Untersuchungen an Samenglobulinen von Leguminosen IV. Disk-elektrophoretischer Vergleich der Globulinfraktionen einigerVicia-Arten

Для диск-электрофоре тического сравнения глобулинов семян различных видовVida кислая буферн ая система, в которой разделение протеино в происходит при pH 3,8, оказ алась более пригодно й, чем щелочная (раз-деление при pH 9,3). При применении к ислой буферной системы особенно важно поддержание ко нстантной температу ры, так как в этих условиях с понижением темпера туры появляются преи мущественно агрегаты легумина, сильно изменяющие эл ектрофореграмму. Исследованные образ цыV. faba не обнаружили замет ной изменчивости электрофореграмм гл обулинов. Обсуждаются причины этой констатации. Сущ ественные различня наблюдались между ра зными видамиVida. Однако, только для группыVida sativa можно было установ ить четкую корреляци ю электрофореграмм глобулинов с таксоно мическим подразделе нием рода.     

Metabolite transfer via enzyme-enzyme complexes

The concentrations of enzyme sites in cells are usually higher than the concentrations of cognate intermediary metabolites. Therefore metabolic pathways or substantial segments of pathways may proceed by the direct transfer of metabolites from one enzyme site to the next by means of enzyme-enzyme complex formation. This mechanism of metabolite transfer differs from that usually assumed where dissociation and random diffusion of metabolite through the aqueous environment is responsible for the transfer to the next enzyme site. Since the direct transfer mechanism does not involve the aqueous environment, the energetics of metabolite interconversion can differ from expectations based on aqueous solution data. Evidence is summarized suggesting that metabolite is transformed and transferred with equal facility everywhere in the direct transfer pathway.     

A high soil potential net nitrification was observed at 4 m depth: What are the driving factors?

Studies about nitrogen (N) mineralization and nitrification in deep soil layers are rare because N processes are considered to occur mainly in topsoil that hosts active and diverse microbial communities. This study aimed to measure the soil potential net N mineralization (PNM) and nitrification (PNN) down to 4 m depth and to discuss factors controlling their variability. Twenty-one soil cores were collected at the Restinclières agroforestry experimental site, where 14-year-old hybrid walnut trees were intercropped with durum wheat. Soil cores were incubated in the dark in the laboratory at both 6 and 25°C. The soil was a deep calcic fluvisol with a fluctuating water table. It featured a black layer that was very rich in organic matter and permanently water saturated at depths between 3.0 and 4.0 m. The mean soil mineral N content was 3 mg N kg⁻¹ soil in the upper 0.0–0.2 m layer, decreasing until a depth of 2 m and increasing to the maximum value of 25.8 mg N kg⁻¹ soil in the black layer. While nitrate (NO₃⁻) was the dominant form of mineral N (89%) in the upper 0.0–0.2 m layer, its proportion progressively decreased with depth until ammonium (NH₄⁺) became almost the only form of mineral N (97%) in the saturated black layer. Laboratory soil incubation revealed that PNM and PNN occurred at all depths, although the latter remained low at 6°C. The soil nitrate content in the black layer was multiplied by 48 times after 51 days of incubation at 25°C, whereas it was almost inexistent at the sampling date. While the soil total N, the pH and the incubation temperature explained 84% of the variation in PNM, only 29% of the percent nitrification variance was explained by the incubation temperature (T_inc) and the soil C-to-N ratio. These results point out the necessity to consider soil potential net N mineralization and nitrification of deep soil layers to improve model predictions.     

Effect of nitrogen and potassium fertilizer on growth,herbage and oil yield of irrigated palmarosa (Cymbopogon martinii [roxb.] wats. var. motia burk) in a semi-arid tropical climate

