Fungi Classification - Ascomycetes

Description:

Ascomycetes are also called sac fungi. They include a diverse group consisting of over 30,000 species. The characteristic features of Ascomycetes are as follows −

• Mycelium has septate hyphae. Yeast are unicellular and may form filamentous structure called pseudomycelium.

• The septa possess central pores called septal pores. It helps in communication between adjacent cells.

• Spores are produced in sac shaped structures called asci.

• Reproduction happens asexually by budding or by spores called conidia that develop at the tips of certain hyphae.

• Sexual reproduction in ascomycetes may occur.

• In some fungi male and female sex organs are differentiated.

• Fertilization occurs in two steps- plasmogamy and karyogamy.

• When karyogamy is delayed after plasmogamy, a new transitional phase appears in the life cycle called dikaryophase. Such cells possess two nuclei.

• Some dikaryotic cells function as ascus mother cells which later act as the seats of both karyogamy and meiosis.