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141.
The brown shrimp, Crangon crangon, is the most important target of the coastal crustacean fisheries in the German Bight. In order to evaluate the relation between the abundance of ovigerous females and larvae in spring and the recruitment success in autumn, we first analysed the seasonal appearance of ovigerous females and larvae from weekly samples throughout 2012. The spawning season in the German Bight extends over several months comprising multiple unsynchronized spawning events. The minimum shares of ovigerous females appeared in early autumn, and the highest shares in late winter bearing mostly early egg stages. We defined the putative start of the reproductive cycle for November when the frequency of ovigerous females started to increase. There was no distinct separation between winter and summer eggs, but a continuous transition between large eggs spawned in winter (the early spawning season) and batches of smaller eggs in spring and summer. Larval densities peaked in April/May. Consequently, regular annual larval surveys from 2013 to 2016 were scheduled for April/May and extended to six transects covering the inner German Bight. Ovigerous females were most abundant in shallow waters above the 20‐m isobaths, which also explained regional differences in abundance between the regions off North Frisia and East Frisia. No relation was obvious between the number of larvae in spring and recruited stock in autumn. Due to the short lifespan of C. crangon, the combination of various abiotic factors and predator presence seems to be the principal parameters controlling stock size. 相似文献
142.
Hentschel V Kranl K Hollmann J Lindhauer MG Böhm V Bitsch R 《Journal of agricultural and food chemistry》2002,50(23):6663-6668
The so-called "yellow pigment" content of durum wheat has been used for a long time as an indicator of the color quality of durum wheat and pasta products. For decades the chemical nature of these pigments has been assigned to carotenoids, mainly to the xanthophyll lutein and its fatty acid esters. The chemical composition of the yellow pigments of eight German durum wheat cultivars was studied. Grains were milled on a laboratory mill. Pigment extraction of millstream fractions was performed according to the optimized ICC standard method 152 procedure, and the chemical composition of the extract was analyzed by isocratic reversed phase high-performance liquid chromatography. all-trans-Lutein ranged from 1.5 to 4 mg kg(-1), and zeaxanthin was found in traces. No lutein esters and carotenes were detected. Surprisingly, the fraction of carotenoids of the complete yellow pigment content amounted to only 30-50% of the yellow pigment quantities, so there are still compounds in durum wheat not yet identified that contribute considerably to the yellow color of the grain extracts. The isolation and chemical identification of those pigments are under investigation. 相似文献
143.
Foliar-applied glyphosate substantially reduced uptake and transport of iron and manganese in sunflower (Helianthus annuus L.) plants 总被引:1,自引:0,他引:1
Eker S Ozturk L Yazici A Erenoglu B Romheld V Cakmak I 《Journal of agricultural and food chemistry》2006,54(26):10019-10025
Evidence clearly shows that cationic micronutrients in spray solutions reduce the herbicidal effectiveness of glyphosate for weed control due to the formation of metal-glyphosate complexes. The formation of these glyphosate-metal complexes in plant tissue may also impair micronutrient nutrition of nontarget plants when exposed to glyphosate drift or glyphosate residues in soil. In the present study, the effects of simulated glyphosate drift on plant growth and uptake, translocation, and accumulation (tissue concentration) of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were investigated in sunflower (Helianthus annuus L.) plants grown in nutrient solution under controlled environmental conditions. Glyphosate was sprayed on plant shoots at different rates between 1.25 and 6.0% of the recommended dosage (i.e., 0.39 and 1.89 mM glyphosate isopropylamine salt). Glyphosate applications significantly decreased root and shoot dry matter production and chlorophyll concentrations of young leaves and shoot tips. The basal parts of the youngest leaves and shoot tips were severely chlorotic. These effects became apparent within 48 h after the glyphosate spray. Glyphosate also caused substantial decreases in leaf concentration of Fe and Mn while the concentration of Zn and Cu was less affected. In short-term uptake experiments with radiolabeled Fe (59Fe), Mn (54Mn), and Zn (65Zn), root uptake of 59Fe and 54Mn was significantly reduced in 12 and 24 h after application of 6% of the recommended dosage of glyphosate, respectively. Glyphosate resulted in almost complete inhibition of root-to-shoot translocation of 59Fe within 12 h and 54Mn within 24 h after application. These results suggest that glyphosate residues or drift may result in severe impairments in Fe and Mn nutrition of nontarget plants, possibly due to the formation of poorly soluble glyphosate-metal complexes in plant tissues and/or rhizosphere interactions. 相似文献
144.