The world's agricultural production is increasing by 1 to 2 per cent annually and has been enough to satisfy the growing world population's need for food. Breeding, fertilisation and crop protection have decidedly contributed to that progress in productivity. But since the 1960s, agriculture has been more and more conceived by the public as an environment-contaminating industry. The public is concerned about water contamination with nitrate as a result of the use of fertilisers, and about harmful effects of chemical plant protection products on soil, water, air, animals and wild plants. The public discussion has not remained without consequences. Sustainability of development has become a central political objective in all spheres of social life, and in all world regions. Sustainable development concerns economic, ecological as well as social objectives, and is also the guideline for a renovation of agriculture. Any concepts and strategies integrating environmental aspects into agricultural production are linked with the objective of sustainable development. Discussion on sustainable agriculture has become more concrete on the basis of the Brundtland Report and Agenda 21 , as well as the various follow-up meetings of the 1992 Conference of Rio. Although efforts towards sustainable development in agriculture encounter widespread scepticism, clear progress is to be noted since that discussion has intensified. Farmers have paid more attention to new farming practices. Environmental aspects now play an important role when extension services advise farmers on fertilisation and crop protection. Research has contributed essentially to the change in agriculture towards sustainable production. Sustainability in agriculture has also been expressed in new legal regulations. Principles of good professional practice in applying fertilisers, as it is required by the Fertilisers Act from the year 1989, have been spelled out more clearly in a legal regulation issued on 26 January 1996 (Federal Law Gazette part I of 06 February 1996, p. 118). Principles of good professional practice in crop protection were published in Bundesanzeiger (Federal Gazette) No. 220 a of 21 November 1998. Principles of integrated crop protection were first discussed by representatives of agriculture, environment protection offices and researchers at a workshop at Biologische Bundesanstalt für Land- und Forstwirtschaft (BBA, Federal Biological Research Centre for Agriculture and Forestry) in Kleinmachnow on 23° March 2000. The debate on sustainability centres around the aspects of economic and social efficiency of measures taken, and their effects on the environment. The following article deals with some basic aspects of efficiency on the one hand, and effects/emission on the environment on the other, of fertilisers and crop protection products as important input factors in agriculture. Crop husbandry always is an interference with nature. The Lüneburger Heide cropping region is a memorial of ecologically out-dated land management. Today, sustainable and at the same time efficient agriculture can only be realised with modern methods based on sound knowledge. This includes mineral fertilisation and chemical crop protection. Cropping permanently draws nutrients from the soil-plant system. They have to be refilled by fertilisation. If no fertilising measures are taken at all, the humus layer of the soil declines and soil degrades. The decline in fertility will result in yield losses of between 70 and 90%. In contrast, combination of organic and mineral fertilisers has continually added to soil fertility. This is reflected in the humus content of the soil, which is by about a quarter higher than it was a hundred years ago. Farmers resorting solely to mineral fertilisation produce yields lower by 5-10% than those combining mineral and organic fertilisers. If only organic fertilisers are used, this may reduce yields by between 10 and 40%, depending on the site. Unwanted side-effects of fertilisation (such as leaching of nitrates) may be reduced to a tolerable level by precise input of nutrients, improved methods such as precise fertiliser input depending on the condition of certain field patches, and by integrated crop protection, which relies on synergetic effects of various measures. Germany has for these reasons witnessed a relaxation of environmental pressure from excessive nutrient input. If crop protection measures were abandoned, pests and diseases would reduce yields by between 40 and 80 per cent. Our own trials about energy input-output proportions have shown a ratio of 1:4.6 with use of fertilisers (100kg N/ha), and a ratio of 1:8.6 with use of fertiliser and chemical plant protection products. The risk potential of modern chemical plant protection products has permanently decreased over the past few decades and is generally about one tenth of the values of 15 years ago. Integrated crop protection, which combines various methods of crop protection and reduces the use of chemical crop protection products to a necessary minimum, is the "optimal solution for the future" and "contributes to the sustainability of agriculture", as it is said in the Agenda 21 programme adopted by the 1992 environmental conference in Rio.     

Establishment success in a forest biodiversity and ecosystem functioning experiment in subtropical China (BEF-China)

Experimental forest plantations to study biodiversity–ecosystem functioning (BEF) relationships have recently been established in different regions of the world, but subtropical biomes have not been covered so far. Here, we report about the initial survivorship of 26 tree species in the first such experiment in subtropical China. In the context of the joint Sino–German–Swiss Research Unit “BEF-China,” 271 experimental forest plots were established using 24 naturally occurring tree species and two native commercial conifers. Based on the survival inventories carried out in November 2009 and June 2010, the overall survival rate was 87 % after the first 14 months. Generalized mixed-effects models showed that survival rates of seedlings were significantly affected by species richness, the species’ leaf habit (deciduous or evergreen), species identity, planting date, and altitude. In the first survey, seedling establishment success decreased with increasing richness levels, a tendency that disappeared in the second survey after replanting. Though evergreen species performed less well than deciduous species with establishment rates of 84 versus 93 % in the second survey, their planting success exceeded the general expectation for subtropical broad-leaved evergreen species. These results have important implications for establishing mixed-species plantations for diversity conservation and improvement of ecosystem functioning in the Chinese subtropics and elsewhere. Additional costs associated with mixed-species plantations as compared to conventional plantations also demonstrate the potential of upscaling BEF experiments to large-scale afforestation projects.     

Occurrence of Agriotes wireworms in Austrian agricultural land

Agriotes wireworms (Coleoptera: Elateridae) are abundant soil-dwelling herbivores which can inflict considerable damage to field crops. In Europe up to 40 species occur, differing in their ecology and pest status. Their distribution in the larval stage, however, has rarely been assessed because of the considerable effort in collecting wireworms and the difficulties in identifying them to species-level. Here, we examined the occurrence of Agriotes wireworms in Austrian agricultural land with regard to their association with climatic and soil parameters. Using a molecular identification system, 1348 field-collected larvae from 85 sites were identified to species-level. Three species, Agriotes obscurus, Agriotes brevis, Agriotes ustulatus, and two that could not be discerned molecularly (Agriotes lineatus and Agriotes proximus), were assigned to two ecological groups: (i) A. brevis/A. ustulatus, found in areas with a warmer, drier climate and alkaline soils, and (ii) A. obscurus/A. lineatus/proximus which occur mainly at higher altitude characterised by lower temperatures, higher precipitation and acidic, humus-rich soils. Agriotes sputator was abundant throughout Austria, confirming its euryoecious nature. Only one larva of Agriotes litigiosus was found, prohibiting further analysis. These data contribute to a characterisation of species-specific traits in Agriotes larvae in agricultural land, an important prerequisite to develop efficient control strategies for these wireworms.     

