). The terpene content of fresh shoot samples was quantified with gas chromatography. The NIR spectra were measured on freeze-dried samples (n = 137). Using a subset of the samples, modified partial least squares regressions of total terpene and the three individual terpenes content were generated as a functions of the NIR spectra. The standard errors of the internal cross-validations (values between 0.25 and 2.28) and the ratio of prediction to deviation ratios (RPD values between 2.20 and 2.38) indicate that all calibrations have similar accuracy. The independent validations, however, suggest that the calibrations for total terpene and α-pinene content are more accurate (respective coefficient of determination: r2 = 0.85 and 0.82). In contrast, calibrations for β-pinene and myrcene had a low accuracy (respectively: r2 = 0.62 and 0.08), potentially because of the low concentration of these terpenes in the species studied. The calibration model fits (i.e., r2) are comparable to previously published calibration using the spectra of dried shoot samples and demonstrate the potential of this method for terpenes in conifer samples. The calibration method used could be useful in several other domains (e.g. seedling breeding program, industrial), because of the wide distribution of terpenes and especially of pinenes.

Comparative effects of cantharidin and endothall on gene expression and activity of antioxidant enzymes in Cichorium intybus L.

Cantharidin and its analog, endothall, are known to have phytotoxic effects and their mechanism of action involves the inhibition of phosphatases. Enzymes and antioxidant compounds act as barriers against phytotoxic compounds. Catalase and peroxidase are among the most important antioxidant enzymes. Cichorium intybus L. has traditionally been used for its medicinal properties and contains various phytochemical and enzymatic compounds. The present study aimed to investigate the comparative effects of cantharidin and endothall with concentration of 2.5, 5.5 and 10 µg ml-1 on the changes in the gene expression of catalase and glutathione peroxidase. Furthermore, we assess the activities of these enzymes in the shoots and roots of Cichorium intybus L.. According to the findings, the expression of catalase and glutathione peroxidase increased in the samples treated with cantharidin more than endothall compared to the controls in both shoot (the most significant is in cantharidin with 2.5 µg ml-1 concentration) and root samples (the most significant is in cantharidin with 5.5 µg ml-1 concentration). In addition, the activity of catalase and concentrations of cantharidin (2.5 µg ml-1) in shoot samples led to the more intense stimulation of catalase and glutathione peroxidase compared to root samples. We suggest that cantharidin and endothall have negative effect on expression and absorption of antioxidant enzymes.

An electronic nose system for the monitoring of water cane shoots quality with swarm clustering algorithm

AbstractA fast, portable, nondestructive, and simple‐to‐operate method for determination of water cane shoot quality via an electronic nose (E‐nose) system is presented. The responses of E‐nose sensors to cane shoot samples during storage time are measured. Considering that one of the most common problems with fresh aquatic vegetables is the nearly negligible change in volatile organic compounds, a novel swarm clustering based on particle swarm optimization (SWC) algorithm is proposed to extract the effective features of the sensors responses. In SWC, the number of clusters is automatically estimated based on the neighborhood radius of the particles, which reduces the difficulty in determining the number of cluster. Traditional clustering algorithms, such as K‐means clustering (KMC) and hierarchical clustering analysis (HCA), are used for the purposes of comparison, and the changes in quality of cane shoot samples are quantitatively determined according to the hardness and pH. The results suggest that the E‐nose‐based SWC methodology is capable of accurately classifying the cane shoots freshness during the 20‐day storage time, which is much better than that of the comparative KMC and HCA methods. Additionally，quantitative analysis of the sensory evaluation, hardness, and pH is shown to have good agreement with the E‐nose system analysis results. Validation experiments show that unknown samples are successfully grouped into several different categories with a high correlation (R2 = .982) between unknown and known samples, demonstrating the potential use of E‐nose system to predict the freshness of the cane shoots.

A Fresh Look at Grape Powdery Mildew (Erysiphe necator) A and B Genotypes Revealed Frequent Mixed Infections and Only B Genotypes in Flag Shoot Samples.

