Fungi is a group of nucleated (eukaryotic), an achlorophyllous organism that reproduces by both sexual and asexual methods.
· Mycology or Mycetology is the study of fungi.
· Father of mycology – P. Micheli.
· Father of modern mycology: Anton de Barry (a german botanist: Also father of plant pathology).
Similarities of Fungi with Algae
· Both are eukaryotic· In both the plant body is thallose I;e no differentiation into root, stem and leaves.
· Both are non-vascular i.e xylem and phloem are absent,
· In both sex organs are unicellular and non-jacketed.
· No embryo formation in the life cycle.
· Asexual reproduction occurs by mitospores.
Difference between Fungi and Algae:
| Algae | Fungi |
|---|---|
| 1. Chlorophyll is present. | 1. Absent i.e acholorophyllous |
| 2. Autotrophic nutrition | 2. Heterotrophic nutrition |
| 3. Cell wall is made up of cellulose | 3. Cell wall is made up of chitin or fungal cellulose. |
| 4. Reserve food material is starch. | 4. Glycogen or oil globules is reserve food material (no starch) |
| 5. True parenchyma is present which is formed by cell division. | 5. Pseudoparenchyma is present, which is formed by interwoven mycelium. |
| 6. As we move from lower forms to higher forms(Myxophyceae to Rhodophyceae) there is a progressive elaboration of sex organs or sexual reproduction. | 6. As we move from lower to higher form (Phycomycetes to dueteromycetes) there is a reduction in sexuality and in Duteromycetes; sexual reproduction is completely absent and hence known as imperfect fungi or fungi imperfecti. |
· Earlier in the 2 kingdom system fungi was kept in the division Thallophyta. Now, in 5 kingdom systems, fungi or mycota is the separate kingdom.
· Fungi are heterotropic and ubiquitous organisms where the nutrition is absorptive type.
· They are multicultural decomposers
· Their size ranges from one-celled yeast to multicellular large toadstools.
· Toadstools are poisonous mushrooms.
· Rigid cell wall made up of Chitin – a nitrogenous polysaccharide except for oomycetes which have a cellulose cell wall.
· Stored food material is in the form of glycogen.
· Most of them are moisture-loving and terrestrial, but few are Aquaticeg; Monoblepharis and Saprolegnia and these are commonly called water moulds.
Note: Saprolegnia is present in dead flies in the water.
· Lomasomes (border bodies) are the globular outgrowth of cell membrane which helps in cell wall synthesis.
· Ribosome not bound to ER but freely found in the cytoplasm.
· The dictyosomes are unicisternal.
· Fungi are heterotrophic thallophytes.
· Body of fungi is in the form of a fine thread-like tubular branched structure called hyphae (singular: hypha). The entire mass of hyphae is called mycelium. It is a haploid.
· Plectenchyma: Hypha may be loosely or compactly arranged.
· Prosenchyma: loosely interwoven mass in which hyphae are easily distinguishable from one another.
· Pseudoparenchyma: Hyphae are compactly packed, have lost their individuality.
Fungi are:
· Holocarpic – whole body involves in reproduction.· Eucarpic – only a part of the thallus is involved in reproduction.
· Nutrition in fungi is ‘absorptive type’ and absorptive structure is haustoria. Digestion takes place outside the body (extracellular).
· Saprophytic – obtained food from decayed matter e.g. Mucor
a. Obligate saprophyte– true saprophyte.
b. Facultative saprophyte –Actually parasite but they can also live as a saprophyte. Eg; Alternaria solani, Fusarium solani.
c. Parasitic– They live in the body of the host.
Also, Parasites that cause disease are called pathogens.
i. Obligate parasite – True parasite.
ii. Facultative parasites – They are actually saprophytes but they can be also live as parasites. Eg: Rhizopus
Symbiotic:
· Lichen – Symbiotic association between algae and fungi.
· Mycorrhiza – symbiotic association between the roots of higher plants and fungi. The fungus helps in the uptake of minerals (mainly phosphorus).
· In adverse conditions, mycorrhiza acts as root hair.
