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251.
Gerhard Reuter 《植物养料与土壤学杂志》1999,162(1):97-105
Profile-morphological study of the ‘disharmonic’ polygenesis of Podzols Based on the relevant literature and his own research findings the author points out the diversity of soils designated as Podzols in the past and the present. Older Podzols which have passed through several phases of development (polygenesis) not infrequently show illuvial horizons with iron oxides and/or clay minerals which were obviously washed out earlier than the humus substances. This is demonstrated by photographs. Whereas previous attempts to explain these facts were based on changes in pedogenetic parameters (pH, redox potential, density) or vegetation (= harmonic development) the author suggests taking Holocene climatic changes into consideration (= disharmonic development). By analogy with the formation of clay-illuvial horizons of ‘Lessivé-Braunerden’ (so-called ‘Parabraunerde-Braunerden’ after AG Boden, 1994) on till and loess in Central Europe, which the author considers to be relict formations developed under the warm-humid climatic conditions of the Atlanticum, we can — in very sandy soils — assume a similar process of percolative sesquioxide-transfer during this period. If further investigations come to the conclusion that such transport of colloids took place without the participation of organic complex-forming substances this process should no longer be interpreted as a phase of podzolisation, but either attributed to lessivation or designated by a new pedogenetic term (ferralluviation, Ferralluvisol). 相似文献
252.
For the period 2003–2006, fructification of Norway spruce (Picea abies [L.] Karst.) was recorded at the Kranzberg forest site in Southern Germany by employing a crane with access to the canopy of more than 266 trees. For each tree, stem diameter and growth parameters were assessed annually as well as biomass of cones and seeds, number of seeds per cone, and proportions of empty seeds for a total of 371 trees with cone crop. Genotypes at 19 enzyme coding gene loci of 110 trees were included in the study of correlations between morphological and genetic traits. Re-scaling the observed values for a virtual pure Norway spruce stand of 1 ha, cone biomass including winged seeds (oven-dried at 38°C) varied between 706.8 kg/ha in 2006 (average value per tree was 3.6 kg) and values close to zero in 2005. Corresponding values for vegetative biomass increment of the coning trees in 2006 were 9,273.0 kg/ha and 10.8 kg/tree. A significant higher biomass investment was determined for dominant trees in terms of absolute cone mass as well as in terms of cone mass relative to vegetative biomass and fructification frequency. No trade-off effects in decreased vegetative biomass growth were found in the fructification year, compared to trees that did not grow cones. Although the dominant trees invested proportionally considerable biomass in cones, they showed no significant reduction in vegetative biomass growth. In the following year no decrease in vegetative growth was detected. Based on logistic regressions and homogeneity tests, respectively, significant genetic effect became evident with respect to the gene loci AAP-B and AAT-C concerning fructification probability in the year with maximum generative biomass investment. These and closely related loci also have been found to be indicative for growth and viability, respectively, in other species. 相似文献
253.
Hitoshi Ogawa Isao Yamada Kiyoshi Arai Kangetsu Hirase Kouichi Moriyasu Christian Schneider Gerhard Sandmann Peter Bger Ko Wakabayashi 《Pest management science》2001,57(1):33-40
A mode of action study of herbicidal diphenylpyrrolidinones was carried out through carotenoid analyses in intact Scenedesmus cells and by a cell‐free plant‐type phytoene desaturase assay using Escherichia coli transformants. A series of forty‐eight diphenylpyrrolidinones decreased the carotenoid content of Scenedesmus cells in the light and inhibited phytoene desaturase. The relationship between substituents at various positions and inhibition of phytoene desaturase is discussed. Using very active bleaching diphenylpyrrolidinones, a 10−5 M concentration affected neither the ζ‐carotene desaturase nor the protoporphyrinogen‐IX oxidase. Although some differences in their inhibitory activity were found between the in vivo and cell‐free assays, it is concluded that the compounds are essentially bleachers affecting carotenoid biosynthesis in plants. Enzyme kinetics studies with recombinant phytoene desaturase revealed a non‐competitive inhibition with respect to the substrate phytoene. A competition against the inhibitor was shown by the cofactor NADP+, suggesting an interaction of pyrrolidinones at the cofactor‐binding site of phytoene desaturase. © 2001 Society of Chemical Industry 相似文献
254.
255.