Erysiphe necator populations, causing powdery mildew of grapes, have a complex genetic structure. Two genotypes, A and B, were identified in most vineyards across the world on the basis of fixed single nucleotide polymorphisms (SNPs) in several DNA regions. It was hypothesized that A populations overwinter as mycelia in grapevine buds, giving rise to so-called flag shoots in spring, and are more sensitive to fungicides than B populations, which overwinter as ascospores and become widespread later in the season. Other studies concluded that the biological significance of these genotypes is unclear. In the spring of 2015, there was a unique opportunity to collect E. necator samples from flag shoots in Hungary. The same grapevines were sampled in summer and autumn as well. A total of 182 samples were genotyped on the basis of β-tubulin (TUB2), nuclear ribosomal DNA (nrDNA) intergenic spacer (IGS), and internal transcribed spacer (ITS) sequences. Genotypes of 56 samples collected in 2009–2011 were used for comparison. Genotype A was not detected at all in spring, and was present in only 19 samples in total, mixed with genotype B, and sometimes with another frequently found genotype, designated as B2. These results did not support the hypothesis about temporal isolation of the two genotypes and indicated that these are randomly distributed in vineyards.

First report of apple rubbery wood virus 2 infection of apples in China.

Apple (Malus) is one of the most widely grown fruit trees worldwide, and viral diseases can severely inhibit its growth and development. Apple rubbery wood virus 2 (ARWV-2, family Phenuiviridae) is a negative-sense single-stranded RNA virus whose genome comprises three RNA segments (large: L, medium: M, and small: S) (Rott et al. 2018). This virus is associated with apple rubbery wood disease (Rott et al. 2018) and has previously been found in pear (Pyrus spp.) in China (Wang et al. 2019). In autumn 2019, six trees (one each of cvs. Honglu, Hongzhengzhu, Jinxiuhaitang, Liquanduanfu, Huahong-1, and Huahong-2) showing mosaic disease-like symptoms in the leaves and two trees (one each of cvs. Qingming-1 and Qingming-2) showing rusty skin symptoms (i.e., a large number of irregular rust spots on the peel's surface) in the fruits were found in Xingcheng, Liaoning province, China. Shoots of the diseased plants were collected, and total RNA was extracted from the phloem of the samples as described by Hu et al. (2015). Reverse transcription (RT)-PCR was used to detect various viruses including apple chlorotic leaf spot virus (ACLSV), apple stem pitting virus (ASPV), apple stem grooving virus (ASGV), apple necrotic mosaic virus (ApNMV), and ARWV-2 as well as apple scar skin viroid (ASSVd) using their respective primers (Supplementary Table 1). ACLSV, ASPV and ASGV were detected in all samples. ApNMV was detected in the six trees with leaf mosaic symptoms and ASSVd was detected in the two trees with apple rusty skin symptoms. Moreover, five trees (cvs. Honglu, Hongzhengzhu, Jinxiuhaitang, Qingming-1, and Qingming-2) tested positive for ARWV-2 in the RT-PCR assay. The PCR products of ARWV-2 from Honglu and Qingming-2 were cloned into the pMD18-T vector (Takara, Dalian, China), and one clone of each of the samples was sequenced. BLASTn analyses showed that they shared 98.2%-99.2% nt identity with ARWV-2 sequences (MT901298-MT901299) deposited in the GenBank database. A small RNAs (sRNAs) library was prepared for high-throughput sequencing (HTS) with the Solexa-Illumina platform using phloem tissue collected from a Qingming-2 tree in which apples with rusty skin symptoms were observed. A total of 3,7746,671 reads were obtained from the library. De novo assembly of the reads yielded 1,378 viral sequence contigs. Of those, 20 contigs with lengths ranging from 82 to 387 nt were mapped to the reference genome of ARWV-2 (accession nos. MT733339-MT733344, MT901300-MT901313). In addition, contigs of ACLSV, ASPV, ASGV, ApNMV and ASSVd were detected. To further confirm the HTS results, partial length fragments of segments L (717 bp), M (645 bp), and S (657 bp) of the ARWV-2 genome were amplified from Qingming-2 using primers (Supplementary Table 1) and sequenced. The resulting sequences, which have been deposited in GenBank under the accession numbers MT364372-MT364374, showed 97.2%, 97.8%, and 98.0% nt identity, respectively, with the corresponding segments of ARWV-2 isolate R7 (accession nos. MF062144-MF062146). To understand the infection status of apple trees in China with regard to ARWV-2, 116 apple shoot samples were randomly collected from commercial orchards in Liaoning, Shanxi, and Shandong provinces and subjected to RT-PCR to detect ARWV-2, ACLSV, ASGV, ASPV, ASSVd and ApNMV. In total, 49 (42.2%) of the 116 samples tested positive for ARWV-2, suggesting that this virus is wide spread in apple trees in China (Supplementary Table 2). The mixed-infection rates of ARWV-2/ApNMV and ARWV-2/ASSVd were 18.1% (21/116) and 3.4% (4/116), respectively. Among the 46 ARWV-2-positive samples, seven had mosaic disease-like symptoms in the leaves and three had rusty skin symptoms in the fruits. To our knowledge, this is the first report of ARWV-2 infection in apples showing rusty skin symptoms, as well as the first report of ARWV-2 infection in domestic apples in China. Further research is needed to understand the distribution of ARWV-2 in apple orchards throughout China, to confirm the relationship of ARWV-2 with different symptoms and to evaluate how ARWV-2 affects the performance and quality of apple.