Tobias Würschum Hans Peter Maurer Sigrid Weissmann Volker Hahn Willmar L. Leiser 《Plant Breeding》2017,136(2):230-236
Genomic prediction has emerged as a powerful genomic tool to assist breeding of complex traits. In this study, we employed a population of 647 triticale doubled haploid lines derived from four families to assess the potential of this approach for triticale breeding. All lines were phenotyped for grain yield, thousand‐kernel weight, biomass yield, plant height, frost tolerance and Fusarium head blight resistance. The obtained prediction accuracies were moderate to high and consisted to varying degrees of within‐ and among‐family variance, in line with the different degrees of phenotypic differences between family means. The prediction accuracy within individual families also varied with the genetic complexity of the traits and was generally highest based on effect estimation with lines from the respective family, whereas the prediction accuracy decreased with decreasing relatedness among the families. Taken together, our results illustrate the potential of genomic prediction to increase selection gain in triticale breeding, but the composition of the training set is of utmost importance, and consequently, the implementation of this approach in applied breeding programmes is not straightforward. 相似文献
145.
Delphine Manka'abusi Dsir J. P. Lompo Christoph Steiner Mariko Ingold Edmund Kyei Akoto-Danso Steffen Werner Volker Hring George Nyarko Bernd Marschner Andreas Buerkert 《植物养料与土壤学杂志》2020,183(4):500-516
To quantify carbon (C) and nitrogen (N) losses in soils of West African urban and peri‐urban agriculture (UPA) we measured fluxes of CO2‐C, N2O‐N, and NH3‐N from irrigated fields in Ouagadougou, Burkina Faso, and Tamale, Ghana, under different fertilization and (waste‐)water regimes. Compared with the unamended control, application of fertilizers increased average cumulative CO2‐C emissions during eight cropping cycles in Ouagadougou by 103% and during seven cropping cycles in Tamale by 42%. Calculated total emissions measured across all cropping cycles reached 14 t C ha?1 in Ouagadougou, accounting for 73% of the C applied as organic fertilizer over a period of two years at this site, and 9 t C ha?1 in Tamale. Compared with unamended control plots, fertilizer application increased N2O‐N emissions in Ouagadougou during different cropping cycles, ranging from 37 to 360%, while average NH3‐N losses increased by 670%. Fertilizer application had no significant effects on N2O‐N losses in Tamale. While wastewater irrigation did not significantly enhance CO2‐C emissions in Ouagadougou, average CO2‐C emissions in Tamale were 71% (1.6 t C ha?1) higher on wastewater plots compared with those of the control (0.9 t C ha?1). However, no significant effects of wastewater on N2O‐N and NH3‐N emissions were observed at either location. Although biochar did not affect N2O‐N and NH3‐N losses, the addition of biochar could contribute to reducing CO2‐C emissions from urban garden soils. When related to crop production, CO2‐C emissions were higher on control than on fertilized plots, but this was not the case for absolute CO2‐C emissions. 相似文献
146.
Loess proportions in slope deposits have rarely been quantified, due to the lack of quantification methods. In this study, we used laser granulometry to analyze grain‐size distributions in slope deposits of a Buntsandstein landscape in central Germany. The consistent loess contents obtained from two independent models corroborate the validity of the calculated loess proportions and the applicability of the new R package EMMAgeo. Yet, some limitations in transferability need to be considered. 相似文献
147.
Jan Knorn Tobias Kuemmerle Volker C. Radeloff Alina Szabo Marcel Mindrescu William S. Keeton Ioan Abrudan Patrick Griffiths Vladimir Gancz Patrick Hostert 《Biological conservation》2012,146(1):204-212
The effectiveness of protected areas can diminish during times of pronounced socio-economic and institutional change. Our goals were to assess the effectiveness of Romanian protected areas at stemming unsanctioned logging, and to assess post-socialist logging in their surrounding landscapes, during a time of massive socio-economic and institutional change. Our results suggest that forest cover remained fairly stable shortly before and after 1990, but forest disturbance rates increased sharply in two waves after 1995 and 2005. We found substantial disturbances inside protected areas, even within core reserve areas. Moreover, disturbances in the matrix surrounding protected areas were even lower than inside protected area boundaries. We suggest that these rates are largely the result of high logging rates, triggered by rapid ownership and institutional changes. These trends compromise the goals of Romania’s protected area network, lead to an increasing loss of forest habitat, and more isolated and more fragmented protected areas. The effectiveness of Romania’s protected area network in terms of its ability to safeguard biodiversity is therefore most likely decreasing. 相似文献
148.
