Different modes of reproduction of fungi and reproductive structure and nutrition.pptx
1. A Presentation on
DIFFERENT MODES OF REPRODUCTION OF
FUNGI AND REPRODUCTIVE STRUCTURE
AND NUTRITION
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Presented By
Aliza Yesmin Begum
Roll No.2021/MSB/0065
4th Semester
Guided By
Prof.
Assistant Professor
Department of Botany
USTM, Meghalaya
3. INTRODUCTION
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A fungus is a eukaryotic organisms that includes micro-organisms such as
yeasts and mold as well as the more familiar mushroom.
Fungus are heterotrophs, they acquire their food by absorbing dissolved
molecules typically by secreting digestive enzyme into their environment.
Reproduction: It is the process by which plant and animals give rise to
offsprings.
It maintain or ensure the continuity of the species, germination after
germination.
Reproduction in Fungi can occur by:
(i) Vegetative Reproduction
(ii) Asexual Reproduction
(iii)Sexual Reroduction
4. VEGETATIVE REPRODUCTION IN FUNGI
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Vegetative reproduction is any form of reproduction occurring in plants in which a new plant
grows from a fragment of the parent plant or a specialized reproductive structure, the following
method are-Fission,Budding,Fragmentation,Sclerotia.
Fission: Some single-celled fungi, reproduce by
simple cell division, or fission, in which one cell
undergoes nuclear division and splits into
two daughter cells.
Some yeasts multiply by fission or division of
parent cell into equal halves and each half forms a
new individuals.
Pr0cess of Fission: In binary fission a mature
cell elongates and its nucleus divides into two
nuclei.
• The daughter nuclei separates, cleaves cytoplasm
centripetally in the middle till it divides parent into
two daughter protoplasm.
• A double cross wall is deposited in the middle to
form two daughtercell.
• Examples: Saccharomyces , Psygosaccharomyces
5. Budding: It is another method of vegetative reproduction, occurs in most yeasts
and in some filamentous fungi. In this process, a bud develops on the surface of either
the yeast cell or the hypha, with the cytoplasm of the bud being continuous with that
of the parent cell.
Often the buds are produced in a chain called as Promycelium.
Process of budding:
• Thecell wall bulgeout and softens in thearea probably by certain enzymes brought by
vesicles.
• The protoplasm also bulgeout in this region as small protuberance.
• The parent nucleus also divides into two, one of the daughter nucleus migrates into
bud, the cytoplasm of bud and mother remain continuous for some time
• As the bud enlarges, a septum is laid down at the joining of bud with mother cell.
Then bud separates and leads independent life.
• Some time, bud starts reproducing while still attached with mother cell. This gives
branching appearance.
• Budding is the typical reproductivecharacteristics of Ascomycetes.
• Examples: Yeast
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6. Fragmentation:
It occur in mycelial fungi .If the thallus is
broken up into smaller fragment either by
accidently or through use of external
forces,each small mycelial fragment grown
into a new individuals.
In the laboratory,
commonly propagated on a
fungi are
layer of solid
nutrient agar inoculated either with spores or
with fragmentsof mycelium.
Examples: Mushrooms.
Sclerotia:
The sclerotia are resistant and penetrating bodies.
Each sclerotium is cushion-like structure of compact
mycelium. They give rise to new mycelia on the
approach of favourableconditions.
Fragmentation
Sclerotia
7. ASEXUAL REPRODUCTION IN FUNGI
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Asexual reproduction occurred by formation of spores, A spore is a small
specialized uni and multicellular reproductive unit of dispersal that grows
into a new individuals like the parent after liberation. The following spores
are-
Sporangiospore , Oidia, Chalamydospores, Conidia
The spores are of diverse type and borne upon special structures called the
sporophores. These spores are produced asexually and called the asexual
spores.
Usually the spores are uninucleate and nonmotile but multinucleate and
motile spores are also
found.
The fungus producing more than one type of spores is called the pleomorphic
orpolymorphic.
The spores produced inside the sporangia are termed the endogenous spores
and the spores developing exogenously on the terminal ends of sporophores
arecalled theexogenous spores.
8. Some Examples of Asexual Spores
Sporangiospore: Theseasexual spore are produced in a sac like structure called
sporangia.
• Sporangium are produced at theend of special aerial hyphae called sporangiophore.
