Kingdom fungi are one of the most primitive organisms on earth. They are a kingdom of organisms that are heterotrophic and are decomposers of dead matter. There are four classes broadly in kingdom fungi: phycomyctes, ascomycetes, basidiomycetes and deuteromycetes . The ascomycetes is by far the largest group and constitutes most of the fungi.
Fungi are essential in decomposition processes. They are mostly saprophtes but some can be parasitic. Saprophytes obtain their carbon and energy from dead organic matter. Saprophytes are essential in the decomposition of dead matter. Saprophytes are heterotrophic organisms.
Importance of Fungi
- The hyphae of the fungus also absorb water from the soil. The water is transported through the hyphae of the fungus to the plant.
- Some fungus also acts as pesticides, while some are parasitic like puccinia, smut etc.
- Yeast is a unicellular fungus which is used in the formation of bread and bear.
- Symbiotic association between fungus and roots of higher plants leads to the formation of mycorrhiza
- Lichens are formed by mutual association of algae and fungus, which act as an air pollution indicator.
- Some fungus like Penicillin are source of antibiotics.
- Humans use the extracellular enzymes produced by fungi in the commercial production of enzymes. The enzymes produced by fungi are used in making laundry detergent.
Fungus is divided into four classes
Ascomycetes are also known as sac fungi. They grown on dead and decaying matter. They are coprophillous. Their hyphae is branched and septate. They are parasitic, saprophytic and symbiotic. They reproduce vegetatively by fragmentation, budding and fission. They bear exogenous non-motile spore called conidia on conidiophore. Their sexual spores are endogenous and present inside ascus on ascocarp. Some common examples of ascomycetes are Neurospora, Claviceps, Morels, Truffles, Penicillium, Yeast, Aspergillus and Penicillium etc.
Phycomycetes are also known as algal fungi. They grown on dead and decaying matter. Mostly they are aquatic. They have aseptate hyphae. They are saprophytic as well as parasitic. They reproduce vegetatively by fragmentation and asexually by formation of spore like structure inside sporangia known as sporangiospore. The sporangiospore can be motile zoospore and non motile aplanospore. Some common examples of phycomycetes are Mucor, Rhizophus and Albugo, etc.
Basdiomycetes are also known as club fungi or shelf fungi. Basidiomycetes are decomposers and they grow on dead and decaying matter. They grow on wood that is why they are also called as Epixylic. They have a septate and branched hyphae. They may be parasitic, saprophytic and symbiotic. They reproduce vegetatively and sexually . Vegetatively by fragmentation, sexually by somatic fusion of hyphae. Asexual spores are absent in basidiomycetes. Some common examples of basidiomycetes are Ustilago, Puccinia and Agaricus.
Deutereomycetes are also known as fungi imperfecti. They grow on dead and decaying matter. They help in mineral recycling. They have septate hyphae. They are parasitic and saprophytic. It is a temporary group for those fungi whose sexual reproduction is not discovered yet. They reproduce by fragmentation. They form conidiospores as asexual spore. Some common examples of deutereomycetes are Alternaria, Colletotrichum, Trichodera, and Fusarium.