Monitoring of germination by microscopy

CuSO₄-treated spore suspensions were spotted on objective slides (µm dish 35 mm; IBIDI, Planegg, Germany). After freezing them for 20 min on a metal block to avoid spreading of the liquid, they were covered with a thin (<2 mm) layer of PD agar or 1.5% water agar, respectively. After a 15–17 hr incubation at 21°C, the picture acquisition was performed with an inverted microscope (Zeiss Axiovert 200 M with 40×/1.3 Plan-Neofluar Oil objective). Picture acquisition occurred every 20 min. Image processing was done with Fiji Imaging software.