This document summarizes various methods of asexual reproduction in fungi. It discusses reproduction through fission, budding, fragmentation, and different types of spore formation including sporangiospores, conidiospores/conidia, oidia/arthrospores/thallospores, chlamydospores, and blastospores. It provides examples of fungi that exhibit each type of asexual reproduction and includes diagrams to illustrate the various structures and processes involved. The document also briefly discusses other methods such as formation of sclerotia and rhizomorphs which allow fungi to survive unfavorable conditions.

1. Fungi – Asexual Reproduction
Dr C R Meera, M Sc; PhD,
Assistant Professor
Department of Microbiology
St Mary’s College, Thrissur-20
Kerala

2. FUNGI
 Reproduction by both Sexual and Asexual Methods
 Yeasts ( Eg:Cryptococcus neoformans) – Asexual (Budding, fission)
and sexual methods
 Yeast like fungi ( Eg: Candida albicans) – Asexual (Budding &
Fission)
 Molds : Both asexual and sexual methods
 Fungi imperfecti : Sporogenesis or Asexual Spore Formation
Sexual phase not defined

3. ASEXUAL REPRODUCTION IN FUNGI
 Somatic or Vegetative reproduction
 Asexual : No union of nuclei, sex cells or sex organs
1. Fission of somatic cells
2. Budding of somatic cells
3. Fragmentation
4. Spore formation

4. 1. Fission
Parental somatic
cell
Daughter cells
Karyokinesis (Nuclear division) followed by Cytokinesis (Cell
division)
Two identical daughter cells
Eg: Schizosaccharomyces pombe, also called "fission yeast"

5. 2. Budding
Parental somatic
cell
Daughter cells
 Somatic cells produce a small bud like out growth which develops
into a new individual
 Daughter cells pinch or bud from the parental cell
 Daughter cells are smaller than the mother cell
 Yeast cells divide once every 90 min
 Eg: Saccharomyces cerevisiae, Cryptococcus neoformans

6. 3. Fragmentation
 Disjoining of hyphal cells
 Disjoined single cells act as the spores
and germinate to produce hyphae and
mycelium
 Spores produced by fragmentation are called Oidia or
Arthrospores or Thallospore
Eg: Erysiphe

7. 4. Asexual Spore Formation
 Asexual spores are produced from single parental
cell
 Function : Dissemination of the species
 Mitospores : As these spores are produced by mitosis
 Pleomorphic or polymorphic fungi: Fungi that
produce more than one type of spores
 Sporophores : Special spore producing hyphae
 Name of this special hyphae changes according to the type of spore
produced on it.
Eg: Hyphae that produce Sporangiospores are called Sporangiophores
Hyphae that produce Conidiospores are called Conidiophores

8. EXOGENOUS SPORES
 Spores are either packed inside special sac-
like structures called Sporangium or at the
terminal ends
 Endogenous spores : Spores produced inside
the sporangia
 Exogenous spores: Spores on the terminal
ends of sporophores
 Sporangia is terminal or intercalary in their
position.
 Different asexual spores
a)Sporangiospores
b)Conidiospores or conidia
c)Oidia (Arthrospores/Thallospores)
d)Chlamydospores
e) Blastospores
ENDOGENOUS SPORES
Sporangium
Sporangiospores
Columella
Apophysis
Septum
Sporangiophore
Mycelium

9. a)Sporangiospores
 Single celled spores produced inside the special
sac-like structures called Sporangium (Sporangia
Pl.)
Eg:Mucor and Rhizopus
 Sporangiophores : Special hyphae producing
Sporangia
 Columella : Sterile dome-like structure at the tip
or within a sporangium
 Apophysis : Funnel-shaped swelling of a
sporangiophore, below the columella
 Sporangiospores can be motile or nonmotile
• Aplanospores : Non-motile sporangiospores
• Zoospores : Motile sporangiospores with flagella
Sporangium
Sporangiospores
Columella
Apophysis
Septum
Sporangiopho
re
Mycelium

10. b)Conidiospores or conidia
• Exogenous spores formed at the tip
or side of hyphae
• Two Forms :Microconidia and
Macroconodia
• Microconidia: Small single celled
conidia
• Macroconidia: Large multi celled
spores.
• The conidia are produced singly
Eg: Phytophthora
• or in chains at the tips of the
conidiophores Eg: Aspergillus
• or at the tips of their branches
Eg: Penicillium

11.  Oidia and Chlamydospores : single celled
spores produced by the disjoining or
fragmentation
 Oidia : Hyphal cells disjoin from the apical
regions and each fragmented cell acts as
spore.
Eg: Erysiphe
 Chlamydospore : Hyphal Cells become
enveloped by a thick wall before
fragmentation
 Chlamydospores can be terminal or
intercalary & are highly resistant to adverse
conditions
Eg. Mucor, Fusarium
C & d) Oidia/ Oidium (Arthrospores/Thallospores) and Chlamydospores
Chlamydospore
Oidium

12. e) Blastospores
 Blastospores : Spores formed by budding
 Also known as a blastoconidium (pl. blastoconidia)
 Eg: Candida albicans
Blastospores
Chlamydospores
Pesudomycelia

13. Other Methods of Asexual Reproduction
 Formation of Sclerotia and Rhizomorphs
 To overcome unfavourable environmental conditions
 Structures of perennation and vegetative propagation
 Sclerotia : Claviceps (Ergot) produce an interwoven
compact form of mycelium surrounded by hard
covering and is called sclerotium
 Round, cylindrical, cushion shaped or irregular with
a dense mass of thick walled hyphae
 Rhizomorphs : Rope-like modified mycelium
 Both forms remain dormant during adverse
conditions and can survive for many years
 They give rise to new mycelia on the return of
favourable conditions

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