• Sporangium contains large numbers of haploid spores, which are released by rapture
of sporangial wall. Examples: Rhizopus
Oidia: These are the spore like hyphal segments in several fungi hypha divides by
transverse wall into a numbers of component cells or Oidium.
Chlamydospore: These are usually formed during unfavorable condition and are
thick walled singlecelled spore, which are highlyresistant to adversecondition.
• Hyphal cell or portion of hyphae contracts, loose water, round up and develops into
thick walled chalmydospore.
• When favorable condition returns, each chlamydospore give rise to a new
individual fungi. Examples: ascomycetes, basidiomycetes, zygomycetes, Histoplasma
capsulatum.
Conidia: The conidia are produced exogenously. They are non –motile spores extruded
singly or in chains from the tips of special hyphal branches called Conidiophores or
Conidia. Example: Penicillium, Apergillus
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10. Sexual Reproduction: It involves the formation and fusion of
gametes. Sexual reproduction found in all groups of fungi
except deuteromycetes or fungi imperfecti. Sexual
reproduction has three distinct phases i.e.
1. Plasmogamy (protoplasmic fusion): The process is the fusion
between two protoplasts of either gametes or cells to be
together the haploid nuclei of opposite mating type for their
ultimate union.
2. Karyogamy (fusion of nuclei): It is the fusion of two
compatible nuclei into one diploid nucleus.
3. Meiosis : Reduction division of zygote.
SEXUAL REPRODUCTION IN FUNGI
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11. Some Examples of Sexual Spores
Ascospore:
• It is usually singlecelled produced in a saccalled ascus (plural;asci) and usually thereare 4-8
ascospore in an ascus but the number mayvary from species tospecies
• The ascospore are usually arranged in a linearorder. In somecase ascospores are long, narrow
and arearranged in parallel order.
Basidiospore:
• It is a reproductive spore produced by basidiomycetes.
• This singlecelled spores are born in aclub shaped structure called basidium
• These basidiospore aervesas main airdispersal unit for the fungi.
Zygospore:
• Zygospores are thick walled spores formed when two sexuallycompatible hyphae orgametangia
of certain fungi fuse together.
• In suitablecondition, zygosporegerminates to produce a singlevertical hyphae which forms a
aporangium and releases its spores
Oospore:
• Theseare formed within a special female structure called Oogonium.
• Fertilization of egg by malegamete in female sex organ giverise tooospoes.
• Thereareone or moreoospores in each oogonium.
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12. EXAMPLES OF SEXUAL SPORES IN FUNGI
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Ascospores Basidiospores
Oospores
Zygospores
13. NUTRITION
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Fungi obtain their food by absorbing organic compounds
from their surroundings. Basis of their nutrition, they are
clasified as:
Saprotrophic Fungi: Fungi obtain food from dead and
decayed materials. Example: Aspergillus.
Parasitic Fungi: Get feed from living Organisms and
destroy them. Example: Puccinia.
Symbiotic Fungi: Grow in a living Organism and get
mutually benefited. Example: Lichen.
14. CONCLUSION
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The majority of Fungi are capable of both asexual
and sexual reproduction, which enable them to adapt
into the changing environmental circumstances.
Fungi have the ability to transform nutrients in a way
that makes them available for plants. Some fungi are
decomposers which mean that they break down
plant and animal debris, thus cycling nutrient and
increasing their availability in the soil.
15. https://www.britannica.com/science/fungus/Reproductive-processes-of-fungi
https://www.onlinebiologynotes.com/reproduction-in-fungi-asexual-and-sexual-methods/
https://www.yourarticlelibrary.com/fungi/reproduction-in-fungi-vegetative-asexual-and-
sexual-methods/7296
Vashistha BR and Sinha AK (2010) Botany for degree students: Fungi. S. Chand & company
limited, Ram nagar, New Delhi.
Webster J and Weber R. W. S. (2007) Introduction to fungi (3rd edition). Cambridge University
Press, New York.
Willey JM, Sherwood LM, Woolverton CJ (2017) Prescott’s Microbiology (10th Ed). McGraw-Hill
Education, 2 Penn Plaza, New York, NY 10121. ISBN 978-1-259-28159-4
Text book on Fungi by Ram Krushna Kar and Nihar Manjari Misra.
Studies in Botany (Vol I) by D. Mitra , J. Guha and S. K. Choudhuri.
BIBLIOGRAPHY
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