Spore liberation in Sporobolomyces in relation to light*

In the pink yeast Sporobolomyces roseus spore discharge can occur in continuous light or continuous darkness. However, with a 12-h light: 12-h dark regimen, discharge is periodic with the maximum rate in the dark period. In inducing periodicity blue light is effective but not yellow. Both a white mutant and a normal culture with carotenoid production inhibited by diphenylamine respond to periodic illumination in the same way as normal pink colonies.