Eman Maher Zahran Amgad Albohy Amira Khalil Alyaa Hatem Ibrahim Heba Ali Ahmed Ebaa M. El-Hossary Gerhard Bringmann Usama Ramadan Abdelmohsen 《Marine drugs》2020,18(12)
Marine organisms and their associated microbes are rich in diverse chemical leads. With the development of marine biotechnology, a considerable number of research activities are focused on marine bacteria and fungi-derived bioactive compounds. Marine bacteria and fungi are ranked on the top of the hierarchy of all organisms, as they are responsible for producing a wide range of bioactive secondary metabolites with possible pharmaceutical applications. Thus, they have the potential to provide future drugs against challenging diseases, such as cancer, a range of viral diseases, malaria, and inflammation. This review aims at describing the literature on secondary metabolites that have been obtained from Scleractinian-associated organisms including bacteria, fungi, and zooxanthellae, with full coverage of the period from 1982 to 2020, as well as illustrating their biological activities and structure activity relationship (SAR). Moreover, all these compounds were filtered based on ADME analysis to determine their physicochemical properties, and 15 compounds were selected. The selected compounds were virtually investigated for potential inhibition for SARS-CoV-2 targets using molecular docking studies. Promising potential results against SARS-CoV-2 RNA dependent RNA polymerase (RdRp) and methyltransferase (nsp16) are presented. 相似文献
256.
Pätzold Stefan Hbirkou Christine Dicke Dominik Gerhards Roland Welp Gerhard 《Precision Agriculture》2020,21(3):569-588
Precision Agriculture - The spatial distribution and density of different weed species were monitored during a long-term survey over a period of 9 years on a 5.8 ha arable field... 相似文献
257.
Contents of polycyclic aromatic hydrocarbons (PAH) and their distribution pattern in soils with different contamination levels In order to study the PAH-contamination of soils in North Rhine Westfalia, soil samples were taken at different sites and analysed for six PAH. The sites were selected with regard to different forms of land use such as arable land and pastures in rural areas and gardens in urban areas and with regard to varying immission situations. The results are valued according to reference (RW) and test values (PW) of the Netherlands Guidelines for soil restoration. The reference values of these guidelines characterizing normal contents are regularly and in part distinctly exceeded for fluoranthene and benzo(a)pyrene at some sites (coking plant, alluvial meadow soils, allotment gardens, close to a highway). The check values which imply more exact investigations are only exceeded at the most contaminated site, a coking plant. The PAH patterns at the different sites investigated depend on the number and kind of PAH sources. PAH typical for motor vehicle emission (benzo(b)fluoranthene, benzo(g,h,i)perylene) are dominating in soils close to a highway, whereas at the cokery site fluoranthene can be found in higher concentrations than the other PAH. In alluvial river soils and in soils of allotment gardens the pattern is more uniform because of diffuse sources with decreasing contents in the order fluoranthene > benzo(a)anthracene > benzo(b) fluoranthene > benzo(g,h,i)perylene > benzo(a)pyrene > benzo(k)fluoranthene. As a guide substance for a first risk assessment benzo(a)pyrene is suitable, since its content shows a strong correlation to the sum of five other PAH. In order to characterize the background contamination of soils with PAH new reference values are proposed. 相似文献
258.
259.
Gerhard Weber 《Journal of pest science》1952,25(4):53-56
Zusammenfassung 1. Nebel- und Sprühgeräte eignen sich für generelle Bekämpfungsmaßnahmen gegen die Kirschfruchtfliege.2. Der DDT-Nebelwirkstoff ist trotz einmaliger Anwendung für die Dauer der Bekämpfungszeit ausreichend wirksam.3. Eine Vernebelung von DDT wirkte sich in Mischbeständen auf die Bekämpfung des Apfelwicklers anscheinend günstig aus.4. Bei keinem im Behandlungsgebiet verbliebenen oder auch versuchsweise eingesetzten Bienenvolk traten Schäden ein.5. Die wirkungsvolle Bekämpfung der Kirschfruchtfliege hatte eine natürliche Reife der Spätkirschen zur Folge, wodurch Angebot und Preis in einem für den Obstbauer günstigen Verhältnis blieb.6. Je nach dem Tragalter des Baumes entsprachen die Bekämpfungskosten dem Wert von 2–5 Pfund Kirschen! 相似文献
260.