Cherry leaf roll virus (CLRV) is a plant pathogen of economic and ecologic importance. It is globally distributed in a wide range of forest, fruit, and ornamental trees and shrubs. In several areas of cherry and walnut production CLRV causes severe losses in yield and quality. With current reference to the rapid dissemination and strong symptom expression in Finnish birches and the Germany-wide distribution of CLRV in birches and elderberry, we continuously investigate and gradually reveal CLRV transmission pathways as by pollen, seeds or water. However, modes and interactions responsible for the wide intergeneric host transmission as well as for the exceptional CLRV epidemic in Fennoscandia still remain unknown. In this project systematic studies shall investigate biological vectors as a causal agent to finally derive control mechanisms and strategies to avoid new epidemics in different hosts and geographic regions. Detailed monitoring of the invertebrate fauna of birch stands/forests and elderberry plantations in Germany and Finland shall reveal potential vectors to subsequently study them in detail by approved virus detection methods and transmission experiments. Molecular analyses of the CLRV coat protein shall prove its role as a viral determinant for a virus/vector interaction. Consequently, this project essentially will contribute important answers on the CLRV epidemiology, and this will be a key element within the first network of research on plant viral pathogens in forest trees.
Cydia pomonella granulovirus (CpGV, Baculoviridae) is one of the most important agents for the control of codling moth (CM, Cydia pomonella, L.) in both biological and integrated pest management. The rapid emergence of resistance against CpGV-M, which was observed in about 40 European CM field populations from 2003 on, could be traced back to a single, dominant, sex-linked gene. Since then, resistance management has been based on mixtures of new CpGV isolates (CpGV-I12, -S), which are able to overcome this resistance. Recently, resistance even to these novel isolates was observed in CM field populations. This resistance does not follow the described dominant, sex-linked inheritance trait. At the same time, another isolate CpGV-V15 was identified showing high virulence against these resistant populations. To elucidate this novel resistance mechanism and to identify the resistance gene(s) involved, we propose a comprehensive analysis of this resistance on the cellular and genomic level of codling moth. Because of the lack of previous knowledge of the molecular mechanisms of virus resistance in insects, several different and complementary approaches will be pursued. This study will not only give an in-depth insight into the genetic possibilities for development of baculovirus resistance in CM field populations and how the virus overcomes it, but can also serve as an important model for other baculovirus-host interaction systems.
The goal of this project is to capture and analyse fluctuations of the fresh water in the western Nordic Seas and to understand the related processes. The East Greenland Current in the Nordic Seas constitutes an important conduit for fresh water exiting the Arctic Ocean towards the North Atlantic. The Arctic Ocean receives huge amounts of fresh water by continental runoff and by import from the Pacific Ocean. Within the Arctic Ocean fresh water is concentrated at the surface through sea ice formation. The East Greenland Current carries this fresh water in variable fractions as sea ice and in liquid form; part of it enters the central Nordic Seas, via branching of the current and through eddies. It controls the intensity of deep water formation and dilutes the water masses which result from convection. The last decades showed significant changes of the fresh water yield and distribution in the Nordic Seas and such anomalies were found to circulate through the North Atlantic. In this project the fresh water inventory, its spatial distribution and its pathways between the East Greenland Current and the interior Greenland and Icelandic seas shall be captured by autonomous glider missions. The new measurements and existing data will, in combination with the modeling work of the research group, serve as basis for understanding the causes of the fresh water variability and their consequences for the North Atlantic circulation and deep water formation.
Traditional Indonesian homegardens harbour often high crop diversity, which appears to be an important basis for a sustainable food-first strategy. Crop pollination by insects is a key ecosystem service but threatened by agricultural intensification and land conversion. Gaps in knowledge of actual benefits from pollination services limit effective management planning. Using an integrative and agronomic framework for the assessment of functional pollination services, we will conduct ecological experiments and surveys in Central Sulawesi, Indonesia. We propose to study pollination services and net revenues of the locally important crop species cucumber, carrot, and eggplant in traditional homegardens in a forest distance gradient, which is hypothesized to affect bee community structure and diversity. We will assess pollination services and interactions with environmental variables limiting fruit maturation, based on pollination experiments in a split-plot design of the following factors: drought, nutrient deficiency, weed pressure, and herbivory. The overall goal of this project is the development of 'biodiversity-friendly' land-use management, balancing human and ecological needs for local smallholders.
