Das Projekt "Potential for transgene flow from wheat to its wild relatives Aegilops sp." wird vom Umweltbundesamt gefördert und von Universite de Neuchatel, Institut de Biologie durchgeführt. Transgenes inserted into crop plants could migrate into the genetic material of closely related wild types and cause undesirable effects - such as the development of resistance to herbicides. Background Goatgrasses (Aegilops) are genetically closely related to wheat and are often found in wheat fields, where they can be very aggressive weeds. If genetically modified wheat - for example a variety resistant to a certain herbicide - was brought onto the market on a large scale, there would be a danger of the modified genes migrating by means of wheat pollen into the genetic material (genome) of goatgrasses, making these weeds resistant to herbicides too. This risk has been demonstrated on many occasions. However, little is known about the actual probability of this gene migration occurring. Objectives The project aims to quantify to which extent the genes of genetically unmodified wheat have already mingled naturally with the genome of goatgrasses growing in the vicinity. The project also aims to assess the extent to which modified genes from transgenic wheat could spread into other, related wild types if they were to cross. Methods Various goat grasses from the Mediterranean region and North America will be investigated using genetic markers to establish how many genes have already migrated from unmodified wheat into the genome of these grasses through foreign pollination. The way these migrated genes are passed on to other related wild species will be investigated by cross-breeding various goatgrasses under both natural and experimental conditions. Significance The frequency with which wheat genes are transferred to closely related wild types and an understanding of the mechanisms by which the transferred genes spread among the wild types are important in assessing the risk associated with the development of marketable transgenic wheat varieties. In addition, the goatgrasses that will be studied are currently native predominantly around the Mediterranean and in North America but are likely to become more common in our country in the future, not least because of their migratory potential and the effects of global warming.
Das Projekt "Genfluss in ausgewaehlten Nutzpflanzen der Schweiz und verwandten Unkraeutern, Risikoeinschaetzung fuer den Feldanbau von genetisch veraenderten Pflanzen in der Schweiz - Phase 2" wird vom Umweltbundesamt gefördert und von Universite de Neuchatel, Institut de Botanique durchgeführt. Aim: Evaluation of gene flow from crops to related weeds under regular agricultural conditions. Means: 1) bibliographical database, 2) field work: collection of wild relatives in zones of contact; screening for hybrids by the methods of biometry and genetics/ elaboration of distribution maps and of risk indices (Dpdf codes) as a synthesis of all the gathered data. Evaluation of risk of gene flow between crops and wild relatives by sexual reproduction is carried out in a first step by bibliographical work and herbarium examination. Then, spontaneous occurrence of the crop and the wild relatives is censused on test areas. Populations of the wild species close to the cultivated field are sampled. Depending on the species, the plants themselves or their progeny are are analysed in order to detect spontaneous hybrids or introgressive individuals. Moreover, artificial crosses and natural hybridisations are carried out. The synthesis of the results is expressed by risk indices (Dpdf) codes, which translate hybridisation rate with the local flora, the risk of escape of diaspores in the wild and the distribution frequency of wild relatives.^Moyen: 1) base de donnees bibliographiques, 2) travail de terrain: collecte de plantes sauvages proches dans des zones de contacts, recherches d'hybrides par des approches en biometrie et des analyses genetiques/ elaboration de cartes de distribution et d'indices de risques (codes Dpdf) qui synthetisent l'ensemble des donnees. (FRA)
Das Projekt "Genetic and ecological consequences of introgression of transgenic wheat in a wild relative, Aegilops cylindrica: an open field experiment" wird vom Umweltbundesamt gefördert und von Universite de Neuchatel, Institut de Botanique durchgeführt. 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.
Das Projekt "Shedding light on biological diversity: facilitators and constraints of adaption to anthropogenic environmental changes" wird vom Umweltbundesamt gefördert und von Eawag - Das Wasserforschungsinstitut des ETH-Bereichs durchgeführt. Natural populations are increasingly exposed to extreme environmental changes as a result of human activities. These changes threaten the existence of populations and cause strong natural selection at short time-scales. In the long term, the persistence of populations is determined by their capacity to respond to this selection via genetic adaptation. It is therefore crucial to understand how evolutionary processes influence the ability of populations to cope with the ongoing environmental changes. This project focuses on studying two major factors that influence the ability of populations to adapt to rapid environmental change: gene flow (movement of genes resulting from dispersal of individuals) and maternal effects (the effects of a mother's traits that, in addition to offspring's own genes, affect offspring performance), both of which have the potential to either impede or speed up adaptation. On this vein, the proposed research focuses in particular on understanding how gene flow and maternal effects affect the ability of populations to adapt to environmental changes. The main part of the research will be conducted on Swedish populations of the moor frog (Rana arvalis) that inhabit areas affected to different extents by human-induced acidification. The main questions to be targeted are i) to what extent is the level of local adaptation to acidification explained by variation in the extent of gene flow or variation in the strength of selection among populations, ii) how wide-spread are maternal effects as adaptations and iii) how is maternally determined local adaptation maintained in the face of gene flow? Because experimental manipulations are not possible in these natural populations, related questions will in parallel be addressed in a pilot study on laboratory populations of Daphnia. Here the main questions to be targeted are i) under which conditions does gene flow have positive vs. negative effects on adaptation to novel environments and ii) how do maternal effects influence the ability to respond genetically to rapid environmental changes? Different complementary approaches will be used in the different subprojects to allow rigorous inferences and predictions. The main methods to be used include large-scale geographic sampling (for environmental, molecular genetic, and phenotypic variation) and mark-recapture studies in nature, molecular and quantitative genetic analyses in the laboratory, and fitness assays in semi-natural and laboratory conditions. The results from this research will illustrate to what extent gene flow and maternal effects influence variation in the phenotypes that we see in nature, and how they can affect the ability of organisms to adapt to novel environments. Ultimately this research aims at understanding the short-term ecological and evolutionary processes that create, maintain and change biological diversity, and will be of broad significance for evolutionary biology as well as conservation biology.