2,815 research outputs found
Screening of winter barley varieties (Hordeum vulgare) for resistance against loose smut (Ustilago nuda) and covered smut (Ustilago hordei) in Germany
Up to now organic farmers depend greatly on conventionally bred and produced varieties of barley. A turning point was set in 2004 by EU regulation No. 1452/2003 restricting the use of conventionally propagated seed and planting material for organic agriculture. Concerning smut fungi in barley, conventional seed producer's attention was rarely directed to plant resistance due to the possibility of chemical seed treatment (controlling the diseases completely). A main problem for organic seed producers is that organically produced seeds have to fulfil the same regular phytosanitary requirements like conventionally produced seeds. For the production of certified seeds not more than five ears infected with Ustilago hordei (Uh) and/or U. nuda (Un) are allowed on an area of 150 m² in Germany (RUTZ 1998). Though warm or hot water treatment can give excellent control of Un and Uh in organic farming (WINTER et al. 1996), the effect is not sufficient for seed production. Even biological control agents (for example Tillecur®) cannot reach the demands of the guidelines reliably. As an effective way to keep the restrictions remains the cultivation of resistant varieties. Aim of the presented study was to screen winter barley varieties for their degree of smut resistance in Germany. It started in 2000 (KLAUSE & SPIESS 2003) and is sponsored within the Federal Organic Farming Scheme since 2002
Strategic use of virulence pattern to develop genetic markers for resistance to common bunt (Tilletia caries) in wheat
When assesssing races of common bunt for virulens pattern within a region, it is important to take into account that collected spores may represent a diverse population of different virulence races.
When screening spores on a differential set of wheat lines with known resistance genes, a low infection rate on a resistant wheat variety does not necessarily demonstrate that virulence is absent in the spore collection, but could be a sign that virulence is present, but only present in a low frequency among the spores. If just a few spores within a spore sample are indeed virulent, they may infect some plants and from there multiply the virulence quite rapidly next years. Previous studies have shown that virulence against most resistance genes were present in Denmark after purifying races of common bunt (Tilletia caries) on resistant varieties. So far, only wheat differential varieties with Bt4, Bt6, Bt9, Bt11 and Bt12 cannot be infected with bunt races purified from Danish collections [1, and later own unpublished data]. Virulence against Bt4, Bt6 and Bt9 has been found in other European studies [2], and Bt11 may not be only one gene but a combination of at least two genes [3]. Therefore, Bt12 seems to be the only gene for which virulence have not been found in European population of common bunt. This leads to the conclusion that if resistance breeding shall safely control common bunt in wheat, we need not only one effective gene, but a combination of pyramided genes. Since it is very difficult to test if a resistant line has only one gene or more genes, the most effective tool to achieve this at present are genetic markers.
Using Genome Wide Association Studies (GWAS) to find QTLs and markers for the major resistance genes in wheat have so far led to only few commercial useful markers. Till now, only markers for Bt9 [6] and Bt10 are used in practice, but a marker for Bt12 [4] and Blizzard [7] have also been found. One of the problems in developing markers for bunt resistance have been that spores used in GWAS trials have been divers or unknown in virulence, and that phenotypic results not distinguishes between different resistance genes. Therefore, the most successful studies have used segregating populations of single crosses where the resistance gene is known on before hand [5].
In the LIVESEED project, we have the ambition to develop genetic markers on several different resistance genes at the same time. We will do so by testing segregating populations of several different crosses between varieties with 7 different resistance genes, and infect them with 7-11 different virulence races of common bunt able to distinguish between the resistance genes. A total of 300 varieties will be pheno- and genotyped. Using this experimental design, we attempt during 2018 and ‘19 to develop markers for Bt1, Bt2, Bt5, Bt7, Bt13, BtZ and Quebon-resistance, and hopefully also a couple of minor QTLs
Current use of Spatial Information Technology in Megacity Management
One objective of FIG Commission 3 focuses on promoting the use of Spatial Infrastructure Management (SIM)-tools at different administrative levels for decision makers and citizens to support the goals of participatory democracy. In this context FIG Commission 3 has set up the Working Group WG3.2 Spatial Data Infrastructures in Mega cities, which aims at identifying relevant spatial tools to support development and use of spatial data infrastructure (SDI) by city authorities in the world’s largest cities. The strategy of the work program emphasizes key problems of mega cities by reviewing SDI developments in existing mega cities, documenting case studies, including lessons learned about solutions for problems and should finally lead to a toolkit for use of best practises in SDI for managing mega cities. To complement the results of direct correspondence with administrations of mega cities one important part of this project concentrates on a background research of existing sources about overall use of SDI in mega cities.
The objective of this paper is to discuss the results of an internet search concerning the use of Spatial Information Technology in the world’s currently existing mega cities. The search starts from a nationwide view on the execution and the progression status of SDI’s in the home countries of mega cities and zooms in to the specific aspects of spatial data management in the metropolitan areas of special interest. As a result we come to the conclusion, that current SDI development in mega cities covers the whole range from first stage conceptual ideas up to an almost complete operational SDI availability
Sortenevaluierung hinsichtlich Flugbrand (Ustilago nuda) und Hartbrand (Ustilago hordei) zur Entwicklung einer Strategie für die Regulierung von saatgutübertragbaren Krankheiten bei der Erzeugung von Wintergerstensaatgut im Ökologischen Landbau
An den ökologisch bewirtschafteten Standorten Darzau/Neu Darchau und Dottenfelderhof/Bad Vilbel wurden 91 Sorten und Genbankmuster von Wintergerste unter natürlichen Infektionsbedingungen und nach Inokulation der Blüten auf Anfälligkeit gegenüber Flugbrand sowie 88 Wintergerstensorten der Beschreibenden Sortenliste 2002 und 2003 auf Anfälligkeit gegenüber Hartbrand getestet.
