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Barley dwarfs acting big in agronomy. Identification of genes and characterization of proteins involved in dwarfism, lodging resistance and crop yield

Barley (Hordeum vulgare) is an important cereal grain which serves as major animal fodder crop as well as basis for malt beverages or staple food. Currently barley is ranked fourth in terms of quantity of cereal crops produced worldwide. In times of a constantly growing world population in conjunction with an unforeseeable climate change and groundwater depletion, the accumulation of knowledge concerning cereal growth and rate of yield gain is important. The Nordic Genetic Resource Center holds a major collection of barley mutants produced by irradiation or chemical treatment. One phenotypic group of barley varieties are dwarf mutants (erectoides, brachytic, semidwarf, uzu). They are characterized by a compact spike and high rate of yield while the straw is short and stiff, enhancing the lodging resistance of the plant. Obviously they are of applied interest, but they are also of scientific interest as virtually nothing is known about the genes behind the development of plant dwarfism. The aim of this project is to identify and isolate the genes carrying the mutations by using state of the art techniques for gene cloning at the Carlsberg Laboratory. The identified genes will be connected with the mutant phenotype to reveal the gene function in general. One or two genes will be overexpressed and the resulting recombinant proteins will be biochemically and structurally characterized. The insights how the mutation effects the protein will display the protein function in particular. Identified genes and their mutant alleles will be tested in the barley breeding program of the Carlsberg brewery.

Sicherung der genetischen Vielfalt von für die Unterlagenzüchtung relevanten Wildformen der Gattung Vitis

Eine hohe Resistenz gegen Bodenpathogene, gute Standortanpassung und Veredlungsaffinität sind die entscheidenden Merkmale von Unterlagen. Bei der Pathogenresistenz ist bei Reben die Widerstandsfähigkeit gegen die Reblaus Daktulosphaira vitifoiae essentiell, da die europäische Kulturrebe Vitis vinifera L über keinerlei Resistenzen verfügt und nur an wenigen Standorten ein wurzelechter Anbau möglich ist. Amerikanische Wildformen mit solchen Reblausresistenzen sind daher in der Unterlagenzüchtung von großer Bedeutung. Die langfristige Sicherung solcher Genotypen ist daher eine Voraussetzung für spätere Züchtungsarbeiten zur Erstellung neuer besserer Unterlagen. Daneben spielt auch die Standortanpassung eine wichtige Rolle. Vitis berlandieri ist hier am wichtigsten, da sie als einzige Art über eine hohe Kalkverträglichkeit verfügt und die Mehrheit der deutschen und europäischen Weinbaustandorte durch hohe Kalkgehalte im Boden charakterisiert sind. Kalkempfindliche Arten leiden unter Kalkchlorose mit stark vermindertem Wuchs. Aufgrund begrenzter Verfügbarkeit wurden jedoch nur wenige Pflanzen der Art in der Unterlagenzüchtung verwendet und damit nur ein Teil des Potentials der Art genutzt. In einem gemeinsamen Projekt mit dem United States Department for Agriculture wurden daher im September 2005 im ursprünglichen Verbreitungsgebiet der Art in Zentraltexas Samen von Wildformen gesammelt und die Hälfte davon in Geisenheim zur Keimung gebracht und ausgepflanzt. Derzeit werden mehr als 5000 Pflanzen in der in vivo Erhaltung. In den kommenden Jahren werden diese hinsichtlich ihrer relevanten Eigenschaften phänotypisch charakterisiert und in einem späteren Stadium auch genotypisiert, um für weitere Kreuzungs- und Selektionsarbeiten nutzbares material zu identifizieren.

