Format: ORAL

Marcus A. Koch

Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, Heidelberg, Germany

Gladiolus palustris (marsh Gladiolus) of wet grasslands is an extremely rare and highly endangered species in Central Europe. Ongoing loss of habitat, population fragmentation, drought, and higher mean annual temperatures caused by global warming have all contributed to a severe decline in its population over the past few decades. Additionally, hybridization with other species, such as G. imbricatus and G. illyricus, and genetic depletion may pose a significant threat to the species survival. The focus here is set to characterize major gene pools of the species in southern and southwestern Germany and illustrate that past hybridization and introgression in Central Europe are more extensive than previously thought, posing a challenge to conservation strategies targeting taxonomically defined species. A parallel exploration into the water plant Nuphar pumila, a post-glacial relic in Central Europe, sheds light on the diverse signs of introgression from the widespread Nuphar lutea. These genetic imprints serve as historical markers, reflecting centuries-old processes and changes in the landscape. Contrary to expectations, hybrid gene pools did not invariably result in intermediate morphologies. Instead, introgression appears to have played a pivotal role in enabling these species to adapt to evolving environmental conditions, such as heightened nitrogen levels and water temperatures. Given the longstanding presence of these populations in the region and their vital contribution to the active gene pool, the evidence suggests a need to champion and safeguard these populations. In light of these findings, it is proposed that conservation efforts should also prioritize naturally occurring hybrids and introgressed populations. Recognizing their resilience and adaptive capabilities, these populations emerge as crucial custodians of biodiversity, embodying the intricate dance between genetic diversity and environmental change.