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Towards understanding the coevolution of the MaizeExserohilum pathosystem
06 Juni
17:00 Uhr - 18:00 Uhr
Institute for Genetics, lecture hall, 4th floor
Zülpicher Str. 47a
50674 Cologne

Link: http://lageplan.uni-koeln.de/#!301


Seminar  in Probabilistic Structures in Evolution.

Speaker: Karl Schmid, Universität Hohenheim

The rapid evolution of plant pathogens is a hallmark of human agriculture and is favored by a high spatial homogeneity, reduced biodiversity in agricultural landscapes. Modern farming farming practices resulted in strong selective advantage of resistant genotypes that leads to rapid evolution. In response, multiple instances of resistance evolution in pathogens occurred. A key question is therefore whether evolution in modern agricultural systems can be managed by agricultural practices that are based on evolutionary principles which consider that crops and their pests are in an asymmetric relationship because of different effective population sizes, mutation rates and generation times. Population genetic modeling using coalscentbased approaches does not indicate evidence for strong selection of advantageous genotypes (i.e., sweepstake reproduction) and also shows that the same race evolved independentl  in different clonal lineages. A metagenomic analysis of the pathogen from a single field identified both mating types and different clonal lineages within a short geographic distance and some evidence for outcrossing. In summary, E. turcicum has a complex genetic history that is mainly determined by asexual reproduction in the recent past, but also shows evidence for historicaland geographically restricted (in the tropics) sexual reproduction. For these reasons, analyses of selection by coadaptation need to account for this history and also requires largescale sampling at different geographic scales.

Joachim Krug, Institut für Biophysik und
Thomas Wiehe, Institut für Genetik