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121.
Anna A. Filatenko Karl Hammer Sulaiman Al Khanjari Andreas Buerkert 《Genetic Resources and Crop Evolution》2010,57(8):1135-1139
Due to its geographic position on the northeastern tip of the Arabian Peninsula and its sea trade relationships with Asia,
East Africa and the Middle East, Oman has for millennia been at the cross-roads of inter-regional exchange of cultivated plants.
This is reflected in recent findings of new cultivars of banana (Musa spp.) and wheat (Triticum spp.) in remote oases of the Hajar Mountains in northern Oman. Material collected in 2003 and 2004 contained six new botanical
varieties of wheat which are described here. One of them belongs to the tetraploid T. aethiopicum, the others are hexaploid. 相似文献
122.
123.
Martin ten Huf Thorsten Reinsch Christof Kluß Christoph Essich Reiner Ruser Caroline Buchen-Tschiskale Andreas Pacholski Heinz Flessa Hans-Werner Olfs 《植物养料与土壤学杂志》2023,186(4):451-463
Background
There is a great need for simple and inexpensive methods to quantify ammonia emissions in multi-plot field trials. However, methods that meet these criteria have to be thoroughly validated. In the calibrated passive sampling approach, acid traps placed in the center of quadratic plots absorb ammonia, enabling relative comparisons between plots. To quantify ammonia emissions, these acid trap samplings are scaled by means of a transfer coefficient (TC) obtained from simultaneous measurements with the dynamic tube method (DTM). However, dynamic tube measurements are also comparatively costly and time-consuming.Aims
Our objective was to assess the best practice for using calibrated passive sampling in multi-plot field trials. One particular challenge in such experiments is to evaluate the influence of ammonia drift between plots.Methods
In a series of eight multi-plot field trials, acid traps and DTM were used simultaneously on all plots to measure ammonia emissions caused by different slurry application techniques. Data obtained by both methods were correlated, and the influence of the ubiquitous ammonia background on both methods was evaluated by comparing net values, including the subtraction of the background with gross values (no background subtraction). Finally, we provide recommendations for calculating a TC for calibrating relative differences between plots, based on simultaneous acid trap and dynamic tube measurements on selected plots.Results
Treatment mean values obtained by both methods correlated well. For most field trials, R2 values between 0.6 and 0.8 were obtained. Ammonia background concentrations affected both methods. Drift between plots contributed to the background for the acid traps, whereas the contamination of the chamber system might have caused the background for the DTM. Treatments with low emissions were comparatively more affected by that background.Conclusion
For a robust application of calibrated passive sampling, we recommend calculating the TC based on a treatment with high ammonia emissions, reducing the relative influence of the ubiquitous ammonia background. 相似文献124.
Julia K. Denzler Andreas Weidenhiller Michael Golser 《Wood Science and Technology》2013,47(4):749-761
The sawmilling industry stores and measures logs with bark in order to maximize efficiency, quality conservation and preservation. However since billing is based on the diameter under bark, it is necessary to differentiate between bark areas and wood areas automatically or via manual assignment. This paper compares different methodologies to automatically differentiate between these areas based on colour images of the log surface of two species, spruce and pine. Additionally, the performance of the different methodologies is evaluated using the proportion of correctly detected bark areas, correctly detected wood areas and the total amount of detected bark and wood areas. In the end, an algorithm taking into account colour and texture information was found to perform well on both species. Based on a larger dataset, this methodology has the potential to detect the diameter under bark based on measurements of logs with bark. 相似文献
125.
Andreas Leclerque Polina V. Mitkovets Ana-Cristina Fatu Christina Schuster Regina G. Kleespies 《Journal of pest science》2013,86(1):107-113
Wireworms, the polyphagous larvae of click beetles belonging to the genus Agriotes (Coleoptera: Elateridae), are severe and widespread agricultural pests affecting numerous crops. Biological control agents and methods for this general pest are highly solicited. In a screening for microbial Agriotes pathogens, an intracellular bacterium and a mitosporic fungus were isolated. Phylogenetic analysis based on ribosomal RNA operon sequences of both micro-organisms corroborated their previous morphology-based taxonomic classification. The bacterial pathogen has been assigned to the taxonomic genus Rickettsiella (Gammaproteobacteria) wherein it represents a new pathotype, ‘Rickettsiella agriotidis’, that appears most closely related to subjective synonyms of the nomenclatural type species, Rickettsiella popillae. The fungal pathogen has been shown to belong to the form-species Beauveria bassiana, i.e., an obligate anamorph related to the genus Cordyceps (Ascomycota: Hypocreales). Furthermore, the B. bassiana strain from Agriotes has been shown to be potentially susceptible to identification by gIi-diagnosis, i.e., a diagnostic method making use of the strain-specific presence of self-splicing group-I introns within the ribosomal RNA operons of certain hyphomycetous fungi. 相似文献
126.