Der Ozean im Westpazifik ist mit Temperaturen von ganzjährig 30°C der wärmste Ozean der Welt. Im tropischen Westpazifik ist die Lufttemperatur der Grenzschicht weltweit am höchsten und die Ozonkonzentration am niedrigsten. Aufgrund der allgemeinen Advektion der Luftmassen in der unteren und mittleren Troposphäre aus dem Osten durch die Walker-Zirkulation über den Pazifik befindet sich die Luft über dem tropischen Westpazifik für längere Zeit in einer sauberen, warmen und feuchten Umgebung. Der Abbau von reaktiven Sauerstoff- und Ozonvorläufern wie NOx findet daher länger als anderswo in den Tropen, was zu sehr niedrigen Ozonkonzentrationen führte. Dies erhöht die Lebensdauer von kurzlebigen biogenen und anthropogenen Spurengasen. Darüber hinaus begünstigen hohe Meeresoberflächentemperaturen eine starke Konvektion im tropischen Westpazifik, was zu niedrigen Ozonmischungsverhältnissen in den konvektiven Ausflussgebieten in der oberen Troposphäre führen kann. Der Warmpool im Westpazifik ist auch eine wichtige Quellregion für stratosphärische Luft. Daher fallen die Region, in der die Lebensdauer kurzlebiger Spurengase erhöht ist, und die Quellregion der stratosphärischen Luft zusammen. Somit bestimmt die Zusammensetzung der troposphärischen Atmosphäre in dieser Region in hohem Maße auch die globale stratosphärische Zusammensetzung.Ozon ist aufgrund von Rückkopplungsprozessen zwischen Temperatur, Dynamik und Ozon ein wichtiges Spurengas in der Klimaforschung. Da der Warmpool im Westpazifik die Hauptquellenregion für stratosphärische Luft ist, ist die Kenntnis von Ozon und anderen kurzlebigen Spurengasen auch wichtig, um den Transport von Spurengasen in die Stratosphäre zu verstehen.Ziel unseres Projektes ist die Messung des Tagesgangs von Ozon und anderen Spurengasen mit Hilfe der hochauflösenden solaren Absorptions-FTIR-Spektroskopie. Die Messungen liefern die Gesamtsäulendichten von bis zu 20 Spurengasen. Für einige Spurengase erlaubt die Analyse der Spektrallinienform die Ableitung der Konzentrationsprofile in bis zu etwa vier atmosphärischen Höhenschichten. Ergänzt werden die Beobachtungen durch Ozonballonsondierungen, kontinuierliche Messungen der UV-Strahlung, und Modellrechnungen mit einem Chemie-Transport-Modell. Die Messungen sind für den Zeitraum August bis Oktober 2022 geplant, die Auswertung und Interpretation von November 2022 bis Januar 2023.
In the Earth, the dynamo action is strongly linked to core freezing. There is a solid inner core, the growth of which provides a buoyancy flux that drives the dynamo. The buoyancy in this case derives from a difference in composition between the solid inner core and the fluid outer core. In planetary bodies smaller than the Earth, however, this core differentiation process may differ - Fe may precipitate at the core-mantle boundary (CMB) rather than in the center and may fall as iron snow and initially remelt with greater depth. A chemical stable sedimentation zone develops that comprises with time the entire core - at that time a solid inner core starts to grow. The dynamics of this system is not well understood and also whether it can generate a magnetic field or not. The Jovian moon Ganymede, which shows a present-day magnetic dipole field, is a candidate for which such a scenario has been suggested. We plan to study this Fe-snow regime with both a numerical and experimental approach. In the numerical study, we use a 2D/3D thermo-chemical convection model that considers crystallization and sinking of iron crystals together with the dynamics of the liquid core phase (for the 3D case the influence of the rotation of the Fe snow process is further studied).The numerical calculations will be complemented by two series of experiments: (1) investigations in metal alloys by means of X-ray radioscopy, and (2) measurements in transparent analogues by optical techniques. The experiments will examine typical features of the iron snow regime. On the one hand they will serve as a tool to validate the numerical approach and on the other hand they will yield important insight into sub-processes of the iron snow regime, which cannot be accessed within the numerical approach due to their complexity.