Simulated field environment with combined salt and drought stresses as a platform for phenotyping plant tolerance to salinity

Salinity occurs often simultaneously with drought stress. Therefore, breeding for tolerance to combined both stresses can contribute significantly to crop yield. However, classical selection in salinity has generally been unsuccessful, partly due to high variability of salt stress resulting from the different salinity and drought status. Unfortunately, the use of unrealistic stress protocols for mimicking salinity and drought stress is the norm rather than the exception in biotechnological studies. Therefore, the great challenge is to gain knowledge required to develop plants with enhanced tolerance to field conditions. Our overall hypothesis is that a realistic stress protocol simulating a field environment with combined salt and drought stress as a platform for precision phenotyping of plant tolerance to salinity may solve this problem. This study will demonstrate that highly managed stress environments can be created and key traits of plants can be characterised by using advanced non-destructive sensors that are able to identify relevant traits of plants.

Züchtung von Rebunterlagen mit hoher Reblausfestigkeit und Anpassung an Trockenheit und Kalk-Chlorose

Eine hohe Resistenz gegen Bodenpathogene, gute Standortanpassung und Veredlungsaffinität sind die entscheidenden Merkmale von Unterlagen. Bei der Pathogenresistenz ist bei Reben die Widerstandsfähigkeit gegen die Reblaus Daktulosphaira vitifoiae essentiell, da die europäische Kulturrebe Vitis vinifera L über keinerlei Resistenzen verfügt und nur an wenigen Standorten ein wurzelechter Anbau möglich ist. Klimaveränderungen erfordern neue Unterlagen mit hoher Reblausfestigkeit und besserer Standortanpassung. Aufgrund der derzeitigen Szenarien werden sowohl Trockenresistenz als auch Toleranz gegen hohe Kalkgehalte insbesondere in Verbindung mit hohem Bodenwassergehalte zukünftig von Bedeutung sein. Hierfür werden entsprechende Kreuzungen vorgenommen, die Sämlinge aufgezogen, auf ihre Reblausfestigkeit getestet und anschießend Prüfungen der Wurzelungs- und Veredlungsfähigkeit vorgenommen. Anschließend wird die Witterungs- und Bodenanpassung der Zuchtstämme insbesondere auf Trocken- und Kalkstandorten untersucht. Ziel ist die Entwicklung verschiedener Unteralgen, die eine vollständige Reblausresistenz mit hohen Trockenheits- und/oder Kalktoleranz kombinieren.

Cassava for food security and sustainability in Colombia: Biotechnological application of mycorrhizal fungi

The Eastern Plains region of Colombia is a large tract of tropical savannah covering approximately 17Prozent of the Colombian land mass. It is an agriculturally poor region where current agricultural practices of cattle ranching have rapidly lead to poor soil fertility and low productivity. In Colombia, agriculture represents a very important part of the economy. In an attempt to economically stabilize the region the government has developed a regional plan for the Eastern Plains. This includes converting pasture land into cropping systems that provide food security for the growing Colombian population and reducing poverty.Cassava is the key crop in the regional plan for economic development and stability. However, cassava is a plant that is almost completely dependent on a symbiosis with arbuscular mycorrhizal fungi (AMF) to efficiently obtain nutrients and grow. AMF have already been shown to greatly enhance cassava yields in the field, even when added to soil that already contains AMF. They also allow farmers to reduce fertilizer inputs and use much cheaper sources of phosphate. However, to realistically use AMF to increase cassava yields and make cassava cropping more profitable, it is necessary to inoculate with native AMF in a sterile based carrier, with low transport costs. This project seeks to isolate native AMF from soils in the eastern plains and from the roots of cassava in native undisturbed populations, screen them for effectiveness in increasing cassava yields and then put some of the most effective ones into a clean sterile culture system on artificial media for mass production. These AMF isolates will be used as inocula in field trials. Because cassava is so mycorrhiza-dependent, we also propose to screen the genetic diversity of cassava for mycorrhizal responsiveness. The Swiss group will use their expertise in molecular genetics of AMF to develop a molecular marker system for quality control of AMF inoculum in cassava roots and perform a pilot AMF breeding approach to cross AMF and obtain genetically novel AMF for use in the field. The Swiss partner will train the Colombian group in these technologies. The results of the project will be disseminated within the framework of the socio-economic plan for the region developed by the National University of Colombia's Institute for Studies in Orinoquia. Researchers in that institute will use the results of this project to make economic projections of the impact of the results on small farms and cooperatives in the Eastern Plains and at the whole regional level. They will then accordingly disseminate the information to agronomists, farmers and land-owners in the region.