Clinical ocular findings in cows with malignant catarrhal fever: ocular disease progression and outcome in 25 cases (2007-2010)

Objective To describe the ocular clinical signs in a group of cows diagnosed with sheep associated malignant catarrhal fever (MCF), and to investigate a possible correlation between the severity and progression of certain typical clinical signs and disease outcome. Procedure This prospective study involved cows diagnosed with MCF between 2007 and 2010, and included cows enrolled in a larger clinical trial. Signalment of affected cows, presence and progression of ocular lesions, as well as disease outcome were recorded. Cows were divided into two groups based on the disease outcome: (1) survival and (2) nonsurvival. The degree of corneal edema at first examination was statistically compared between groups. The progression of corneal edema, uveitis and the examining ophthalmologists’ subjective assessment of disease progression between the first and last examination were also compared between groups. Results Twenty‐five cows (22 F, 3 M) of six different breeds and one mixed breed were included. Median age was 21 months (range 8–113). Ten cows survived, 13 cows were euthanized, and two died. No statistical association was identified between the degree of corneal edema at the first examination and the disease outcome. Deterioration of corneal edema was not noticed in any of the surviving animals. Anterior uveitis improved in all 10 surviving cows. Conclusions The degree of corneal edema at first examination had no prognostic value for the disease outcome. The results of this study suggest that the progression of corneal edema correlates well with disease outcome, and that nonimprovement of uveitis is a bad prognostic sign.     

Effects of management intensity and soil chemical properties on <Emphasis Type="Italic">Rumex obtusifolius</Emphasis> in cut grasslands in Lower Austria

Rumex obtusifolius (broad-leaved dock) is a widely distributed weed in managed grasslands and is an indicator for excessive grassland management. Especially in organic farming, its control is highly labour and energy intensive. The effects of management extensification on R. obtusifolius were investigated by on-farm trials with reduced cutting frequencies and manuring amounts from 2004 to 2006 at three sites in Lower Austria. The sites distinctly differed in their nutrient availabilities (LiCl-extract; Ca: ranged from 1,380 to 2,062 mg/kg DM, Mg: 211–611 mg/kg, P: 4–40 mg/kg, K: 57–334 mg/kg). At one site reduced management intensity had a significant decreasing effect on R. obtusifolius infestation, whereas at the other sites no effect was observed. Consequently, extensification as a measure for controlling this weed can be effective under certain conditions. Soil analyses indicated that Ca and Mg concentrations were negatively correlated to R. obtusifolius density, and the site where infestation declined under reduced management was characterised by abundant Ca and Mg in the topsoil. K showed a weak positive correlation with plant density development and P was not related to R. obtusifolius. According to the literature, an abundance of Ca and Mg in the soil could reduce the competitiveness of the species. Consequently, high concentrations of these nutrients might enhance the probability for an effective R. obtusifolius control by management extensification. Further research is required to clarify the influence of Ca and Mg on the competitiveness of R. obtusifolius, and may lead to recommendations for the management of this weed.     

Indicator development in sustainability impact assessment: balancing theory and practice

In this article, the development and operationalisation of forestry-wood chain indicators within the frame of sustainability impact assessment are discussed. The analytical framework follows a distinction between indicator definition and selection in a first phase, and a second operational phase of indicator application in terms of interconnecting material flows, calculation of chain performance and utilisation within evaluation components. A clear boundary drawing effort in terms of the development of indicator definitions, related subclasses, and measurement units as well as the creation of conversion factors between indicator values and individual chain stages supports this. Economic, social and environmental indicators have to respond to data collection needs on individual process levels (that correspond to sub-divisions of the forestry-wood chain). For the usage of indicators within evaluation tools, a functional hierarchy has to be provided that supports clear preference elicitation as well as information on related externalities. In total, this paper aims at demonstrating an enhanced spectrum in the use of sustainability indicators, and the challenges that arise from a developing and applying multi-functional indicators in sustainability impact assessment.     

Network context and selection in the evolution to enzyme specificity

Enzymes are thought to have evolved highly specific catalytic activities from promiscuous ancestral proteins. By analyzing a genome-scale model of Escherichia coli metabolism, we found that 37% of its enzymes act on a variety of substrates and catalyze 65% of the known metabolic reactions. However, it is not apparent why these generalist enzymes remain. Here, we show that there are marked differences between generalist enzymes and specialist enzymes, known to catalyze a single chemical reaction on one particular substrate in vivo. Specialist enzymes (i) are frequently essential, (ii) maintain higher metabolic flux, and (iii) require more regulation of enzyme activity to control metabolic flux in dynamic environments than do generalist enzymes. Furthermore, these properties are conserved in Archaea and Eukarya. Thus, the metabolic network context and environmental conditions influence enzyme evolution toward high specificity.