Reproductive structure of fungi
Reproduction:
Reproduction is the process of producing new individual possessing all the characteristics typical to species.
In case of fungi, there are two types of reproduction occurs generally-
Ø Sexual reproduction and
Ø Asexual reproduction.
Sexual reproduction:
The process of sexual reproduction typically consists of three distinct phases, viz
v Plasmogamy
v Karyogamy and
v Meiosis.
Plasmogamy brings two n haploid nuclei together in one cell. Karyogamy units them into one diploid zygote nucleus and meiosis restores the haploid condition in the four nuclei that result from it.
Plasmogamy (Gr. plasma = a molded object & gamos = marriage/ union):
The union of two protoplasts brings the nuclei close together within the same cell. It is the first phase of the sexual reproduction.
Karyogamy (Gr. karyon = nut, nucleus & gamos = marriage):
The fusion of two nuclei which are brought together by plasmogamy is called karyogamy. It constitutes the second phase of the sexual reproduction. Karyogamy follows plasmogamy almost immediately in many of the simplier fungi. In the more complex fungi, however these two processes are separated in time and space
Spore:
The word spore comes from the Greek word spore which means spore or seed. A spore is a minute progative unit funtioning as seed but different from seed in that spore doesn’t contain a performed embryo. Either it may be unicellular or a number of cells which are cut off and dispersed as a whole joined together. Color of spores varies from hyaline through green, orange, red, yellow,
Types of spores:
Either the spore born in sporangia (called sporangiospores) or produced at tips or side (called conidia) of hyphae in various. Viz,
Motile(Pjbkxj) sporangiospore/ Zoospore and
Non motile sporangiospore/ Aplnospore.
Plasmogamy (Gr. plasma = a molded object & gamos = marriage/ union):
The union of two protoplasts brings the nuclei close together within the same cell. It is the first phase of the sexual reproduction.
Karyogamy (Gr. karyon = nut, nucleus & gamos = marriage):
The fusion of two nuclei which are brought together by plasmogamy is called karyogamy. It constitutes the second phase of the sexual reproduction. Karyogamy follows plasmogamy almost immediately in many of the simplier fungi. In the more complex fungi, however these two processes are separated in time and space
Spore:
The word spore comes from the Greek word spore which means spore or seed. A spore is a minute progative unit funtioning as seed but different from seed in that spore doesn’t contain a performed embryo. Either it may be unicellular or a number of cells which are cut off and dispersed as a whole joined together. Color of spores varies from hyaline through green, orange, red, yellow,
Types of spores:
Either the spore born in sporangia (called sporangiospores) or produced at tips or side (called conidia) of hyphae in various. Viz,
Motile(Pjbkxj) sporangiospore/ Zoospore and
Non motile sporangiospore/ Aplnospore.
Motile sporangisporre:
In similar fungi, this is known as zoospores and equipped with one or two flagella. There are two types of flagella have found in motile sporangiospore. i.e.
a) Whiplash type: Which is divided into two parts? Upper part is short and flexible but lower part is longer.
b) Tinsel type: It has a feathery structure consisting of rachis with lateral hair like projections on all sides called mastigonemes or filmers.
Non motile sporangiospore:
It is also know as aplanospores and it is not moving.
Sporangium:
These are sac like structure. It entire contents are converted through cleavage into one or more spores, usually many. Shape and size of sporangium varies widely flaked shape to cylindrical, irregular loped, club shape, elongate or globose in form. The spores produce in sporangium is known as sporangiospores. Sporangiosspores escape through babillae. Through a pore on sporangial wall or at end of a discharge tube. This escape ness occurred by an apical opening formed by an apical opening formed by separation of a minute tip (Lid).
In similar fungi, this is known as zoospores and equipped with one or two flagella. There are two types of flagella have found in motile sporangiospore. i.e.
a) Whiplash type: Which is divided into two parts? Upper part is short and flexible but lower part is longer.
b) Tinsel type: It has a feathery structure consisting of rachis with lateral hair like projections on all sides called mastigonemes or filmers.
Non motile sporangiospore:
It is also know as aplanospores and it is not moving.
Sporangium:
These are sac like structure. It entire contents are converted through cleavage into one or more spores, usually many. Shape and size of sporangium varies widely flaked shape to cylindrical, irregular loped, club shape, elongate or globose in form. The spores produce in sporangium is known as sporangiospores. Sporangiosspores escape through babillae. Through a pore on sporangial wall or at end of a discharge tube. This escape ness occurred by an apical opening formed by an apical opening formed by separation of a minute tip (Lid).
Conidia:
In deuteromycetes spores are produced on conidia. It produced non motile spores formed at tip and side of sporangeous cells of fungal hyphae. Shapes of conidia varies as spherical, ovoid, star shaped, cylindrical, elongated, thread like, spirally curved etc.