Im letzten Jahrzehnt war der grönländische Eisschild mehreren Extremereignissen ausgesetzt, mit teils unerwartet starken Auswirkungen auf die Oberflächenmassebilanz und den Eisfluss, insbesondere in den Jahren 2010, 2012 und 2015. Einige dieser Schmelzereignisse prägten sich eher lokal aus (wie in 2015), während andere fast die gesamte Eisfläche bedeckten (wie in 2010).Mit fortschreitendem Klimawandel ist zu erwarten, dass extreme Schmelzereignisse häufiger auftreten und sich verstärken bzw. länger anhalten. Bisherige Projektionen des Eisverlustes von Grönland basieren jedoch typischerweise auf Szenarien, die nur allmähliche Veränderungen des Klimas berücksichtigen, z.B. in den Representative Concentration Pathways (RCPs), wie sie im letzten IPCC-Bericht genutzt wurden. In aktuellen Projektionen werden extreme Schmelzereignisse im Allgemeinen unterschätzt - und welche Konsequenzen dies für den zukünftigen Meeresspiegelanstieg hat, bleibt eine offene Forschungsfrage.Ziel des vorgeschlagenen Projektes ist es, die Auswirkungen extremer Schmelzereignisse auf die zukünftige Entwicklung des grönländischen Eisschildes zu untersuchen. Dabei werden die unmittelbaren und dauerhaften Auswirkungen auf die Oberflächenmassenbilanz und die Eisdynamik bestimmt und somit die Beiträge zum Meeresspiegelanstieg quantifiziert. In dem Forschungsprojekt planen wir zudem, kritische Schwellenwerte in der Häufigkeit, Intensität sowie Dauer von Extremereignissen zu identifizieren, die - sobald sie einmal überschritten sind - eine großräumige Änderung in der Eisdynamik auslösen könnten.Zu diesem Zweck werden wir die dynamische Reaktion des grönländischen Eisschilds in einer Reihe von Klimaszenarien untersuchen, in denen extreme Schmelzereignisse mit unterschiedlicher Wahrscheinlichkeit zu bestimmten Zeitpunkten auftreten, und die Dauer und Stärke prognostisch variiert werden. Um indirekte Effekte durch verstärktes submarines Schmelzen hierbei berücksichtigen zu können, werden wir das etablierte Parallel Ice Sheet Model (PISM) mit dem Linearen Plume-Modell (LPM) koppeln. Das LPM berechnet das turbulente submarine Schmelzen aufgrund von Veränderungen der Meerestemperatur und des subglazialen Ausflusses. Es ist numerisch sehr effizient, so dass das gekoppelte PISM-LPM Modell Ensemble-Läufe mit hoher Auflösung ermöglicht. Folglich kann eine breite Palette von Modellparametern und Klimaszenarien in Zukunftsprojektionen in Betracht gezogen werden.Mit dem interaktiv gekoppelten Modell PISM-LPM werden wir den Beitrag Grönlands zum Meeresspiegelanstieg im 21. Jahrhundert bestimmen, unter Berücksichtigung regionaler Veränderungen von Niederschlag, Oberflächen- und Meerestemperaturen, und insbesondere der Auswirkungen von Extremereignissen. Ein Hauptergebnis wird eine Risikokarte sein, die aufzeigt, in welchen kritischen Regionen Grönlands zukünftige extreme Schmelzereignisse den stärksten Eisverlust zur Folge hätten.
