Smut fungi are biotrophic and compose a large group of plant pathogens where the speciation seems to be closely connected to their specific host range. This project aims to elucidate on the molecular level “host jump” enabling and therefore host range influencing factors in the smut fungus Ustilago bromivora and related smuts by genetics and genome wide comparisons. Therefore the genomes of Ustilago hordeaceus and Ustilago diandrus are sequenced and annotated for subsequent comparative analysis with the available U. bromivora and other genomes.