10 research outputs found

    Populationsgenetische Differenzierung beim Eichenwickler (Tortrix viridana L.) und seiner Wirtspflanze (Quercus robur L.) anhand nukleärer Genmarker

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    In Western Europe pedunculate oak (Quercus robur L.) is the forest tree with the highest number of phytophagous insect species (Yela & Lawton 1997). One of these, the green oak leaf roller Tortrix viridana L. is an oligophagous herbivorous moth with a host range limited to the genus Quercus (Hunter 1990, Du Merle 1999). During outbreaks, T. viridana often leads to defoliation of oaks in spring. The abundance of T. viridana is subject to the population size fluctuations typical for herbivorous insects, where periods of small population sizes (latent periods) alternate with periods of high population sizes (outbreak) (e.g. Schütte 1957, Horstmann 1984). Apart from many experimental studies on population dynamics of the moth (e.g. Hunter 1990, Du Merle 1999, Ivashov & al. 2002) so far little attention has been paid to the genetic variation within the species as an important aspect of the genetics of this host-parasite interaction. Simchuk & al. (1999) found changes in the heterozygosity level of different isozyme loci during outbreaks in T. viridana and molecular markers for T. viridana have been developed for analyses of genetic variation within and among populations (Schroeder & Scholz 2005). But, investigations of genetic variation within and among populations of forest pest species are important to predict future pest outbreaks. So far the processes outbreaks based on are not entirely clarified, however it is known that migration plays a major role. Using molecular markers investigations of the genetic variation are possible and offer the opportunity to analyse distribution events. In this paper first results are presented concerning the genetic variation of the green oak leaf roller at three geographic scales: (1) among trees within a population, (2) among populations at a small spatial scale of about 150 km and (3) among populations at a broader geographic scale up to 3000 km. Furthermore results of the genetic variation of oaks at the small spatial scale are represented.Populationen des grünen Eichenwicklers (Tortrix viridana L., Lepidoptera: Tortricidae) und der Stieleiche (Quercus robur L., Fagaceae) wurden auf genetische Differenzierungen mit Hilfe von Kern-DNA-Markern untersucht. Insgesamt wurden 14 Eichenbestände in Nordrhein-Westfalen (NRW) und 7 weitere in verschiedenen Regionen Europas in die Untersuchung einbezogen. Weder für die Eiche noch für den Eichenwickler sind genetische Differenzierungen der Populationen auf einer kleinen geographischen Skala (etwa 150 km) nachweisbar, jedoch zeigen die Eichenpopulationen eine zunehmende genetische Distanz mit zunehmender geographischer Distanz. Für den Eichenwickler konnten innerhalb von Populationen in einem Radius von etwa 40 m Familienstrukturen ermittelt werden und auf einer kontinentalen Skala lassen sich die Ergebnisse für den Eichenwickler mit einer „isolation by distance“ erklären

    Wiedervernetzung von Lebensraumkorridoren über bestehende Bahntrassen (ICE, IC, Güterverkehr) : Ergebnisse des gleichnamigen F+E-Vorhabens des Bundesamtes für Naturschutz

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    Die funktionale Wiedervernetzung von Ökosystemen ist ein notwendiger und entscheidender Beitrag zur nachhaltigen Sicherung der Artenvielfalt. In der nationalen Strategie zur Biologischen Vielfalt 2007 ist formuliert, dass von Verkehrswegen bis 2020 in der Regel keine erheblichen Beeinträchtigungen des Biotopverbundsystems ausgehen (sollen). In der EU-Biodiversitätsstrategie 2030 ist formuliert, dass es für ein wirklich kohärentes und resilientes transeuropäisches Naturschutznetz wichtig sein wird, ökologische Korridore zu schaffen, um eine genetische Isolierung zu verhindern, die Migration von Arten zu ermöglichen und gesunde Ökosysteme zu erhalten und zu verbessern

    Vertical 3D GaN Nanoarchitectures towards an Integrated Optoelectronic Biosensing Platform in Microbial Fuel Cells

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    An integrated nano-optoelectronic biological sensor system is developed to obtain insights of the biochemical and physical processes of Geobacter sulfurreducens-based biofilm growth inside a miniaturized microbial fuel cell (MFC) reactor. Gallium nitride (GaN), which was used as a novel electrode material, has been investigated in terms of its biocompatibility and performance to transport the electrons delivered by the microorganisms. Moreover, in order to enhance the produced current density, vertical 3D GaN nanoarchitectures (i.e., arrays of nanowires and nanofins) with larger surface-to-volume ratios were fabricated using a top-down nanomachining method involving nanolithography and hybrid etching technique

    Community genetics in the time of next-generation molecular technologies

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    The EC-supported Network of Excellence Evoltree (http://www.evoltree.eu) formed a group of scientists involved in and actively contributing to Jointly Executed Research Activities on community genetics in forest ecosystems. In addition to the main authors, the group includes S. Augu-stin, M. Brandle, C. Burban, J. Burczyk, S. Cavers, I. Chybicki, C. Conord, E. Cremer, J. DeWoody, K. Donges, B. Fady,L. Karlinski, C. Kerdelhue, B. Kieliszewska-Rokicka, G. Kost, M. Kulczyk-Skrzeszewska, F. Lakatos, F. Lefevre, S.Liepelt, S. Oddou-Muratorio, K.-H. Rexer, M. Rudawska, M.Schadler, G. Taylor, K. Tuba, M. Viger, F. Villani, M. Villar.Understanding the interactions of co-occurring species within and across trophic levels provides key information needed for understanding the ecological and evolutionary processes that underlie biological diversity. As genetics has only recently been integrated into the study of community-level interactions, the time is right for a critical evaluation of potential new, gene-based approaches to studying communities. Next-generation molecular techniques, used in parallel with field-based observations and manipulative experiments across spatio-temporal gradients, are key to expanding our understanding of community-level processes. Here, we introduce a variety of ‘-omics’ tools, with recent studies of plant–insect herbivores and of ectomycorrhizal systems providing detailed examples of how next-generation approaches can revolutionize our understanding of interspecific interactions. We suggest ways that novel technologies may convert community genetics from a field that relies on correlative inference to one that reveals causal mechanisms of genetic co-variation and adaptations within communities

    Global Timber Tracking Network - The timber tracking tool infogram: Overview of wood identification methods' capacity

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    This is a guide to choose the best timber traceability verification method in the context of fighting against international illegal timber trade. The methods covered are 1) wood anatomy; 2) genetics; 3) stable isotopes; 4) direct analysis in real time - time-of-flight mass spectrometry (DART TOFMS); 5) near-infrared spectroscopy (NIRS); 6) Machine visio
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