Mechanisms of oxidative stress tolerance in rice and their application in the molecular breeding of genotypes adapted to stress environments

Abiotic environmental stresses are among the major factors limiting agricultural productivity in many developing countries. A common feature of various environmental stresses is the excessive accumulation of reactive oxygen species (ROS) in the leaf tissue leading to 'oxidative stress' and in turn visible leaf lesions, reduced growth, and in severe cases plant death. This project aims at identifying molecular mechanisms associated with oxidative stress tolerance in rice (Oryza sativa L.) under three different environmental conditions: (i) high tropospheric ozone concentration, (ii) zinc deficiency, and (iii) iron toxicity. This is achieved by dissecting naturally occurring genotypic variability in oxidative stress tolerance into distinct quantitative trait loci (QTL). Physiological mechanisms and genes underlying such tolerance QTL are identified by adopting an interdisciplinary approach including biochemical characterization of the antioxidant systems, transcriptome profiling, and experiments with gene knock-out mutants for candidate genes. Theoretical understanding of stress tolerance mechanisms obtained from laboratory experiments would be validated in field experiments together with international research institutions and partners in developing countries. At a later stage, the project strives to adopt emerging techniques in gene discovery such as single nucleotide polymorphism (SNP) based association mapping, and apply lessons learned from studying the 'model cereal crop' rice to other species such as barley (Hordeum vulgare L.). The project is expected to contribute to world-wide efforts in adapting crop production to stress environments by specifically advancing the understanding of oxidative stress tolerance.

Genetic and ecological consequences of introgression of transgenic wheat in a wild relative, Aegilops cylindrica: an open field experiment

Establishment of modified genes If genes from genetically modified plants were to be passed on to their wild relatives, there could be serious ecological consequences, particularly if these genes were to become established in the genomes of wild plants. So far, little is known about these processes. Background One possible risk associated with genetically modified crop plants is the propagation of their genes through cross-breeding with closely related species. Scientists are seeking to assess whether resistance could be transferred from crop plants to weeds in this way and subsequently propagated in the weeds. If this was the case, these weeds would also become resistant to diseases or herbicides, an undesirable side effect. Objectives Hybrids of transgenic wheat and a close relative, jointed goatgrass (Aegilops cylindrica), will be grown under greenhouse conditions to generate information on the propagation of modified genes and whether they can become established in the genome of a wild species over several generations. The ecological consequences of this type of gene transfer will be investigated as part of the field trial with transgenic wheat (cf. Keller project I). Methods A first generation of transgenic wheat and jointed goatgrass hybrids will be bred in a greenhouse trial. Subsequent generations will be studied to see how the transgenic sequences from the wheat are passed on in the hybrids and how active they are. In addition, the ecological consequences will be assessed in a field trial. Significance There is already considerable information about the risk of cross-breeding between transgenic crop plants and their wild relatives, but little is known about the ecological consequences. The project closes this gap by investigating how the modified genes from transgenic wheat can be inherited in cross-breeding with goatgrass and whether the resulting plants have new ecological traits such as undesirable resistance.

Schwerpunktprogramm (SPP) 1530: Flowering time control: from natural variation to crop improvement, Is the immune system required to adapt to flowering time change?

For effective crop improvement, breeders must be able to select on relevant phenotypic traits without compromising yield. This project proposes to investigate the evolutionary consequences of flowering time modifications on a second trait of major importance for plant breeding: immunity. This will have implications both for understanding cross-talks between flowering time and defense network and for developing efficient breeding strategies. There is clear evidence that plant maturity influences levels and effectiveness of defense. Theoretical models actually predict that changes in life-history can modulate the balance between costs and benefits of immunity. Simultaneously, actors of the immune system have often been observed to alter flowering time. Two alternative and possibly complementary hypotheses can explain this link: genetic constraints due to the pleiotropic action of players in either systems, or co-evolution, if flowering-time changes modulate the cost-benefit balance of immunity. We will conduct field assays in Arabidopsis thaliana, using constructed lines as well as recombinant inbred lines and natural accessions, to differentiate the action of the two explanatory hypotheses. Using transcriptome analyses, we will identify defense genes associating with flowering time modification (f-t-a defense genes). We will quantify their expression along the assay and test whether it varies with both flowering time and fitness. We will further test whether flowering time and immunity interact to determine yield in tomato and potato.