Propagating sample variance uncertainties in redshift calibration: simulations, theory, and application to the COSMOS2015 data

ABSTRACT Cosmological analyses of galaxy surveys rely on knowledge of the redshift distribution of their galaxy sample. This is usually derived from a spectroscopic and/or many-band photometric calibrator survey of a small patch of sky. The uncertainties in the redshift distribution of the calibrator sample include a contribution from shot noise, or Poisson sampling errors, but, given the small volume they probe, they are dominated by sample variance introduced by large-scale structures. Redshift uncertainties have been shown to constitute one of the leading contributions to systematic uncertainties in cosmological inferences from weak lensing and galaxy clustering, and hence they must be propagated through the analyses. In this work, we study the effects of sample variance on small-area redshift surveys, from theory to simulations to the COSMOS2015 data set. We present a three-step Dirichlet method of resampling a given survey-based redshift calibration distribution to enable the propagation of both shot noise and sample variance uncertainties. The method can accommodate different levels of prior confidence on different redshift sources. This method can be applied to any calibration sample with known redshifts and phenotypes (i.e. cells in a self-organizing map, or some other way of discretizing photometric space), and provides a simple way of propagating prior redshift uncertainties into cosmological analyses. As a worked example, we apply the full scheme to the COSMOS2015 data set, for which we also present a new, principled SOM algorithm designed to handle noisy photometric data. We make available a catalogue of the resulting resamplings of the COSMOS2015 galaxies.

Phytoremediation of arsenic-contaminated soils by arsenic hyperaccumulating plants in selected areas of Enugu State, Southeastern, Nigeria

ABSTRACT Under the current study phytoremediation of arsenic from a tropical wetlands and lakes in selected areas of Enugu State was performed. Thirteen soil, plant root and shoot samples used in this research were collected respectively from the Adani Wetlands (six samples), Opi-Agu Lakes (four samples) and control sites (three samples). The plant and soil samples were analyzed in the laboratory using Standard Methods. In the study, As contaminated soils, with maximum As value was observed in Ada Rice Farm 2 (468.0 mg kg−1) followed by Ohuno Wetland 2 (442.0 mg kg−1) and Ada Rice Farm 3 (304 mg kg−1). The highest BCF value (3.31) was recorded in Pteridium Aquilinum root and 1.76 in Ludwigia Erecta shoot, and lowest amount of 0.73 was in Cyperus Exaltatus root and 0.14 in Nymphaea Maculata shoot of As contaminated soils. The translocation factor of As from soil to shoot in the agricultural soils (Adani areas) were found to be in the order of Corrigiola Telephiifolia (1.54) > Ludwigia Erecta (0.57) > Acroccras Amplectens (0.54) > Cyperus Exaltatus (0.45) > Cyperus Imbricatus (0.29) > Nymphaea Maculata (0.14) while in the lake soils (Opi-Agu areas), the translocation factor of As from soil to roots were measured in the order of Sacciolepis Cymbiandra (1.20) > Pteridium Aquilinum (0.53) > Lasimorpha Senegalesis (0.43) > Afromomum Daniellii (0.36). Present research showed that indicated plant species can be used as As accumulator in As polluted soils.

