12 research outputs found

    Betreuungsformate im Grundschulalter: Angebote und Kosten. DJI-Kinderbetreuungsreport 2021. Studie 3 von 7

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    Der vorliegende Report enthält [...] Ergebnisse der Erhebung im Rahmen der DJI-Kinderbetreuungsstudie (KiBS) aus dem Jahr 2020. [...] Der Fokus liegt dabei auf der Betreuungssituation der Kinder, den Angeboten, die durch die besuchten Einrichtungen unterbreitet werden sowie den Kosten für die Betreuung. (DIPF/Orig.

    Investigations of sinapic acid ester suppression and expression of resveratrol in transgenic rapeseed (Brassica napus L.)

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    Die Verwendung von Rapsprotein in der Human- und Tierernährung wird durch phenolische Verbindungen wie Sinapinsäureester erheblich limitiert, da sie infolge ihrer antinutritiven Eigenschaften die Qualität von Lebens- und Futtermitteln beeinträchtigen. Die Sinapinsäure- Glucosyltransferase (SGT) stellt das zentrale Enzym der Sinapinsäureester-Biosynthese im Samen dar. Mit Hilfe der Agrobakterium vermittelten Transformation sollte unter Verwend-ung des SGT-Doppelstrang-RNA-Interferenz (SGT-ds-RNAi) Konstruktes pLH-SGT-GUS die Aktivität der Sinapinsäure-Glucosyltransferase im Samen supprimiert werden. Die Variabilität des Gesamt-Sinapinsäureestergehaltes (Gesamt-SAE) in den im Gewächshaus angezogenen T1-Pflanzen lag zwischen 2,84 mg/g und 10,61 mg/g . In den Kontrollen (n=30) wurden dagegen Gehalte zwischen 7,28 und 10,33 mg/g Samen ermittelt. Der Gehalt an Sinapoylglucose war hoch signifikant korreliert mit dem Sinapingehalt (rs=0,76**) sowie mit den bislang nicht identifizierten Sinapinsäureestern (rs=0,92**) und dem Gesamt-SAE-Gehalt (rs=0,91**). Zwischen den Transformanden und den Kontrollen lagen hinsichtlich wichtiger agronomischer Merkmale, wie Öl-, Protein- und Glucosinolatgehalt sowie Fettsäure-zusammensetzung keine signifikanten Unterschiede vor. In einer homozygoten T2-Pflanze konnte der Sinapinsäureestergehalt, im Vergleich zu der Kontrollpflanze mit den niedrigsten Gesamt-SAE-Gehalten (7,48 mg/g), um 76% auf 1,83 mg/g reduziert werden. In dieser T2-Pflanze war der Sinapingehalt um 72% auf 2,66 mg/g Samen und die bislang nicht identifizierten Sinapinsäureester sowie der Sinpoylglucosegehalt um 100% auf 0 mg/g Samen reduziert.Ein weiteres interessantes Biomolekül für eine gentechnische Veränderung der Samenqualität ist das Phytoalexin Resveratrol, welches natürlicherweise nicht im Raps vorkommt. Durch seine antioxidative und anticancerogene Wirkung kann es gesundheitsfördernd wirken. Im zweiten Teil der Arbeit sollte das Gen der Stilbensynthase (VST1) aus Vitis vinifera unter Kontrolle eines samenspezifischen Promoters (pPSty5 Konstrukt) in Verbindung mit dem o.g. pLH-SGT-GUS Konstrukt in Agrobakterium vermittelten Co-Transformationsversuchen im Raps zur Expression gebracht werden. Die im Gewächshaus angezogenen T1-Pflanzen akkumulierten Resveratrol im Samen in seiner glycosidischen Form. Drei T1-Pflanzen mit den höchsten Resveratrolglucosidgehalten (308 361µg/g) wurden für die weitere Charakterisierung ausgewählt. Zwischen den Transformanden und den Kontrollen lagen hinsichtlich wichtiger agronomischer Merkmale, wie Öl-, Protein- und Glucosinolatgehalt sowie Fettsäurezusammensetzung keine signifikanten Unterschiede vor. In einer homozygoten T2-Pflanze war der Resveratrolglucosidgehalt mit 424 µg/g am höchsten. Der Gesamt-SAE-Gehalt war in dieser Pflanze auf 1,30 mg/g reduziert, was verglichen mit der niedrigsten Kontrollpflanze (7,48 mg/g) einer relativen Gesamt-Sinapinsäureesterreduktion von 83% entspricht

