Fungi contain multitudes: Tempo and modes of evolution in the purplepore bracket fungus Trichaptum

Abstract

Evolution has brought to life an immense diversity of forms, lifestyles and species in the fungi. Yet our knowledge about how this diversity has been generated remains sparse. I have taken a closer look at evolution in a group of wood decay fungi in genus Trichaptum, with the aim of gaining more insight about the speciation process in fungi. Trichaptum species are common, easy to culture, and can be crossed in the lab. Moreover, they have varying degrees of reproductive barriers, and these attributes make them suitable for speciation studies as the development of reproductive barriers is central to the speciation process. I have established a comprehensive culture collection that have been put through crossing experiments and whole genome DNA sequencing to investigate the evolutionary history of different Trichaptum lineages and the genetic causes of their reproductive barriers. Analyses of the sequenced genomes revealed multiple hybridization events, which speaks to the importance of reticulate evolution in these fungi. The studies cover evolution in genus Trichaptum at multiple scales, from the relatively recent changes occurring within Europe in T. abietinum, to changes that have happened between continents and distinctly differentiated species across larger time spans. Altogether this work demonstrates how multiple evolutionary forces across different temporal and genetic scales have interacted to shape the current diversity and genomic landscape in Trichaptum.