A non-destructive method to assess the status of Posidonia oceanica meadows

This paper presents a new non-destructive sampling technique that consists of cutting all of the leaves of a Posidonia oceanica shoot (with scissors) just above the ligula of the external leaves. Developed in an undisturbed meadow in Corsica (France) at depths of 12–15 m, this sampling technique is called the Non-Destructive Shoot sampling Method (NDSM). The results of using this method indicate that most biometric parameters and relevant water quality indices can be measured and calculated from seagrasses sampled using the NDSM. It was determined that sampling shoots using the NDSM ensured a 100% survival rate. Notably, the NDSM allowed sampled shoots to grow back to lengths similar to those of an adjacent control meadow within three months. Biochemical analyses indicated that meadow portions and seagrass leaves regrown after NDSM sampling differed little in chemical composition (C, N and P and essential metal micronutrients Fe, Cu, Zn, Mn, Ni and Mo) to control seagrasses. Thus, the NDSM limits the negative effects of the sampling. Although not lethal to the plant, sampling seagrasses according to the NDSM requires exemption from the competent authority according to local, regional or national regulations for each protected species.

Characterization of Immature Bamboo (Phyllostachys nigra) Component Changes with Its Growth via Heteronuclear Single-Quantum Coherence Nuclear Magnetic Resonance Spectroscopy.

A 6.2 m high immature bamboo (Phyllostachys nigra) was divided into seven fractions. The bamboo cell walls and lignin samples from young to old were characterized by 1H-13C correlation heteronuclear single-quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy both qualitatively and semiquantitatively. Mature bamboo and bamboo shoot samples were used as comparison references. HSQC-NMR analysis proved that cellulose and arabinoxylan have already deposited in bamboo shoot, and cellulose amount increased during growth. Lignin side chain linkage formation started from β-ether (β-O-4), then phenylcoumaran (β-5), and finally resinol (β-β). Ferulic acid and p-coumaric acid (pCA) were formed at the earlier stages in the immature bamboo, and the pCA proportion decreased throughout the lignification process. We propose that the bamboo lignification process is distinct from both woody and other herbaceous plants, where syringyl units deposited at the early stage and polymerized with the β-O-4 linkage. Then guaiacyl units formed gradually, and finally, p-hydroxyphenyl units formed.

Elemental Analysis of Plants Cultivated in Saline Soil by Laser-Induced Breakdown Spectroscopy (LIBS)

The production of crops and vegetables is largely affected by soil salinity which is a rising problem all over the world. The irrigation water and fertilizers are playing a vital role in increasing soil salinity. The elemental composition of the Aerva javanica plants grown in the salty area has been studied using laser-induced breakdown spectroscopy (LIBS). The soil, root, and shoot samples were collected from the Khewra Salt ranges, which is the world’s second-largest salt mine, located in the Punjab Province of Pakistan. This work aims to detect the major saline metals present in the plants grown in the salt-affected soil for which the electric field has been applied as an additional excitation source to enhance the emission signals using LIBS. Calibration-free LIBS has been applied to extract the concentration of soluble metals such as sodium, magnesium, and calcium in the root and shoot samples. The plasma temperature was determined using the Boltzmann plot method while the electron density was estimated from the Stark broadened profile of the calcium line at 616.12 nm.

Transcriptome Reveals the Specificity of Phyllostachys edulis ‘Pachyloen’ Shoots at Different Developmental Stages

Phyllostachys edulis ‘Pachyloen’ can have a stalk wall thickness of up to 2.5 cm at a height of 1.3 m, which is 1.8 times that of normal Moso bamboo (Phyllostachys edulis); this serves as an excellent cultivar, comprising both wood and bamboo shoots. We collected bamboo shoot samples of Phyllostachys edulis ‘Pachyloen’ and Moso bamboo on a monthly basis from September to April and used transcriptome sequencing to explore the differences in their development. The results showed that there were 666–1839 Phyllostachys edulis ‘Pachyloen’-specific genes at different developmental stages enriched in 20 biological processes, 15 cellular components, 12 molecular functions, and 137 metabolic pathways, 52 of which were significant. Among these, 27 metabolic pathways such as tyrosine metabolism and their uniquely expressed genes were found to play important roles in the thickening of Phyllostachys edulis ‘Pachyloen’. This study provides insights into the mechanisms underlying the thickening of the culm wall of Phyllostachys edulis ‘Pachyloen’.

Arsenic Uptake by Two Tolerant Grass Species: Holcus lanatus and Agrostis capillaris Growing in Soils Contaminated by Historical Mining.

