This video is about sexual reproduction in fungi. Sexual reproduction methods like Gametic copulation, Gamete-Gametangial copulation, Gametangial copulation, Somatic copulation and Spermatization are detailed well. Different sexual spores like ascospores, basidiospores, zygospores and oospores, their formation and properties are explained.

1. SEXUAL REPRODUCTION IN
FUNGI
Dr C R Meera, M Sc; Ph D,
Assistant Professor
Department of Microbiology
St Mary’s College, Thrissur-20
Kerala

2. Reproduction in Fungi
Asexual
Fission of somatic cells
Budding of somatic cells
Fragmentation
Spore formation
Sexual
Gametic copulation
Gamete-Gametangial copulation
Gametangial copulation
Somatic copulation
Spermatization
 Spores germinate to give rise to new fungi
 Homothallic fungus are able to mate with themselves, while
in heterothallic fungus, opposite sex cells are in different individuals.

3. Fungal spores
Asexual Spores
a)Sporangiospores
b)Conidiospores or conidia
c)Oidia (Arthrospores/Thallospores)
d)Chlamydospores
e) Blastospores
Sexual Spores
a) Ascospores
b) Basidiospores
c) Zygospores
d) Oospores

4. Sexual Reproduction
 Fusion of compatible nuclei of
two parental cells
 Sexual reproduction –
Plasmogamy, Karyogamy,
meiosis
 Plasmogamy – Fusion of
protoplast
 Karyogamy – Fusion of haploid
nuclei of two mating types
 Meiosis – To reduce the diploid
chromosome number to
haploid

5. Sex organelles of Fungi
 Sexually different fungal hyphae
are called + and – strain
 Sex organelles are called
Gametangia (Gematangium)
 Gametangium – May
differentiate into Gametes
Or may contain one or more
gamete nuclei
 Male gametangium is called
Antheridium (Antheridia)
 Female gametangium is called
Oogonium (Oogonia)
Oogonium
Antheridium

6. 1. Gametic copulation
2. Gamete-Gametangial copulation
3. Gametangial copulation
4. Somatic copulation
5. Spermatization
Sexual Reproduction Methods

7.  Gametic copulation - fusion differentiated, uninucleate sexual cells or gametes
formed in gametangia to form spores
 One or both gamates are motile
 Isogametes- the two members of the fusion pair are alike- Isogamy
 Heterogametes/Anisogametes- morphologically different gametes-
Heterogamy/Anisogamy
1. Gametic copulation
ISOGAMY
HETEROGAMY

8. 2. Gamete-Gametangial copulation
Two gametangia come into
contact, but no fusion
between cells
Female gametangium
contains differentiated female
gametes
Male nucleus migrates
through fertilization tube or
pore into female
gametangium to form spore

9. 3. Gametangial copulation
Male Gametangium
Female Gametangium
No gametangial differentiation into gametes
Two gametangia fuse to give rise to a zygote which
develops into a resting spore

10. 4. Somatic copulation
Sexual fusion of undifferentiated
somatic or vegetative cells
No differentiation of hyphae into
gametangia

11. 5. Spermatization
Union of special male structure
called Spermatium (Pl. Spermatia)
with female receptive structure
During plasmogamy, spermatia
empties its contents into receptive
female hyphae

12. Sexual Spores
a) Ascospores
b) Basidiospores
c) Zygospores
d) Oospores

13. a) Ascospores
• Single celled spores in sac like Ascus
(Asci)
• 8 Ascospores in each ascus
• Antheridium and Ascogonium of two
mating types fuse to form
Ascogenous hyphae, followed by
Crozier formation
• The tip of the crozier then fuses with
the penultimate cell and walls itself off
from the ascus
• Ascus – karyogamy – meiosis - 4
Haploid cells-Mitosos- 8 cells
• Eg: S.cerevisiae, Morels, Neurospora
crassa

14. b) Basidiospores
Nuclear
Fusion
Meiosis
Vacuole
Sterigma
Basidiospores
Basidium
• 4 haploid single celled spores on each
Basidium
• Basidium –Club shaped structure formed by
fusion of gametangia of two mating types
• Nuclear fusion and meiosis takes place in
the Basidium to form 4 haploid nuclei
• Basidiospores are produced exogenously at
the tips of special outgrowths called
Sterigma (Pl. Sterigmata)
• Sometimes, mitosis follows meiosis and 8
spores can be seen
• Eg: Mushrooms, Puff balls, Bracket fungi
(inedible mushrooms)

15. c) Zygospores
 Large thick walled resting spores formed
when tips of two sexually compatible
hyphae fuse together
 Zygospores are diploid structures formed
by the nuclear fusion of haploid cells
 Zygospore remains dormant in adverse
environmental conditions
 When the environment is favorable, the
zygospore germinates, meiosis occurs,
and haploid vegetative cells are released
 Eg: Rhizopus, Mucor

16. d) Oospores  Formed by gamete –gametangial
copulation
 Formed within special female
structure “Oogonium”
 One or more “Oospheres” in each
oogonium
 Fertiliztion of Oospheres by male
nucleus that migrate through
fertilization tube or pore into
female gametangium
 Eg: Saprolegnia

17.  Asexual & sexual spores may be surrounded by highly organized protective structures
called Fruiting bodies
 Sexual fruiting bodies- Perithecium and Apothecium
 Asexual fruiting bodies- Acervulus and Pycnidium
Fungal Fruiting bodies