Zygomycetes : The Conjugation Fungi | Structures & Characteristics
- It is class of terrestrial fungi which are mostly saprotrophic and rarely parasitic.
- Hyphal wall contains chitin or fungal cellulose.
- The mycelium is coenocytic (multinucleate, aseptate) like the one found in Oomycetes.
- Motile cells (zoospores or planogametes) are absent.
- Mitospores are non motile. They are called sporangiospores as the spores are formed inside sporangia that are borne at the tips of special hyphae called sporangiophores.
- Sexual reproduction occurs through gametangial copulation or conjugation. Because of it, zygomycetes are also called conjugation fungi.
- The gametes are commonly multinucleate and are called coenogametes.
- Sexual reproduction produces a resting diploid spore called zygospore. Because of the presence of zygospore, the group of fungi is called zygomycetes. Zygospore differs from oospore in that, for its formation a distinct food laden, non motile, large female gamete is not produced.
- Zygospore is the site of meiosis and does not give rise to new mycelium directily. Instead it produces a new sporangium called germ sporangium (previously called zygosporangium). Germ sporangium forms meiospores called germ spores.
- Sometimes, gametangia fail to fuse. Gametangia become surrounded by a thick wall resulting in formation of azygospore (parthenogenetically produced zygospore).