The study focused on two grass species Holcus lanatus and Agrostis capillaris abundant in the sites of former As mining and processing in the Sudetes. Arsenic uptake from soils was examined to assess a risk associated with its accumulation in grass shoots and to check its dependence on soil fertilization. The research involved a field study and greenhouse experiment. In the field study, soil and plant samples were collected from 33 sites with 72–98,400 mg/kg total soil As. Arsenic uptake by grasses differed widely. Both species indicated a strategy typical for eliminators, although As concentrations in more than 50% of the shoot samples exceeded 4 mg/kg, a maximum permissible value for fodder. In the greenhouse experiment, commercial cultivars of both species were grown in five soils containing 394–19,600 mg/kg, untreated and fertilized. All seedlings died in the soil with highest total As, and considerable phytotoxicity was observed in other soils, particularly in nonfertilized ones. Fertilization resulted in the improvement of plant growth and reduction of As uptake except for Agrostis capillaris fertilized with manure. Further research should focus on identifying tolerant genotypes growing in extremely enriched sites and analysis of factors that will efficiently reduce As phytoaccumulation.

Chemometric characterization of heavy metals in soils and shoots of the two pioneer species sampled near the polluted water bodies in the close vicinity of the copper mining and metallurgical complex in Bor (Serbia): Phytoextraction and biomonitoring contexts

In terms of investigating the authentic plant biomonitoring and phytoextraction potentials, the samples of soils and shoots of the sun spurge (SS) and common nettle (CN), were collected near several polluted water bodies in the close vicinity of the copper mining/metallurgical complex in Bor (Serbia) and characterized with regard to the content of heavy metal(oid)s: As, Cd, Pb, Cu, and Zn. The methods applied in this work such as inductively coupled plasma-mass spectrometry, one-way analysis of variance, Pearson’s correlation study, hierarchical cluster analysis, and the calculation of bioaccumulation rates (expressed through the so called mobility ratios, MRs), provided very informative data on the potentials of both investigated pioneer species. The most important findings were: 1) In most cases, SS was more effective in metal extraction/translocation/bioaccumulation than CN, and especially with regard to Cu; in this particular case, extremely high concentrations were recorded and also, some significant MRs were calculated, which may be a signal of its promising potential for Cu-phytoremediation, practically, Cu-phytoextraction; however, generally, the values of most calculated MRs were very low (<1, for both plants); 2) The shoots of both plants reflected soundly the current status of metal presence in the studied environment and they can be recommended for seasonal screenings of a general level of metal pollution in the areas of interest; however, specifically, they cannot reflect quite correctly the level of soil pollution; 3) Soil Cu, and As were detected in alarming concentrations.

Study of seasonal variation in total polyphenol content in fresh leaves of tea [Camellia sinensis (L.) Kuntze

Experiment was conducted in the year 2018 and 2019 with an aim to study the variation in total polyphenol content in fresh green leaves of Camellia sinensis (L.) Kuntze var. assamica grown in Kangra Valley of Himachal Pradesh. The samples were collected at an interval of 14 days during three plucking seasons viz. April-June(Summer flush),July-August (Monsoon flush) and September- October (Back end flush). Samples of fresh green shoots collected in the 1st week of June recorded significantly highest total polyphenols (240.154g/kg) but was at par with the total polyphenols obtained in the samples of fresh green shoots collected in the 3rd week of May (237.136g/kg) during 2018. The fresh green shoots collected in 1st week of September recorded significantly lower TP than the rest of the treatments except the TP obtained from the fresh green shoots collected in the 3rd week of September,1st week of October,3rd week of October and 3rd week of July.

Circulation of Shiga Toxin-Producing Escherichia coli Phylogenetic Group B1 Strains Between Calve Stable Manure and Pasture Land With Grazing Heifers.

