Spore discharge

Spores that have a dispersal function can be released from their parent mycelium by active or passive mechanisms. As several spores are wind-dispersed they are produced in dry friable masses that are passively discharged by wind.  Other spores are passively discharged through water droplets splashing spores away from parent mycelium.

        Figure  8.  (a) Passive  and  (b) active  spore discharge; (c) ascospore discharge; (d) basidiospore discharge.

Fungal spores can be actively discharged by explosive mechanisms. These mechanisms use a combination of an increasing turgor pressure within the spore-bearing hypha, combined with an inbuilt weak zone of the hyphal wall. This ensures that when the hypha bursts the spore discharge is directed for maximum distance. Asci are usually dispersed in this way, and a few sporangia too. Basidiospores are also actively discharged.