Chalathon Choocharoen Antonia Schneider Andreas Neef Pavlos Georgiadis 《Small-Scale Forestry》2013,12(2):193-213
This study examines the potential of cardamom for poverty alleviation and sustainable rural development under conditions of increased resource scarcity in the uplands of northern Laos. Drawing on both qualitative and quantitative fieldwork in Luang Namtha province, the supply chain of cardamom is identified and the socio-economic opportunities for collectors and growers are examined. Rising demand in neighbouring countries, particularly China, provide sound income opportunities for all actors in the cardamom supply chain. Growing improved varieties has become a boon for farmers endowed with relatively large land areas with suitable agro-ecological conditions. However, land-poor and landless collectors of wild cardamom are facing increasing difficulties due to overharvesting, lower prices offered by middlemen, and the rapid conversion of remaining forests into monoculture plantations, especially rubber, which has reduced the natural habitat of cardamom and other non-timber forest products. The major policy implication is that protecting the remaining natural and secondary forests—for instance through making use of evolving international support mechanisms for community-based forest protection, including REDD-plus—will not only be of benefit for biodiversity conservation and climate change mitigation, but would also enhance the livelihoods of the poorest groups in the uplands of northern Laos. 相似文献
127.
Klara Cecilia Gunnarsen Lars Stoumann Jensen Beatriz Gmez-Muoz Minik Thorleif Rosing Andreas de Neergaard 《植物养料与土壤学杂志》2019,182(5):846-856
Rock flour (RF) is a fine‐grained material produced naturally by glacial movement and resulting bedrock abrasion. In Greenland fluvial transported RF from the inland ice sheet sediments in riverbeds and marine outflows. This fine‐sized RF (50% < 9.8 µm) has a high reactivity and may therefore potentially be used to rejuvenate nutrient poor soils and provide nutrients to plants. The aim of this study was to evaluate the ability of a RF from Greenland to supply P, K, Mg, and S to plants. A double‐pot system was used, in which ryegrass (Lolium perenne L.) could take up nutrients from both a hydroponic solution and a soil‐compartment with or without RF amendment; a soil mixture or pure sand was used in the soil‐compartment to estimate RF‐soil interaction effects. Omission of single nutrients from the hydroponic solution allowed assessment of which nutrients the RF in the soil‐compartment was able to supply. Ryegrass biomass was harvested four times during 62 days. We found that RF could supply K continuously to plants grown in soil or sand, but insufficient to fully circumvent K deficiency. During 62 days 5.8% and 4.3% of the applied K from RF was accumulated in the aboveground plant tissue in soil and sand, respectively. Mg was supplied from RF to plants in sand, but no significant effects were observed in soil, possibly due to background soil Mg availability. The amounts of P and S supplied to plants were insignificant. These results indicate the potential of Greenland RF to act as a slow release K and Mg fertilizer. 相似文献
128.
Organic geochemical parameters for estimation of petrogenic inputs in the coastal area of Kavala City,Greece 总被引:1,自引:0,他引:1
Anna Grigoriadou Jan Schwarzbauer Andreas Georgakopoulos 《Journal of Soils and Sediments》2008,8(4):253-262
Background, aims, and scope Sediments and soils in coastal areas are frequently polluted by anthropogenic contaminants as the result of both riverine
or terrestrial discharge and autochthonic marine emissions. In order to determine petrogenic contamination in the coastal
industrial area of Kavala City in northern Greece, a combination of polycyclic aromatic hydrocarbon (PAH) and organic geochemical
petroleum biomarker analyses has been performed on marine and freshwater sediments as well as soils.
Materials and methods Soils, freshwater, and marine sediments have been treated by standard extraction methods. The dried and desulphurized sample
extracts have been fractionated by column chromatography, followed by addition of surrogate standards. Qualitative and quantitative
data were obtained by gas chromatograph connected with a flame ionization and electron capture detector (GC-FID/ECD) and by
GC linked to a mass spectrometer (GC/MS), whereas identification of compounds was based on EI+-mass spectra and gas chromatographic retention times. Quantitative data were obtained by integration of specific ion chromatograms.
Results The total PAH concentrations measured in the area varied highly, showing different levels from 18 up to 318,000 ng g−1 dry weight (dw). Several PAH ratios, as well as the ratio of pristane (Pr) to phytane (Phyt), have been considered. Out of
39 samples, 22 revealed a specific distribution of hopane fingerprints indicating petrogenic input. Finally, in numerous samples,
the ratio of 17α(H)-22,29,30-trisnorhopane (Tm) and 18α(H)-22,29,30-trisnorhopane (Ts) was calculated, as well as the ratio
of 22S-17α(H),21β(H)-30 homohopane (αβC31-hopane 22S) and 22R-17α(H),21β(H)-30 homohopane (αβC31-hopane 22R).