    Evaluating biological containment strategies for pollen-mediated gene flow

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    Several biological containment methods have been developed to reduce pollen dispersal; many of them only have a proof of concept in a model plant species. This review focuses on biological containment measures which were tested for their long-term efficiency at the greenhouse or field scale level, i.e. plastid transformation, transgene excission, cleistogamy and cytoplasmic male sterility (CMS). Pollen-mediated gene transfer in transplastomic tobacco could occur at very low frequencies if the predominant mode of inheritance is maternal. Transgene excision from tobacco pollen can be made highly efficient by coexpression of two recombinases. For cleistogamous oilseed rape it was shown that some flowers were partially open depending on genotypes, environment and recording dates. Reports on the stability of CMS in maize and sunflower indicated that there is a high variability for different genotypes under different environmental conditions and over successive years. But for both crop types some stable lines could be selected. These data demonstrate that the biological containment methods discussed are very promising for reducing gene flow but that no single containment strategy provides 100% reduction. However, the necessary efficiency of biological containment methods depends on the level of containment required. The containment level may need to be higher for safety purposes (e.g. production of special plant-made pharmaceuticals), while much lower containment levels may already be sufficient to reach coexistence goals. It is concluded that where pollen-mediated gene flow must be prevented altogether, combinations of complementary containment systems will be required

    Influence of Air Temperature on the Stability of Cytoplasmic Male Sterility (CMS) in Maize (Zea mays L.)

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    Cytoplasmic male sterility (CMS) is a maternally inherited trait that suppresses the production of viable pollen. CMS is a useful biological tool for containment strategies to reduce or prevent gene flow and cross-pollination to facilitate coexistence of genetically modified (GM) and non GM-crops in cases where it is required. CMS is reversible and can restore to fertility in the presence of nuclear restorer genes (Rf-genes) and by environ- mental impacts. The aim of this study was to investigate the influence of air temperature on the stability of CMS maize hybrids under defined greenhouse conditions. Three CMS maize hybrids were grown in three different temperature regimes. Tassel characteristics, pollen production, and fertility were studied. The CMS stability was high in hot air tempera- tures and decreased in lower temperatures. The extent of these phenomena was dependent on the CMS maize genotype and should be known before using CMS for coexistence purposes.Cytoplasmic male sterility (CMS) is a maternally inherited trait that suppresses the production of viable pollen. CMS is a useful biological tool for containment strategies to reduce or prevent gene flow and cross-pollination to facilitate coexistence of genetically modified (GM) and non GM-crops in cases where it is required. CMS is reversible and can restore to fertility in the presence of nuclear restorer genes (Rf-genes) and by environmental impacts. The aim of this study was to investigate the influence of air temperature on the stability of CMS maize hybrids under defined greenhouse conditions. Three CMS maize hybrids were grown in three different temperature regimes. Tassel characteristics, pollen production, and fertility were studied. The CMS stability was high in hot air temperatures and decreased in lower temperatures. The extent of these phenomena was dependent on the CMS maize genotype and should be known before using CMS for coexistence purposes

    Relevance of β-Glucan Molecular Properties on Its Suitability as Health Promoting Bread Ingredient

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    The fate of β-glucan (BG) health promoting properties during food production is crucial, but not predictable yet. Therefore, high molar mass BG (hBG) and control BG (cBG) were extracted from two barley varieties, characterized and added to wheat breads at levels of 3% and 6%. Bread quality criteria, carbohydrate contents and BG content and structural properties were determined. Additionally, breads were subjected to an in vitro digestion. The BG content in the chyme, molar mass, molar ratio, viscosity and bile acid retention were determined. The hBG and the cBG decreased loaf volume and increased crumb hardness with increasing BG content. The reduction in BG content during bread making was similar for hBG and cBG, but the molar mass of cBG decreased to a greater extent. As a result, only 10% of cBG entering in vitro digestion were found in the chyme afterwards, while 40% of the ingested hBG were detected. Molar mass reduction was much more severe for cBG compared to hBG. The use of hBG showed higher viscosity and better bile acid retention, indicating cholesterol lowering properties, compared to similar or higher amounts of cBG. These results provide valuable knowledge on the criteria to select BG-rich raw materials for ideal health promoting properties

    Analyzing a Saturation Effect of Nitrogen Fertilization on Baking Volume and Grain Protein Concentration in Wheat

