Pythium aphanidermatum is a plant pathogen causing damping off, root and stem rots, and blights of grasses and fruits. P. aphanidermatum have wide rage of hosts, including the economically important crops like beets, pepper and cotton. It is a major cause of root rot in papaya. It requires warmer temperatures, it is often seen in greenhouses. P. aphanidermatum is responsible for pre and post emergence damping off. Pre-emergence damping off is when the seed is infected prior to germination. This can result in poor or no germination, and is observable as a browning or rotting of the seed. Post emergence damping off takes place after germination and results in a thinning, water-soaked stem near the plant collar, which eventually causes the collapse of the plant.

It belongs to the group oomycetes which was originally classified among the fungi, due to its morphological and functional similarities. They are now classifed as protists based on modern insights on phylogentic relationship with photosynthetic organisms such as brown algae and diatoms.

Browse this genome in the Ensembl Genomes website.