Discussion Based on the specific PAH ratios, a group of samples was clearly characterized to be contaminated dominantly by combustion-derived
emissions, whereas a second group of samples exhibited mixed influence from petrogenic and pyrogenic PAHs. On the other hand,
the exhibition of specific hopane fingerprints in many samples indicates a direct petrogenic input. Finally, the values of
the ratio of Tm/(Ts + Tm) and of αβC31-hopanes 22S/(22S+22R)-isomer demonstrated an input of highly mature organic matter that has to be clearly attributed to petroleum-derived
contamination, while the ratio of Pr/Phyt showed that most samples exhibited an input of organic matter.
Conclusions The coastal area of Kavala is strongly affected by anthropogenic contaminants. Petrogenic emissions were pointed out firstly
by PAH analyses that separated dominantly pyrogenic contaminated sites from areas affected by both pyrogenic and petrogenic
emissions. However, analyses of organic geochemical biomarkers revealed a much higher sensitivity in identifying petroleum-derived
contaminations and were successfully used to differentiate several petrogenic contaminations in the marine and terrestrial
samples.
Recommendations and perspectives Based on this study, it was recommended to use a complementary approach of source-specific substances to successfully characterize
petrogenic emissions. Generally, a PAH-based source identification of petrogenic versus pyrogenic contaminations should be
combined with petroleum biomarker analysis. PAH and biomarker ratios as well as individual biomarker fingerprints revealed
a more comprehensive view on the quality and quantity of petrogenic emissions in sediments and soils. 相似文献
129.
Cooper KA Campos-Giménez E Jiménez Alvarez D Rytz A Nagy K Williamson G 《Journal of agricultural and food chemistry》2008,56(1):260-265
Chocolate is often labeled with percent cocoa solids content. It is assumed that higher cocoa solids contents are indicative of higher polyphenol concentrations, which have potential health benefits. However, cocoa solids include polyphenol-free cocoa butter and polyphenol-rich nonfat cocoa solids (NFCS). In this study the strength of the relationship between NFCS content (estimated by theobromine as a proxy) and polyphenol content was tested in chocolate samples with labeled cocoa solids contents in the range of 20-100%, grouped as dark (n = 46), milk (n = 8), and those chocolates containing inclusions such as wafers or nuts (n = 15). The relationship was calculated with regard to both total polyphenol content and individual polyphenols. In dark chocolates, NFCS is linearly related to total polyphenols (r2 = 0.73). Total polyphenol content appears to be systematically slightly higher for milk chocolates than estimated by the dark chocolate model, whereas for chocolates containing other ingredients, the estimates fall close to or slightly below the model results. This shows that extra components such as milk, wafers, or nuts might influence the measurements of both theobromine and polyphenol contents. For each of the six main polyphenols (as well as their sum), the relationship with the estimated NFCS was much lower than for total polyphenols (r2 < 0.40), but these relationships were independent of the nature of the chocolate type, indicating that they might still have some predictive capabilities. 相似文献
130.
Sirisakulwat S Nagel A Sruamsiri P Carle R Neidhart S 《Journal of agricultural and food chemistry》2008,56(22):10727-10738
Pectins, recovered from the peels of four mango ( Mangifera indica L.) cultivars by mimicking industrial techniques, were evaluated in terms of yield, composition, macromolecular properties, and technofunctional quality. Freeze-dried peels of mature-green fruits, after major mesocarp softening, and at full ripeness were extracted using hot acid. The pectins were precipitated in propan-2-ol and their crude yields quantified as alcohol-insoluble substance. Like apple pomace, the dried peels provided hardly acetylated (DAc < 6.3%) rapid-set to ultrarapid-set high-methoxyl pectins at starch-adjusted yields of 11-21 g/100 g. However, despite similar high molecular weight fractions and galacturonic acid/rhamnose ratios, their average molecular weight was markedly reduced by a characteristic, almost monodisperse fraction of 16000-19000. Expanded galactans, indicated by galactose/rhamnose ratios of 15-24 mol/mol, probably represented arabinogalactan side-chain fragments withstanding hot-acid extraction at pH 1.5 and 2.0, as implied by arabinose/galactose ratios of 8-15 and 33-56 mol/100 mol, respectively. Limited galacturonic acid contents made the mango peel pectins less valuable than commercial apple pectins with regard to gelling capacity and thickening properties. Whereas starch and matrix glycan fragments almost completely degraded during ripening, depolymerization of pectins and galactans was insignificant. Technofunctional properties, modulated by extraction at different pH values, were ascribed to structural differences influencing macromolecular entanglements. 相似文献