The lower fungi comprise the simplest and the primitive group of true fungi which lack septum in the hyphae and primarily reproduce by sporangiospores.
The majority of these are aquatic (Saprolegnia), some are amphibious (Phytophthora) and some terrestrial (Rhizopus).
- The somatic phase consists of either a unicellular thallus or a non-septate coenocytic mycelium. The septa usually remain suppressed in the actively growing stage.
- Asexual reproduction takes place by sporangiospores and sometimes by conidia. The sporangiospores are motile (zoospores) in aquatic species and non-motile in the terrestrial species.
- The spore producing units are usually not grouped into a complex fructification.
- Sexual reproduction, when present, is either isogamous or heterogamous.
- Karyogamy generally follows plasmogamy almost immediately so that there is no dikaryophase in the life cycle.
4 classes found under lower fungi.
The fungi group with hyphae well-developed, septate, and usually at some stages of development interwoven into a compact tissue especially in the fruiting body (as in ascomycetes, basidiomycetes, and imperfect fungi) is called higher fungi.
- No motile cells are produced in the life cycle.
The higher fungi comprises of following three classes:
- Class Ascomyecetes
- Class Basidiomycetes
- Class Deuteromycetes
Differences between lower fungi and higher fungi
|Character||Lower fungi||Higher fungi|
Differences between ascomycetes and lower fungi
- The characteristic spores of the sexual or perfect stage are endogenous in origin and are called the ascospores.
- They are produced within special, sac-like structures called the asci.
- Plasmogamy takes place by the fusion of gametangia or somatic hyphae.
- Somatic phase is usually a septate mycelium which multiplies asexually by conidia; rarely it is unicellular (as in the yeasts) and is propagated by budding or rarely by fission.
- The characteristic spores of the sexual or perfect stage are exogenous in origin and are called the basidiospores.
- They are borne externally usually on club-shaped structures called basidia.
- The somatic phase consists of a simple or complex mycelium with or without clamp connections.
- Sexual organs are lacking.
- Plasmogamy, however, takes place by hyphal fusion.
Examples: Agaricus, Amanita etc.
- Included in this class are the higher fungi in which the sexual or perfect stage is unknown.
- The somatic phase consists of a septate mycelium which multiplies asexually by conidia.
- The conidia are produced on conidiophores which may occur isolated or may be aggregated to form complex structures such as synnema, pycnidia and acervuli.