Flowering time (FTi) genes play a key role as regulators of complex gene expression networks, and the influence of these networks on other complex systems means that FTi gene expression triggers a cascade of regulatory effects with a broad global effect on plant development. Hence, allelic and expression differences in FTi genes can play a central role in phenotypic variation throughput the plant lifecycle. A prime example for this is found in Brassica napus, a phenotypically and genetically diverse species with enormous variation in vernalisation requirement and flowering traits. The species includes oilseed rape (canola), one of the most important oilseed crops worldwide. Previously we have identified QTL clusters related to plant development, seed yield and heterosis in winter oilseed rape that seem to be conserved in diverse genetic backgrounds. We suspect that these QTL are controlled by global regulatory genes that influence numerous traits at different developmental stages. Interestingly, many of the QTL clusters for yield and biomass heterosis appear to correspond to the positions of meta-QTL for FTi in spring-type and/or winter-type B. napus. Based on the hypothesis that diversity in FTi genes has a key influence on plant development and yield, the aim of this study is a detailed analysis of DNA sequence variation in regulatory FTi genes in B. napus, combined with an investigation of associations between FTi gene haplotypes, developmental traits, yield components and seed yield.
The energetic efficiency of C4 photosynthesis is strongly affected by bundle sheath leakiness, which is commonly assessed with the 'linear version' of the Farquhar model of 13C discrimination, and leaf gas exchange and 13C composition data. But, the linear Farquhar model is a simplification of the full mechanistic theory of ? in C4 plants, potentially generating errors in the estimation of leakiness. In particular, post-photosynthetic C isotope fractionation could cause large errors, but has not been studied in any detail. The present project aims to improve the understanding of the ecological and developmental/physiological factors controlling discrimination and leakiness of the perennial grass Cleistogenes squarrosa. C. squarrosa is the most important member of the C4 community which has spread significantly in the Mongolia grasslands in the last decades. It has an unusually high and variable discrimination, which suggests very high (and potentially highly variable) leakiness. Specifically, we will conduct the first systematic study of respiratory 13C fractionation in light and dark at leaf- and stand-scale in this C4 species, and assess its effect on discrimination and estimates of leakiness. These experiments are conducted in specialized 13CO2/12CO2 gas exchange mesocosms using ecologically relevant scenarios, testing specific hypotheses on effects of environmental drivers and plant and leaf developmental stage on discrimination and leakiness.
Chlorinated ethylenes are prevalent groundwater contaminants. Numerous studies have addressed the mechanism of their reductive dehalogenation during biodegradation and reaction with zero-valent iron. However, despite insight with purified enzymes and well-characterized chemical model systems, conclusive evidence has been missing that the same mechanisms do indeed prevail in real-world transformations. While dual kinetic isotope effect measurements can provide such lines of evidence, until now this approach has not been possible for chlorinated ethylenes because an adequate method for continuous flow compound specific chlorine isotope analysis has been missing. This study attempts to close this prevalent research gap by a combination of two complementary approaches. (1) A novel analytical method to measure isotope effects for carbon and chlorine. (2) A carefully chosen set of well-defined model reactants representing distinct dehalogenation mechanisms believed to be important in real-world systems. Isotope trends observed in biotic and abiotic environmental dehalogenation will be compared to these model reactions, and the respective mechanistic hypotheses will be confirmed or discarded. With this hypothesis-driven approach it is our goal to elucidate for the first timdehalogenation reactions.
| Organisation | Count |
|---|---|
| Bund | 460 |
| Europa | 22 |
| Land | 2 |
| Wirtschaft | 1 |
| Wissenschaft | 235 |
| Zivilgesellschaft | 3 |
| Type | Count |
|---|---|
| Förderprogramm | 460 |
| License | Count |
|---|---|
| Offen | 460 |
| Language | Count |
|---|---|
| Deutsch | 85 |
| Englisch | 447 |
| Resource type | Count |
|---|---|
| Keine | 371 |
| Webseite | 89 |
| Topic | Count |
|---|---|
| Boden | 406 |
| Lebewesen und Lebensräume | 454 |
| Luft | 355 |
| Mensch und Umwelt | 460 |
| Wasser | 358 |
| Weitere | 460 |