Escherichia coli strains carrying Shiga toxins 1 and 2 (stx1 and stx2), intimin (eae), and hemolysin (ehxA) production genes were found in grass shoot, rhizosphere soil, and stable manure samples from a small-scale cattle farm located at the center of Netherlands, using cultivation-dependent and -independent microbiological detection techniques. Pasture land with grazing heifers in the first year of sampling in 2014 and without grazing cattle in 2015 was physically separated from the stable that housed rose calves during both years. Manure from the stable was applied to pasture via injection into soil once per year in early spring. Among a variety of 35 phylogenetic distinctly related E. coli strains, one large group consisting of 21 closely resembling E. coli O150:H2 (18), O98:H21 (2), and O84:H2 (1) strains, all belonging to phylogenetic group B1 and carrying all screened virulence traits, was found present on grass shoots (10), rhizosphere soil (3), and stable manure (8) in 2014, but not anymore in 2015 when grazing heifers were absent. Presence and absence of these strains, obtained via enrichments, were confirmed via molecular detection using PCR-NALFIA in all ecosystems in both years. We propose that this group of Shiga toxin-producing E. coli phylogenetic group B1 strains was originally introduced via stable manure injection into the pasture. Upon grazing, these potential pathogens proliferated in the intestinal track systems of the heifers resulting in defecation with higher loads of the STEC strain onto the grass cover. The STEC strain was further smeared over the field via the hooves of the heifers resulting in augmentation of the potential pathogen in the pasture in 2014, whereas in 2015, in the absence of heifers, no augmentation occurred and only a more diverse group of potentially mild virulent E. coli phylogenetic group A and B1 strains, indigenous to pasture plants, remained present. Via this model, it was postulated that human pathogens can circulate between plants and farm animals, using the plant as an alternative ecosystem. These data indicate that grazed pasture must be considered as a potential carrier of human pathogenic E. coli strains and possibly also of other pathogens.

Concentration difference of auxin involved in stem development in soybean

Auxin regulates cell division and elongation of the primordial cells through its concentration and then shaped the plant architecture. Cell division and elongation form the internode of soybean and result in different plant heights and lodging resistance. Yet the mechanisms behind are unclear in soybean. To elucidate the mechanism of the concentration difference of auxin related to stem development in soybean, samples of apical shoot, elongation zone, and mature zone from the developing stems of soybean seedlings, Charleston, were harvested and measured for auxin concentration distributions and metabolites to identify the common underlying mechanisms responsible for concentration difference of auxin. Distribution of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and methylindole-3-acetic acid (Me-IAA) were determined and auxin concentration distributions were found to have a complex regulation mechanism. The concentrations of IAA and Me-IAA in apical shoot were significantly different between elongation zone and mature zone resulting in an IAA gradient. Tryptophan dependent pathway from tryptamine directly to IAA or through indole-3-acetonitrile to IAA and from indole-3-propionic acid (IPA) to IAA were three primary IAA synthesis pathways. Moreover, some plant metabolites from flavonoid and phenylpropanoid synthesis pathways showed similar or reverse gradient and should involve in auxin homeostasis and concentration difference. All the data give the first insight in the concentration difference and homeostasis of auxin in soybean seedlings and facilitate a deeper understanding of the molecular mechanism of stem development and growth. The gathered information also helps to elucidate how plant height is formed in soybean and what strategy should be adopted to regulate the lodging resistance in soybean.

Dry matter and macronutrient extraction curves of potato varieties in the Alto Paranaíba region, Brazil

ABSTRACT Information on plant nutrient extraction is of utmost importance for the management of fertilization in crops. The objective of the study was to determine the accumulation of dry matter mass in the tubers and aerial parts of the plants and to generate absorption curves of macronutrients N, P, K, Ca and Mg for the potato varieties Ágata, Asterix, Atlantic and Taurus. The shoot and tuber samples were collected at 6, 13, 54, 66, 70, 82 and 97 days after planting. The highest accumulation of dry matter was observed in the Asterix and Atlantic varieties. The varieties Asterix and Atlantic showed higher N and K extraction and, consequently, higher productivity, while Taurus and Ágata presented lower yields and nutrient extraction. The period of greatest demand for macronutrients for the varieties studied is during the tuber filling phase (40 days after plantation). The variation between potato varieties in macronutrient extraction indicates a need for differential management fertilization of the plants.