Gegenüber Flugbrand befallsfrei blieben die Handelssorten ASTRID und CARRERO sowie elf Genbankmuster. Acht weitere Wintergersten blieben nur unter natürlichen Infektionsbedingungen befallsfrei. Die beiden Sorten CORNELIA und SERAFINA wurden mit einem natürlichen Flugbrandbefall über 5 % als besonders anfällig ermittelt. Für die meisten flugbrandfrei gebliebenen Wintergersten kann aufgrund des einjährigen Ergebnisses noch keine gesicherte Aussage über deren Resistenz gemacht werden. Da sich für den Umgang mit Flugbrand derzeit keine Behandlungsalternativen abzeichnen, stellt sich die Züchtung auf Resistenz angesichts einiger bereits verbreiteter Resistenzen als der einzig gangbare Weg zu gesundem Saatgut im ökologischen Landbau dar.
Ohne Befall mit Hartbrand blieben die zweizeiligen Wintergersten KRETA, DUET und JOLANTE und die mehrzeiligen Wintergersten ALISSA, ELFE, USCHI und VERENA. Weitere 36 Sorten wiesen einen Hartbrandbefall unter 1% auf. Da Hartbrandsporen dem Saatgut nur von außen anhaften, eröffnet sich angesichts des hohen Anteils gering anfälliger Sorten im Falle eines Befalls die Perspektive der Kombination mit einem ökologischen Saatgutbehandlungsmittel.
Hinsichtlich der Inokulationstechnik beim Flugbrand hat sich die künstliche Infektion nach POEHLMAN mit 1 ml einer Flugbrandsporensuspension der Konzentration 1 g Sporen auf 1 Liter Wasser zur Injektion in die Blüten einer Ähre als optimal erwiesen. Für die Inokulation mit Hartbrand war die Sporenkonzentration von 1g Sporen pro kg Saatgut richtig. Zur sicheren Beurteilung und Unterscheidung der gegenüber Hartbrand gering anfälligen und resistenten Sorten muss die Gesamtfläche von 6m² pro Sorte als noch zu klein angesehen werden
An overnational cereal circuit for developing locally adapted organic seeds of wheat
On several locations in Germany and Switzerland, new and local varieties of winter wheat were compared to the variety "Bussard" in trial plots with 2-4 replications. Among other parameters, baking quality and gluten content were analised and discussed
Laser Beam Polishing of Quartz Glass Surfaces
The laser beam is a small, flexible and fast polishing tool. With laser radiation it is possible to finish many outlines or geometries on quartz glass surfaces in the shortest possible time. It's a fact that the temperature developing while polishing determines the reachable surface smoothing and, as a negative result, causes material tensions. To find out which parameters are important for the laser polishing process and the surface roughness respectively and to estimate material tensions, temperature simulations and extensive polishing experiments took place. During these experiments starting and machining parameters were changed and temperatures were measured contact-free
Advanced Analysis of Laser Beam Polishing of Quartz Glass Surfaces
The laser beam is a small, flexible and fast polishing tool. With laser radiation it is possible to finish many outlines or geometries on quartz glass surfaces in the shortest possible time. It’s a fact that the temperature developing while polishing determines the reachable surface smoothing and, as a negative result, causes material tensions. To find out which parameters are important for the laser polishing process and the surface roughness respectively and to estimate material tensions, temperature simulations and extensive polishing experiments took place. During these experiments starting and machining parameters were changed and temperatures were measured contact-free. The accuracy of thermal and mechanical simulation was improved in the case of advanced FE-analysis
Advanced Methods for Spatial Analysis of Bioaerosol Long-Range Transport Processes
Research on bioaerosol is still in its infancy. The dynamics and, therefore, the effects on atmospheric processes and the biosphere are often underestimated, or have not yet been sufficiently investigated. Atmospheric models such as FLEXPART and HYSPLIT enable researchers to simulate the transport of particles in the atmosphere and provide information on where air-parcels originate from. In the following, we present two methods for combining results of these models with spatial information, e.g., about vegetation. The first method shows how spatial CORINE land cover distribution can be analyzed within the boundaries of HYSPLIT trajectories. In a second method, FLEXPART simulations are used in combination with COSMO rain data and tree maps to generate maps that indicate the potential origin of bioaerosol for selected periods of time
Documentation of Medieval caves in southern Crimea (Ukraine) using hybrid data sources
The subject of this article is the geometric documentation of more than 500 caves cut into the soft rock of the plateau of Eski-Kermen, a medieval settlement on the highlands of the south-western Crimea. The types of caves and carved surface areas vary from very simple to extensive ones. A large number of traces and objects were recorded as basis for the understanding of the use of the caves, which were modified throughout the centuries until recent times. The aim of our sub-project is to develop a comprehensive system of effective geometric and archaeological documentation for further studies of cave settlements
Discrimination between S²⁻ and SO²⁻ Sites in Mixed Crystal Compounds Containing Co and Co/Mo Clusters by ⁵⁹Co-NMR Spectroscopy, and the Relevance for HDS Catalysis
In aqueous solutions of the mixed crystal compounds with formal composition K8[Co4-xMoxS4-y(SO)y(CN)12·nH2O (x = 0–2; y = 0–2) i) there are distinct CoS, Co(SO), and Co(SO)2 sites and ii) no hetero-metal clusters are present. These results, revealed by 59Co–NMR, could principally not be disclosed by single crystal X-ray structure analysis. The NMR data also suggest a stable dinuclear cobalt-sulphur cluster in solution. The relevance for HDS catalysis is discussed
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