Pycnidia

Pycnidia of Mycosphaerella graminicola embedded in the leaf tissue and still closed

The pycnidia  - singular pycnidia or pycnidium  - are spherical to bottle-shaped fruiting body -like structures (also known as fructifications) that occur in the group of pouches . Asexual spores ( conidia ) are formed inside them . Spores that arise in pycnidia are often called pycnospores.

Pycnidia are often found in lichens (i.e. lichenized sac fungi), where they are usually sunk into the bed of the lichen and often only their tiny, superficial opening, the ostiolum , is visible.

In non-lichenized Ascomycetes , the pycnidia are more or less sunk into the host tissue. These sac fungi form the form taxon of the order Sphaeropsidales . These include important pathogens for plant diseases such as Ascochyta chrysanthemi or Phoma lingam .

Similar structures in rust fungi do not form conduits, but spermatia , which are used to transmit genetic information (DNA). They are therefore called spermogonia .

literature

• Heinrich Dörfelt (Ed.): Lexicon of mycology. Gustav Fischer, Stuttgart et al. 1989, ISBN 3-437-20413-0 .