1. Joint effects of demography and natural selection on the molecular evolution of wild tomatoes: I am collaborating with Dirk Metzler at the LMU-Munich to understand the population genetic history of wild tomatoes. We are developing evolutionary genetic models to account for the population substructure and speciation history of this group of closely related tomato species. These models will help us define the appropriate null model against which we can examine patterns of molecular evolution for a suite of candidate genes in stress response pathways. An ultimate goal is to determine the role of natural selection in shaping sequence and functional diversity for this and other gene classes in tomato and other species. This work has been funded by the DFG since 2008.

2. Evolution of resistance genes in wild tomato species: In a series of projects we have combined population genetic studies of well-characterized pathogen resistance genes with functional studies involving plant transformation and pathogen infection studies. My collaborators on this work include Chuck Langley, Richard Michelmore at UC Davis, USA, Wolfgang Stephan and Thomas Lahaye at the LMU-Munich and Renier van der Hoorn at the MPI for Plant Breeding in Cologne, Germany. This work has been funded by the DFG since 2005.

3. Coevolution of Arabidopsis and Hyaloperonospora: In collaboration with Jim Beynon and Eric Holub at Warwick Horticultural Research Institute, we are investigating protein sequence variation and molecular evolution at the RPP13 locus within A. thaliana and the ATR13 and ATR1 loci within H. parasitica.

4. Evolution of symbiosis genes in Lotus species: In a collaboration with Martin Parniske at the LMU-Munich we are studying a suite of symbiosis genes in European and Asian species of Lotus. In this project, we combine population genetic studies, phylogenetic studies and functional work to determine the types of selection that have operated on these loci and to understand how natural variation at particular candidate loci affects the interspecific interaction between host and symbiont. This work has been funded by the DFG since 2008.