Learn about the comparison between phycomycetes and ascomycetes.
Most Phycomycetes are aquatic and even the terrestrial ones have aquatic tendency. They are largely saprophytic than parasitic. Reverse is the case with the Ascomycetes where very few- species are true aquatic. They are mostly parasites of varying degree.
In the Phycomycetes it is very simple being composed of unicellular uninucleate, ill-developed mycelium to well-developed aseptate mycelium. In the Ascomycetes the mycelium in septate and may be developed to form plectenchymatous structures being differentiated into prosenchyma and pseudoparenchyma.
In a large number of Phycomycetes asexual reproduction takes place by the development of flagellate spores which are borne in sporangia. But in the Ascomycetes such spores are non-flagellate and are not developed in sporangia.
In many of the Phycomycetes sexual reproduction takes place by the formation of well-organized gametes developed in gametangia. But in the Ascomycetes there is usually absence of any such structure. Here the gametangia instead of bearing well-organized gametes contain nuclei embedded in a mass of cytoplasm.
In the Phycomycetes karyogamy follows immediately after plasmogamy. Whereas, in the Ascomycetes there is interval between plasmogamy and karyogamy which is occupied by a phase of dikaryotic condition. Here sexual reproduction leads to the development of a fruiting structure composed of fertile and sterile tissue which is altogether absent in the Phycomycetes.