· It may be ectotrophic eg; pinus or endotrophic eg; orchids.
· In ectomycorrhiza, the fungus is usually basidiomycetes.
· In endomycorrhiza, the fungus is usually zygomycetes.
· In endomycorrhiza, tips of fungal hyphae pass into cortical cells producing swollen vesicles or finely branched masses called arbuscles which is also called VAM (Vesicular Arbuscular Mycorrhiza)
NOTE: Rhizoctonia is a common fungus associated with the roots of orchids.
· Endophytic fungi – fungi growing inside the body of the host.
· Fungi grow well at 20-30 degrees centigrade and at acidic ph(6)
· Plant body of fungi is represented by mycelium (plural = mycelia) which is made up of a net mass of tubular filaments called hyphae(singular hypha).
· The hypha is usually branched, tube-like structure, having Protoplasm with reserve food and bounded by a wall of chitin, a nitrogenous polysaccharide.
· Hyphae show apical growth.
· Definite cell wall is present in hyphae which are made up of chitin (a polymer of N-acetyl glucosamine, NAG) or fungal cellulose.
So, stained with cotton blue.
· By hyphae, the fungus develops a large surface, from which it can secrete digestive enzymes on food products which can then be easily absorbed by fungi.
· The hyphae may be aseptate (without cross-wall) and multinucleate (coenocytic), however in the reproductive phase, septa may be formed. eg; Rhizopus, Albugo, phytophthora etc or maybe septate (with transverse partition).
· In septate forms, each cell may be uninucleated (monokaryotic) or dikaryotic or with many nuclei.
· The nucleic undergo intranuclear spindle formation and Karyochrosis.
· The septum maybe with a simple pore or with Dolipore (Basidiomycetes)
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| Fig: Septum with simple pore |
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| Fig: Septum with dolipore spore. |
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| Fig: Mycelium of a fungus with septate hyphae. |
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| Fig: Mycelium of a fungus with aseptate (coenocytic) hyphae. |
· Some fungi which trap and kill nematodes, annelids, eelworms, etc in soil are called predaceous fungi.
· The fungi that grow on the wood are known as epixylic fungi.
· The fungi growing on nails, feathers hairs and hoofs are referred to as Keratenophilic.
The mycelium may form some peculiar structure in some fungi like:
1. Plectenchyma:
Mycelium of higher fungi is modified to form a loose or compact mass of tissue-like structure called plecetenchyma. It is of two types :
(a) Prosenchyma: when mycelium forms a wave in which hyphae are loosely woven, and are easily distinguishable.
(b) Pseudoparenchyma or paraplectenchyma: Hyphae are compactly arranged so not easily distinguishable.
2. Sclerotia:
When mycelium by interweaving forms a compact resting structure called the sclerotium.
3. Sometimes fungal mycelia (i.e hyphae ) are interwoven to form thick thread-like roots, which are known as rhizomorphs and they function like roots i.e help in absorption. Eg; in Agaricus.
When mycelium by interweaving forms a compact resting structure called the sclerotium.
3. Sometimes fungal mycelia (i.e hyphae ) are interwoven to form thick thread-like roots, which are known as rhizomorphs and they function like roots i.e help in absorption. Eg; in Agaricus.
4. Traps: In predatory fungi (Dactylella, Arthrabotrys, Dactylaria), hyphae forms loop and trap nematode, eelworm etc.
5. Haustoria: The intracellular hyphae in endoparasite form knob-like structures into host tissue called haustoria and help to absorb the food.
5. Haustoria: The intracellular hyphae in endoparasite form knob-like structures into host tissue called haustoria and help to absorb the food.
Reproduction in fungi:
1. Vegetative reproduction is by Budding or Fission e.g. yeast (budding)2. Asexual reproduction is by
a. Zoospore: Motile spores formed inside zoosporangium. e.g. Albugo.
b. Sporangiospores: Non-motile spores formed inside sporangium.
c. Chlamydospores: Thick-walled, single-celled highly resistant spores formed during unfavourable conditions. They are non-motile spores developed in a somatic hypha.
d. Oedia: These are non-motile spores formed under special conditions i.e.excess of sugar, water and certain salts.
e. Conidia: Non-motile spore formed at the tip of the hypha. They are borne singly or in chains. Conidia differ from sporangiospores as these are not produced inside sporangium.