Pycnidia:
In deuteromycetes conidia are produced on flask shaped flattened or round fruits called or round fruits called pycnidia. The inner walls of pycnidia have conidiophrous which is cut off into uni or multicelluler spores. The mouth of pycnidia called ‘ostile’. The wall of pycnidia called ‘peridium’.
Sporophores:
These are one type of fruiting body having specialized branches or tissues from thallus. The brances bears spores, sporangium and conidium.
In deuteromycetes spores are produced on conidia. It produced non motile spores formed at tip and side of sporangeous cells of fungal hyphae. Shapes of conidia varies as spherical, ovoid, star shaped, cylindrical, elongated, thread like, spirally curved etc.
Pycnidia:
In deuteromycetes conidia are produced on flask shaped flattened or round fruits called or round fruits called pycnidia. The inner walls of pycnidia have conidiophrous which is cut off into uni or multicelluler spores. The mouth of pycnidia called ‘ostile’. The wall of pycnidia called ‘peridium’.
Sporophores:
These are one type of fruiting body having specialized branches or tissues from thallus. The brances bears spores, sporangium and conidium.
Acervulus:
These are also one type of fruiting body which have saucer shaped. In its exposed surface there are depressed mass of aggregated hyphae bearing conidiophores which grows side by side.
Sporodochium:
These is the another fruiting body similar to acervulus. It forms as cushion (Mw`) like aggregation of hyphae which breaks through the host surface and conidiophores.
These are also one type of fruiting body which have saucer shaped. In its exposed surface there are depressed mass of aggregated hyphae bearing conidiophores which grows side by side.
Sporodochium:
These is the another fruiting body similar to acervulus. It forms as cushion (Mw`) like aggregation of hyphae which breaks through the host surface and conidiophores.
Sorus (pl.Sori):
When spores and sporophores grouped into masses or clustersin the fungal hyphae then its called sorus.
When spores and sporophores grouped into masses or clustersin the fungal hyphae then its called sorus.
Ascus (pl.Asci):
In ascomycetes spores are enclosed in a mother sac which is called ascus. Asci are enclosed in a complex fruit called ascocarp. Ascocarp is three types –
o Cleistothecium
o Perithecium and
o Apothecium.
In ascomycetes spores are enclosed in a mother sac which is called ascus. Asci are enclosed in a complex fruit called ascocarp. Ascocarp is three types –
o Cleistothecium
o Perithecium and
o Apothecium.
Cleistothecium
The asci are produced inside a completely closed ascocarp in some ascomycetes. These ascocarps are known as cleistothecium. This ascocarp is globe shaped no ostile present. It is covered with hyphal growth.
Perithecium:
The ascocarp which is more or less closed but at maturity it is provided with a pore trough which asci/spores escape. This ascocarp look likes pycnidium but in it instead of conidia, there are asci develop from vessels mass of cell.
The asci are produced inside a completely closed ascocarp in some ascomycetes. These ascocarps are known as cleistothecium. This ascocarp is globe shaped no ostile present. It is covered with hyphal growth.
Perithecium:
The ascocarp which is more or less closed but at maturity it is provided with a pore trough which asci/spores escape. This ascocarp look likes pycnidium but in it instead of conidia, there are asci develop from vessels mass of cell.
Apothecium:
The ascocarp that produced their asci in parallel/series on exposed surface (flat, convex or concave) is known as apothecium. The layer bearing asci is called hymenium. The asci are always facing upward bcoz of gaining moisture for dispersal. It is disc like or cup like.
The ascocarp that produced their asci in parallel/series on exposed surface (flat, convex or concave) is known as apothecium. The layer bearing asci is called hymenium. The asci are always facing upward bcoz of gaining moisture for dispersal. It is disc like or cup like.
Dispersal of fungi
Dispersal of fungi:
Spores – capacity to etain germinative power flora long
time. e.g. rust fungi.
In dispersal incidence:
In dispersal incidence 3 stages present-
· Take off
o Active release and
o Passive release.
· Transport/ Flight
· Deposition/ Landing
Active release:
By structural mechanism. e.g. hygroscopic movement.
By physiological movement. e.g.
Passive release:
External situation/ Condition are responsible. E.g. Strong air,
rain drop, insects etc.
Dispersal of fungi:
Spores – capacity to etain germinative power flora long
time. e.g. rust fungi.
In dispersal incidence:
In dispersal incidence 3 stages present-
· Take off
o Active release and
o Passive release.
· Transport/ Flight
· Deposition/ Landing
Active release:
By structural mechanism. e.g. hygroscopic movement.
By physiological movement. e.g.
Passive release:
External situation/ Condition are responsible. E.g. Strong air,
rain drop, insects etc.
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