Oospore

Not to be confused with Oogamy
Oospores of Hyaloperonospora parasitica, agent of the downy mildew (in the middle)

An oospore is a thick-walled sexual spore that develops from a fertilized oosphere in some algae, fungi, and Oomycetes.

In Oomycetes, oospores can also result from asexual reproduction, by apomixis.[1]

References

  1. Lamour, K.; Kamoun, S. (2009). Oomycete Genetics and Genomics: Diversity, Interactions and Research Tools. Wiley. ISBN 9780470475881.