Schwerpunktprogramm (SPP) 1530: Flowering time control: from natural variation to crop improvement, Analysis of genetic variation for flowering time in wild barley grown under different environmental conditions

The time of flowering is crucial for a plant's adaptation to a given environment and has a major impact on grain yield in crop species. A large number of flowering time genes have been identified in A. thaliana, and many of them are structurally conserved across species including cereals. However, the majority of these orthologs have not been functionally characterized in barley or wheat so far. Here, we propose to conduct the first comprehensive survey on variation in flowering time candidate genes and flowering time behavior under different environmental conditions in wild barley, Hordeum spontaneum Thell. We aim at identifying novel associations between candidate genes and flowering time, and to advance the functional characterization of flowering time genes in barley. To this end we will I) characterize genetic variation at 16 candidate genes in a unique collection of 480 diverse barley lines established by the applicant, II) associate genetic variation with flowering behavior under different field and controlled conditions, and III) analyze gene expression and characterize genetic diversity in putative regulatory regions of candidate genes. The characterization of natural genetic variation at flowering time candidate genes will make an important contribution to understanding developmental genetic processes underlying adaptation and thus grain yield in barley and other grasses and increase the pool of alleles available for breeding.

Modellierung geeigneter Wiederansiedelungshabitate für die Flussperlmuschel (Margaritifera margaritifera) -Methodenentwicklung (FLUP-Habitat)

Die Flussperlmuschel (Margaritifera margaritifera) ist als vom Aussterben bedrohte Art einzustufen. Die Nachzucht der Muschel gelang in den letzten Jahren mittels einer eigens errichteten Nachzuchtstation jedoch durchaus sehr erfolgreich. Um für die Wiederansiedelung der Flussperlmuschel in Fließgewässern zu gewährleisten gilt es vorab geeignete Lebensraumbedingungen zu finden. Dabei ist die Habitatmodellierung als geeignetes Instrument für eine Bewertung bzw. eine Vorauswahl anzusehen. Diese Modellierung beruht auf Eingangsparametern, die in intakten Flussperlmuschelgewässern erhoben werden müssen. Solche intakten Gewässer mit reproduktiven Flussperlmuschelpopulationen existieren aktuell nur noch in Nordeuropa (z. B. Schweden, Finnland, Norwegen) und in einem deutschen Heidebach, der Lutter, in der ein umfangreiches, das gesamte Einzugsgebiet umfassendes Sanierungs- und Wiederansiedelungsprojekt sehr erfolgreich umgesetzt wurde. Ziel des Projektes ist es, in verschiedenen österreichischen Gewässern jene (Lebensraum-)Parameter zu erfassen, welche von der Flussperlmuschel genutzt bzw. auch nicht genutzt werden, um funktionale Zusammenhänge für ein zukünftiges Management zu erkennen, bzw. auch jene Nutzungskurven abzuleiten, die für mögliche hydraulische Modellanwendungen zur Habitatevaluierung benötigt werden. Um dieses Ziel zu Erreichen wird eine Charakterisierung der Gewässermorphologie mittels tachymetrischer Vermessung von genutzten und nicht genutzten Gewässerprofilen durchgeführt als Grundlage für die eindimensionale numerische Modellierung (HEC-RAS). Weiters werden Kornverteilungskurven mittels volumetrischer Beprobung aus Deck- und Unterschicht erstellt mit einer Bestimmung der Feinsedimentanteile (kleiner als 0,063 mm, kleiner als 0,125 mm, kleiner als 0,250 mm) durchgeführt.

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