Appressorium morphogenesis and cell cycle progression are linked in the grass powdery mildew fungus Blumeria graminis

► Early nuclear migration is promoted by the presence of very-long-chain aldehydes. ► Uninucleate conidia undergo a single round of mitosis after inoculation. ► Mitosis and cytokinesis are spatially uncoupled. ► Mitosis and cytokinesis are prerequisites for appressorium formation. ► Development of an improved in vitro system.