3. SEXUAL REPRODUCTION
· Deuteromycetes (fungi imperfecti) lacks sexual reproduction.
· Aquatic fungi generally form motile gametes.
· In landform '+' and '-' strains are fused to form a thallus. Fusion occurs only in between dissimilar hypha. This Phenomenon is known as Heterothalism.
Sexual reproduction completes in three plates.
a. Plasmogamy: fusion of protoplasm.
b. Karyogany: fusion of nuclei.
c. Meiosis: Involves the reduction of chromosome to haploid.
a. Zoospore: Motile spores formed inside zoosporangium. e.g. Albugo.
b. Sporangiospores: Non-motile spores formed inside sporangium.
c. Chlamydospores: Thick-walled, single-celled highly resistant spores formed during unfavourable conditions. They are non-motile spores developed in a somatic hypha.
d. Oedia: These are non-motile spores formed under special conditions i.e.excess of sugar, water and certain salts.
e. Conidia: Non-motile spore formed at the tip of the hypha. They are borne singly or in chains. Conidia differ from sporangiospores as these are not produced inside sporangium.
3. SEXUAL REPRODUCTION
· Deuteromycetes (fungi imperfecti) lacks sexual reproduction.
· Aquatic fungi generally form motile gametes.
· In landform '+' and '-' strains are fused to form a thallus. Fusion occurs only in between dissimilar hypha. This Phenomenon is known as Heterothalism.
Sexual reproduction completes in three plates.
a. Plasmogamy: fusion of protoplasm.
b. Karyogany: fusion of nuclei.
c. Meiosis: Involves the reduction of chromosome to haploid.
Types:
Planogamatic copulation (fusion of naked gametes)
· It's the fusion of motile gametes i.e, one or both gametes are motile.
Gametangial contact: Male and female gametangia (structure containing gametes) comes close to each other and develops a fertilization tube through which male gametangium enters into the female gametangium.
E.g in oomycetes Albugo, pythium
Gametangial Copulation: Two Gametangia or their protoplasts are fuses and the zygote develops into arresting spore.
E.g. Rhizopus, Mucor (zygomycetes)
Somatogamy: Fusion of two vegetative cells.
e.g. Agaricus
Ascospores: Produced in Sac called an ascus which is endogenous in nature.
e.g. Ascomycetes (yeast)
Basidiospores: Produced in basidia, exogenous in nature.
Zygospores: Thick-walled spores produced by the fusion of entire gametangia.
Coprophillous fungi: Fungi growing on during.
Predaceous fungi: These fungi trap and kill the nematodes and annelids.
Epixylic fungi: These are those fungi that grow on wood.
Keratinophilic fungi: These fungi grow on nails, hairs and hoofs.
· All fungi are multicellular except yeast which is a unicellular fungus.
· Aseptate mycelium may be aseptate or septate. Aseptate mycelium is multinucleate and is called coenocytic. i.e. lower fungi (Phycomycetes).
Zygospores: Thick-walled spores produced by the fusion of entire gametangia.
Coprophillous fungi: Fungi growing on during.
Predaceous fungi: These fungi trap and kill the nematodes and annelids.
Epixylic fungi: These are those fungi that grow on wood.
Keratinophilic fungi: These fungi grow on nails, hairs and hoofs.
· All fungi are multicellular except yeast which is a unicellular fungus.
· Aseptate mycelium may be aseptate or septate. Aseptate mycelium is multinucleate and is called coenocytic. i.e. lower fungi (Phycomycetes).
Fungi grow in two-phase in their life cycle. Assimilatory or vegetative phase and reproductive phase.
A. Assimilative phase or vegetative phage – fungi grow within the substratum take food.
B. Reproductive phase: Mycelium grows aerially to produce sex organs and a fruiting body.
· Sex organs of fungi are called gametangia. Gametangia may be male (antheridium) or female (oogonium).