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    Some wheat cultivars show a linear relationship between grain protein concentration (GPC) and baking volume, but others display a saturation curve. Such a saturation curve could be general, but in some cultivars it might only appear at GPC > 17%. However, such GPC is mostly not achieved in the field. Pot experiments with high nitrogen application reliably result in GPC > 17%. In a pot experiment with a high (N1) and an excessive N level (N2) and four cultivars (Akteur, Arnold, Discus and Hystar), the change in grain protein composition and the relationship between different protein fractions and baking volume at GPC > 17% was investigated. GPC ranged from 17 to 24% and mean nitrogen content per grain from 1.2 to 1.8 mg. The N2 treatment increased GPC and mean nitrogen content per grain in the Akteur and Discus cultivar, but not in Arnold and Hystar. N2 increased concentration of gliadin by 10 to 34% and glutenin macropolymer (GMP) in all cultivars by 12 to 73%. Glutenin concentration was increased by N2 in Akteur and Discus (19 to 36%), but was decreased by N2 in the Arnold and Hystar cultivar. Baking volume was moderately increased by N2 in all cultivars by 6 to 9% and correlated significantly with most glutenin fractions in the Akteur and Discus cultivar, with GMP in Arnold and with HMW-GS to LMW-GS ratio in Hystar. Thus, specific effects on grain protein by N2 were responsible for the increased baking volume in each cultivar. However, as gliadin and its sub-fractions hardly correlated with baking volume, a positive effect of increasing gliadin proteins on baking quality was not obvious

    Pollen-mediated intraspecific gene flow from herbicide resistant oilseed rape (Brassica napus L.)

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    Abstract The cultivation of genetically modified (GM) herbicide resistant oilseed rape (Brassica napus) has increased over the past few years. The transfer of herbicide resistance genes via pollen (gene flow) from GM crops to non-GM crops is of relevance for the realisation of co-existence of different agricultural cultivation forms as well as for weed management. Therefore the likelihood of pollen-mediated gene flow has been investigated in numerous studies. Despite the difficulty to compare different experiments with varying levels of outcrossing, we performed a literature search for worldwide studies on cross-fertilisation in fully fertile oilseed rape. The occurrence and frequency of pollenmediated intraspecific gene flow (outcrossing rate) can vary according to cultivar, experimental design, local topography and environmental conditions. The outcrossing rate from one field to another depends also on the size and arrangement of donor and recipient populations and on the ratio between donor and recipient plot size. The outcrossing levels specified in the presented studies are derived mostly from experiments where the recipient field is either surrounding the donor field (continuous design) or is located as a patch at different distances from the donor field (discontinuous design). Reports of gene flow in Brassica napus generally show that the amount of cross-fertilisation decreases as the distance from the pollen source increases. The evidence given in various studies reveals that the bulk of GM crossfertilisation occurs within the first 10 m of the recipient field. The removal of the first 10 m of a nontransgenic field facing a GM crop might therefore be more efficient for reducing the total level of crossfertilisation in a recipient sink population than to recommend separation distances. Future experiments should investigate cross-fertilisation with multiple adjacent donor fields at the landscape level under different spatial distributions of rapeseed cultivars and different cropping systems. The level of crossfertilisation occurring over the whole field is mainly important for co-existence and has not been investigated in agricultural scale experiments until now. Potential problems with herbicide resistant oilseed rape volunteers arising from intraspecific gene flow can be largely solved by the choice of suitable cultivars and herbicides as well as by soil management

    Biological Confinement Strategies for Seed- and Pollen-Mediated Gene Flow of GM Canola (Brassica napus L.)

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    Canola (Brassica napus) varieties containing inherent restrictions on gene flow may address problems of seed- and pollen-mediated gene flow. The aim of this study was to explore the effectiveness of 1) low-dormancy varieties in avoiding GM soil seedbanks and volunteers, and 2) cleistogamous (clg) genotypes to avoid outcrossing. GM and non-GM varieties with altered seed ingredients had a wide dormancy range that turned out to be genetically determined. Quantitative trait locus (QTL) mapping identified four QTLs, which together explained 35% of the phenotypic variance. The fiber content of the seeds appeared to additionally affect seed dormancy. A qualitative polymerase chain reaction (PCR) assay was developed for clg canola by cloning and sequencing of clg1-specific DNA fragments. Detection of characteristic bands in 0.1% clg spiked samples illustrated the sensitivity of this method. The inherent traits of low dormancy and cleistogamy may be feasible tools to minimize gene flow and may be considered for coexistence of GM and non-GM canola
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