Molecular evolution of plant defence in wild tomato species

Understanding adaptation of plants to pathogens is of vital importance to create durable resistance in crops. Therefore, we are interested in understanding the evolution of pathogen resistance in relatively short time scales. We study different populations from a diverse and geographically differentiated tomato species, Solanum chilense. We have shown that populations show different levels of defence against a range of pathogens and also show patterns of differential selection for defence-associated genes. We now want to link these observation to the molecular defence mechanisms involved. In this project we test the differences in early defence responses between plants and try to identify the causal genes. This way we hopefully learn, not just more about the diversity of pathogen defence mechanisms in plants, but might also identify new genes underlying these responses.

This project is funded through SFB924

Pathogen evolution

SPiRaSOL: Sampling Phytophthora Infestans and Ralstonia spp from wild solanum

Besides getting a good understanding of how plants evolve to fend off their pathogens, it is equally important to understand how pathogens evolve to maintain their virulence on plants.
This small, exploratory project in collaboration with Dr. Philippe Prior and Dr. Hannele Lindqvist-Kreuze focused on optimising sampling methods for two very important pathogens on potato and tomato in the field. We focus on sampling methods for various wild Solanum species. Two visits to Peru have taught us a lot about the local field circumstances, the different wild tomato species and their pathogen symptoms. Unfortunately, Philippe passed away in November 2018, leading to an early termination of the project.

This project was funded through the Agropolis Fondation

Pathogen adaptation to host and climate

The wild tomato species Solanum chilense grows in southern Peru and northern Chile and covers a wide range of habitats from the coast and central plains (1500-2000 m altitude) to truly mountainous  terrain (>2500 m altitude). In this project we look at the occurrence of different phytopathogens and their genetic make up throughout the whole species range of S. chilense, to understand how specific pathogens adapt to host and climate. This project is a collaboration with Prof. German Sepulveda at the University of Tarapaca in Chile and  Soledad Gamboa and the CIP, Lima in Peru.

This project is funded through the German Science Foundation

Population genomics of Ramularia collo-cygni

Ramularia collo-cygni is a recently emerging pathogen on Barley. It has only been really noticed as a pathogen  since the mid 1980s, partly due to the difficulty to distinguish it from other stresses in the field and because of its long latent phase.
This project, in collaboration with Dr. Michael Heß, Prof. Ralph Hückelhoven, Dr. Martin Münsterkötter and Dr. Ulrich Güldener, aims at unraveling the genomic diversity of Ramularia collo-cygni in the field in order to understand which factors contribute to its recent emergence as a pathogen on Barley. Initial invesitigions focused on creaing a useful reference genome. In a second part we analysed 20 strains of the pathogen from a global collection. We found that the pathogen globally intermixed (due to shipping of contaminated seeds) and possibly capable of sexual reproduction. Many Ramularia collo-cygni strains show signs of fungicide resistance. Our findings thus suggest that the current epidemic might grow much larger, of we don’t find clever ways to combat this pathogen.

This project was in part funded through BayKlimaFit