Johannes Bieser Armin Aulinger Volker Matthias Markus Quante 《Water, air, and soil pollution》2012,223(3):1393-1414
Benzo[a]pyrene (BaP) has been proven to be toxic and carcinogenic. Since 2010, the European Union officially established target values
for BaP concentrations in ambient air. In this study BaP concentrations over Europe have been modelled using a modified version
of the chemistry transport model Community Multiscale Air Quality (CMAQ) which includes the relevant reactions of BaP. CMAQ
has been run using different emission datasets for the years 1980, 2000, and 2020 as input data. In this study, the changes
in BaP concentrations between 1980 and 2020 are evaluated and regions which exceed the European annual target value of 1 ng/m3 are identified, i.e. the Po Valley, the Paris metropolitan area, the Rhine-Ruhr area, Vienna, Madrid, and Moscow. Additionally,
the impact of emission reductions on atmospheric concentrations of BaP is investigated. Between 1980 and 2000, half of the
BaP emission reductions are due to lower emissions from industrial sources. These emission reductions, however, only contribute
to one third of the total ground-level BaP concentration reduction. Further findings are that between 2000 and 2020, a large
part (40%) of the BaP concentration reduction is not due to changes in BaP emissions but caused by changes in emissions of
criteria pollutants which have an impact on the formation of ozone. 相似文献
149.
Nicola Tomasi Maria De Nobili Stefano Gottardi Laura Zanin Tanja Mimmo Zeno Varanini Volker Römheld Roberto Pinton Stefano Cesco 《Biology and Fertility of Soils》2013,49(2):187-200
The aim of this work is to evaluate the capability of tomato plants to use different Fe sources, such as Fe citrate, Fe phytosiderophores, and Fe complexed by a water-extractable humic substances (Fe-WEHS) also in relation to physiological and molecular adaptations induced by these complexes at the root level. Tomato plants acquired higher amounts of Fe from Fe-WEHS than from the other two sources and this phenomenon occurred only when the treatment lasted 24 h. The higher acquisition of Fe from Fe-WEHS than other sources depended on a reductive mechanism and on rhizosphere acidification and appeared to be due neither to a higher apoplastic loading nor to a higher resistance of WEHS to microbial degradation. Supply of the different Fe complexes to deficient plants induced a transient upregulation of Fe(III)-chelate reductase (LeFRO1) and Fe transporter genes, LeIRT1 and LeIRT2. In Fe-WEHS-fed plants, where a quicker and higher upregulation of these genes was evident, a coordination in the expression of LeFRO1, LeIRT1, and LeIRT2 genes occurred already after 1 h treatment when the amount of Fe acquired by the plants from the three sources was similar. Iron from Fe-WEHS could be efficiently acquired in a mixture of natural Fe complexes possibly occurring in the rhizosphere. This phenomenon is due to an altered expression of Fe uptake-related genes and to the root capacity to create favorable conditions for the micronutrient uptake into the rhizosphere. 相似文献
150.
Heussler VT Rottenberg S Schwab R Küenzi P Fernandez PC McKellar S Shiels B Chen ZJ Orth K Wallach D Dobbelaere DA 《Science (New York, N.Y.)》2002,298(5595):1033-1036
Parasites have evolved a plethora of mechanisms to ensure their propagation and evade antagonistic host responses. The intracellular protozoan parasite Theileria is the only eukaryote known to induce uncontrolled host cell proliferation. Survival of Theileria-transformed leukocytes depends strictly on constitutive nuclear factor kappa B (NF-kappaB) activity. We found that this was mediated by recruitment of the multisubunit IkappaB kinase (IKK) into large, activated foci on the parasite surface. IKK signalosome assembly was specific for the transforming schizont stage of the parasite and was down-regulated upon differentiation into the nontransforming merozoite stage. Our findings provide insights into IKK activation and how pathogens subvert host-cell signaling pathways. 相似文献