Maize root and shoot litter quality controls short-term CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; and N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O emissions and bacterial community structure of arable soil

Abstract. Chemical composition of root and shoot litter controls decomposition and, subsequently, C availability for biological nitrogen transformation processes in soils. While aboveground plant residues have been proven to increase N2O emissions, studies on root litter effects are scarce. This study aimed (1) to evaluate how fresh maize root litter affects N2O emissions compared to fresh maize shoot litter, (2) to assess whether N2O emissions are related to the interaction of C and N mineralization from soil and litter, and (3) to analyze changes in soil microbial community structures related to litter input and N2O emissions. To obtain root and shoot litter, maize plants (Zea mays L.) were cultivated with two N fertilizer levels in a greenhouse and harvested. A two-factorial 22 d laboratory incubation experiment was set up with soil from both N levels (N1, N2) and three litter addition treatments (control, root, root + shoot). We measured CO2 and N2O fluxes, analyzed soil mineral N and water-extractable organic C (WEOC) concentrations, and determined quality parameters of maize litter. Bacterial community structures were analyzed using 16S rRNA gene sequencing. Maize litter quality controlled NO3- and WEOC availability and decomposition-related CO2 emissions. Emissions induced by maize root litter remained low, while high bioavailability of maize shoot litter strongly increased CO2 and N2O emissions when both root and shoot litter were added. We identified a strong positive correlation between cumulative CO2 and N2O emissions, supporting our hypothesis that litter quality affects denitrification by creating plant-litter-associated anaerobic microsites. The interdependency of C and N availability was validated by analyses of regression. Moreover, there was a strong positive interaction between soil NO3- and WEOC concentration resulting in much higher N2O emissions, when both NO3- and WEOC were available. A significant correlation was observed between total CO2 and N2O emissions, the soil bacterial community composition, and the litter level, showing a clear separation of root + shoot samples of all remaining samples. Bacterial diversity decreased with higher N level and higher input of easily available C. Altogether, changes in bacterial community structure reflected degradability of maize litter with easily degradable C from maize shoot litter favoring fast-growing C-cycling and N-reducing bacteria of the phyla Actinobacteria, Chloroflexi, Firmicutes, and Proteobacteria. In conclusion, litter quality is a major driver of N2O and CO2 emissions from crop residues, especially when soil mineral N is limited.

Transformation of metals migration and biogeochemical cycling under the influence of copper mining production (the Southern Urals)

This study aims to estimate the migration and accumulation of metals (Cu, Zn, Fe, Mn, Ni, Pb, Cd, Co, Cr, Zr, Ba, and Sc) in terrestrial and aquatic landscapes. The research is based on the results of a long-term study (1998–2018) in one of the copper mining centers in Russia in the vicinity of Sibay City in the Southern Urals. The metal contents in samples of water, bottom sediments, soils, plant shoots (total aboveground phytomass samples, agrobotanical group samples, and shoots of indicator terrestrial and aquatic species), and fish muscles are measured. It is found that within natural geochemical anomalies, the migration ability of chemical elements in the soil–plant system and general biogeochemical cycle is low because of the high soil buffer capacity (determined by the high humus content, high percentage of fine fractions in granulometric composition, and neutral pH) and the adaptation of local plants to ore mineralization. The ecosystems affected by low pollution maintain natural homeostasis, stabilize the flow of chemical elements, and preserve the natural features of geographic components. Metal pollution and the replacement of natural steppe vegetation with secondary herbaceous-ruderal communities in critical areas near copper–zinc mining objects can stimulate the mobilization and inclusion of chemical elements in biogeochemical cycling, as well as the disruption of bonds among landscape components. The water systems in catenae function as stabilizers through a system of geochemical barriers and low uptake of metals by hydrophytes, such as the common reed (Phragmites australis).

Flow rate influence of the peristaltic-based pumps on the QCM sensor

The liquid injection is one of the crucial roles in the used of QCM sensors in a liquid application. Liquid sample injection should be controlled. The injection of the liquid sample to the sensor surface must be controlled in term of its volume as well as its flow rate. A syringe pump injection system for a single shot sample injection has been developed. However, the system lacked a continuous sample injection. In this study, a peristaltic-based pump has been developed. A motor stepper and appropriate motor driver allowed the system to works from a micro-step to full step speed. The injection system allowed one to control the volume as well as the flow rate. The developed system was able to feed a liquid sample to the QCM sensor surface with a wide range of flow rate. It was observed that the flow rate injection affected the QCM sensor to respond. Careful selection of the liquid flow rate was required to avoid an unintended effect on the QCM sensor. Using the developed system, we show that a minimum effect on the QCM sensor respond caused by the flow rate of the liquid injection can be achieved.