10 public questions tagged with this topic.
A large number of Deuteromycetes are decomposers of litter. By breaking down this material, they help return mineral nutrients to the environment and therefore contribute to mineral cycling.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Fungi - Deuteromycetes and Economic Importance
Alternaria, Colletotrichum and Trichoderma are examples of Deuteromycetes. Members of this group reproduce by asexual spores called conidia.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Fungi - Deuteromycetes and Economic Importance
Deuteromycetes contain fungi whose sexual stages are not known. Once the sexual stage is discovered, the fungus is transferred to the appropriate class. Production of basidiospores identifies the sexual form as a Basidiomycete.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Fungi - Phycomycetes Ascomycetes Basidiomycetes
Deuteromycetes contain fungi whose sexual stages are not known. Once a sexual stage is discovered, the fungus is moved to the class to which that stage belongs. Production of ascospores identifies the sexual form as an Ascomycete.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Fungi - Phycomycetes Ascomycetes Basidiomycetes
Most deuteromycetes propagate asexually through conidia, non-motile mitosporic propagules produced exogenously on differentiated hyphae termed conidiophores through blastic or thallic development. Conidial types include microconidia, macroconidia, phialospores formed from phialides, porospores through pores, arthrospores via fragmentation, often multicellular, melanized, ornamented favoring airborne dispersal and stress tolerance. No ascospores, basidiospores, zygospores or flagellated zoospores develop due to absence of meiosporangia. Genetic variation arises via parasexual cycle involving heterokaryosis, diploidization and mitotic crossing over plus mutation ensuring adaptability despite lack of meiosis.
Ref: NCERT Class 11 Chapter 2 Fungi; Alexopoulos Introductory Mycology Form-class Deuteromycetes
Deuteromycetes traditionally designated Fungi Imperfecti represent artificial form-group where sexual teleomorphic phase remains undiscovered despite extensive culture attempts, so classification relies on asexual anamorph characteristics solely. Lack of ascocarps, basidiocarps or zygosporangia means primary taxonomic criteria of sexual reproduction cannot apply. Mycelium usually septate with dolipore or simple septa, reproduction via conidia or sterile mycelia only. Molecular phylogenetics using ITS, LSU rDNA now nests most deuteromycetes within Ascomycota and Basidiomycota indicating secondary loss of sexuality, yet practical identification continues using absence of observed sexual reproduction as diagnostic imperfect designation.
Ref: Webster & Weber Introduction to Fungi 3rd ed. Deuteromycetes; Campbell Biology 12th ed. Chapter 31
While some members of Deuteromycetes are indeed saprophytes or parasites (causing diseases like early blight of potato), the NCERT text emphasizes their broader ecological importance. It states that a large majority of them function as vital 'decomposers of litter'. By breaking down fallen leaves, dead wood, and organic debris, they significantly help in essential mineral cycling within terrestrial ecosystems.
Ref: NCERT Class 11 Biology > Chapter 2: Biological Classification > 2.3 Kingdom Fungi
Because Deuteromycetes are defined by their lack of known sexual reproduction, they rely entirely on asexual mechanisms to propagate. The NCERT textbook specifies that members of Deuteromycetes reproduce asexually exclusively by producing spores called 'conidia'. These are exogenously produced spores, similar to those found in Ascomycetes, hinting at their close evolutionary relationship before their sexual stages are confirmed.
Ref: NCERT Class 11 Biology > Chapter 2: Biological Classification > 2.3 Kingdom Fungi
According to the NCERT textbook, Alternaria, Colletotrichum, and Trichoderma are the prime examples explicitly listed under the class Deuteromycetes (imperfect fungi), where many act as critical decomposers of litter. In sharp contrast, Ustilago (which famously causes smut disease in crops) and Puccinia (causing rust) are standard examples provided under the class Basidiomycetes. Therefore, Ustilago does not belong to Deuteromycetes.
Ref: NCERT Class 11 Biology > Chapter 2: Biological Classification > 2.3 Kingdom Fungi
Deuteromycetes act as a temporary taxonomic placeholder in mycology. According to NCERT, they are famously termed 'imperfect fungi' strictly because only their asexual or vegetative phases of reproduction are currently known. The 'perfect' (sexual) stages have either not yet been discovered or may have been lost evolutionarily. Once the sexual stage of a member is discovered, it is properly reclassified to Ascomycetes or Basidiomycetes.
Ref: NCERT Class 11 Biology > Chapter 2: Biological Classification > 2.3 Kingdom Fungi
