Principal Investigators: Dominik Begerow and Kathrin Otte 

PhD candidate:  Maximiliana Dürig 

This project investigates how the population genomics of selected Ericaceae species and their highly specialized fungal parasites of the genus Exobasidium in Northern Europe have changed over the past 200 years. Peatlands, important carbon sinks and climate regulators, have been massively reduced through land conversion, causing severe declines in characteristic plant species such as Ledum palustre, Andromeda polifolia, and various Vaccinium species, as well as their parasites. Many of these species are now listed as threatened in Germany. 

Using historical herbarium collections spanning two centuries alongside recent samples from Northern and Southern Germany, the project examines the evolutionary history of three plant–parasite species pairs. Two pairs are restricted to peat bogs (Andromeda polifolia infected by Exobasidium karstenii and Vaccinium oxycoccus infected by E. rostrupii), while one also occurs in forests (Vaccinium myrtillus infected by E. arescens), representing different ecological niche sizes. Through advanced genomic techniques such as hyRAD sequencing and Oxford Nanopore technology, the team will analyze genetic diversity, past and present population sizes, and gene flow across time. 

The key research questions concern the influence of narrow ecological niches on genetic depletion, the risk of extinction for hosts and parasites due to shrinking population sizes, and random genetic changes caused by bottleneck effects. Five work packages cover the collection and sequencing of the material, phylogenetic and population genetic analyses, and modelling of future adaptability.

Ultimately, the project aims to determine how resilient peatland plants and their specialized parasites are to environmental change. In collaboration with AI experts from HCDS (Biemann Group), new tools will be developed to predict future evolutionary trajectories, contributing to a deeper understanding of ecological dynamics and biodiversity loss in endangered habitats

Foto: Maximiliana Dürig