behaviour. Not all fungi reproduce sexually and many that do are isogamous; thus, for many members of the fungal kingdom, the terms "male" and "female" do not apply. Homothallic species are able to mate with themselves, while in heterothallic species only isolates of opposite mating types can mate.

Mating between isogamous fungi may consist only of a transfer of a nucleus from one cell to another. Vegetative incompatibility within