Michael Bacht
PhD student
office C 2064
tel: +49(0)6421 28 23490
fax: +49(0) 6421 28 23387
michael.bacht[at]biologie.uni-marburg.de
DNA barcoding, population genetics, sequencing, mtDNA, climate change, ring ouzel, Turdus torquatus, english oak, Quercus robur, ectomycorrhizal symbiosis, Piloderma croceum, Gypsy moth, Lymantria dispar, herbivore- plant- interaction, plant- animal- microflora interactions
PhD thesis: Multitrophic interactions in an ectomycorrhiza-plant-insect herbivory system – plant gene expression, resource allocation and performance of plants and herbivores
Mycorrhizal fungi and insect herbivores are important determinants of plant growth and ecosystem functioning. Further, mycorrhizal symbioses have been shown to be important for plant interactions with herbivores, but the underlying mechanisms are still poorly understood. Recent research provides circumstantial evidence that these effects may be triggered by interacting effects of mycorrhiza and herbivory on expression patterns of genes related to plant metabolism and defence as well as the allocation of resources within the plant-fungus system. Further, the effects of mycorrhiza on plant growth are contingent on the activity of other associated microorganisms, but their potential influence on plant interactions with herbivores is unknown. Here we propose to use the well characterized Quercus robur- Piloderma croceum system to study the interacting effects of mycorrhization and insect herbivory by Lymantria dispar on plant growth, gene expression patterns and resource allocation. The integration of molecular genetics, plant physiology and experimental ecology provides a novel and innovative approach for the study of multitrophic interactions and will yield fundamental information on the mechanisms and ecological consequences of the ectomycorrhizal symbiosis. We will further assess the importance of mycorrhizosphere actinomycetes and their interactions with mycorrhizal fungi for plant-insect herbivore interactions.
www.trophinoak.ufz.de
Master thesis: Genetic divergences in Ring Ouzels (Turdus torquatus) of the European low mountain ranges
The influence of climate change on species is undeniable. Especially species with alimited possibility for range shifts are highly endangered to extinct induced by climate change. Due to the distribution limited to mountains and low mountain ranges the Ring Ouzel was chosen as a case study. Through geographical distance, the populations should be genetically differentiated from each other. In case of extinction of local populations it would not only be the loss of populations, but also the loss of genetic variability and of potential evolutionary significant units. Here I show that there is genetic variation in the cytochrome b gene, between the populations in the Alpes and the populations of the low mountain ranges. By this I found three mutations compared to the main haplotype in the population of the Thuringian Forest, which is extinct by now. This study also gives an indication of introgression from one population into another. My results reveal the value of low mountain ranges populations due to their genetic variability and their extinction risk caused by climate change.
Bachelor thesis: DNA barcoding: developing a molecular threshold for rapid diversity assessment in termites
Because of the progressive loss of biodiversity on the one hand and a still fragmentary knowledge of species composition in many ecosystems on the other hand we need tools for a rapid biodiversity assessment. The method of DNA Barcoding could be such a tool to enforce the endeavour for completing the “Encyclopaedia of Life” on earth. Especially for taxa, like the termites, with fairly similar morphological features among species and therefore a high possibility of the occurrence of cryptic species, we need approaches for fast identification. The DNA barcoding approach was tested in this work for termites using the mitochondrial COII gene. I tried to figure out a threshold for species delimitation which could help others to define MOTUs (Molecular Operational Taxonomic Unit) for diversity assessment or even taxonomic projects. Available termite sequences of the COII gene were received from the online database GenBank. Thresholds for species delimitation were defined for each of the seven families of the order Isoptera and the success of these thresholds was determined. The family thresholds and even the threshold, which were calculated over the whole order gives a good success. The threshold to discriminate species was about 0.05 of K2P distance with an identification success of about 90 %. The Threshold for genera discrimination was about 0.14 of K2P distance also with a high success of about 90 %. In this work it was showed, that it makes sense to work with molecular divergences in ecology.
Teaching
Geländeübungen zur biologischen Vielfalt
Artenkenntnis Zoologie
Ansprache von Tieren im Gelände