A. Assimilative phase or vegetative phage – fungi grow within the substratum take food.
B. Reproductive phase: Mycelium grows aerially to produce sex organs and a fruiting body.
· Sex organs of fungi are called gametangia. Gametangia may be male (antheridium) or female (oogonium).
Those fungi which exist in two forms i.e. yeast-like form and mould like form are called Dimorphic fungi. eg. Blastomyces.
Fruiting bodies are sexual spore-bearing structures in higher fungi.
Ascocarp: Fruiting body of Ascomycetes
Basidiocarp: Fruiting body of Basidiomycetes
Perithecium: Flask shaped and open like fruiting body found in Claviceps
Cleistothecium: Spherical and closed fruiting body eg. Aspergillus, penicillium.
Apothecium: Cup-shaped fruiting body eg. Peizza.
Ascocarp: Fruiting body of Ascomycetes
Basidiocarp: Fruiting body of Basidiomycetes
Perithecium: Flask shaped and open like fruiting body found in Claviceps
Cleistothecium: Spherical and closed fruiting body eg. Aspergillus, penicillium.
Apothecium: Cup-shaped fruiting body eg. Peizza.
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Fig: Different
kinds of sexual reproduction in Fungi. |
Classification of Fungi
1. MYXOMYCETES (Myxa = slime + mykes = fungus)Mycelium is coenocytic without a cell wall.
· They are often called slime moulds due to the presence of slime mass during vegetative reproduction.
· Plant body is naked, amoeboid, and multinucleate.
· Cell wall is absent so best material to study the protoplasm.
· Vegetative phase is the naked mass of protoplasm called pseudoplasmodium.
· No hyphae.
Eg: Synchytrium (causes the disease called wart disease).
2. PHYCOMYCETES (Algal fungi)
· Mycelium is coenocytic with the cell wall.
· Innumerable spores are produced in them endogenously in sporangium.
· These fungi are also called "Black mould"
2. PHYCOMYCETES (Algal fungi)
· Mycelium is coenocytic with the cell wall.
· Innumerable spores are produced in them endogenously in sporangium.
· These fungi are also called "Black mould"
a. Zygomycetes (conjugation fungi)
· Coenocytic mycelium
· Asexual reproduction by non-motile sporangiospores is called Aplanospores.
· Sexual reproduction by conjugation or gametangial copulation forming zygospore.
· Zygospore is formed as a result of sexual reproduction.
E.g. Pin mould (Mucor, Rhizopus)
b. Oomycetes (egg fungi)
· Sexual reproduction by gametangial contact and the product of sexual reproduction is oospore.
· Sexual reproduction by gametangial contact and the product of sexual reproduction is oospore.
· Also called zoosporic fungi or water fungi.
· Asexual reproduction by zoospore formation.
· They don't have a chitinous cell wall instead they have cellulosic cell walls.
· It is the only group of fungi that give rise to biflagellate zoospores.
· Asexual reproduction by zoospore formation.
· They don't have a chitinous cell wall instead they have cellulosic cell walls.
· It is the only group of fungi that give rise to biflagellate zoospores.
E.g. Phytophora, Albugo
Note: Albugo causes white rust of tea.
Note: Albugo causes white rust of tea.
c. Ascomycetes (Sac fungi)
· Mycelium is septate, hyphae are multinucleate.
· Presence of Ascospores which are endogenous in nature.
· No.of Ascus per ascospores is usually 8 and sometimes
· Fruiting body is Ascocarp.
· Presence of Ascospores which are endogenous in nature.
· No.of Ascus per ascospores is usually 8 and sometimes
· Fruiting body is Ascocarp.
· Conidiophores are unbranched in Aspergillus but branched in penicillium.
· Complete absence of motile cells.
· Asexual reproduction is usually by conidia and vegetative reproduction by budding.
· Sexual reproduction occurs by gametangial contact which gives rise to Ascus.
· Each ascus has 4-8 endogenously(generally 8) produced ascospores arranged either linearly(Neurospora) or unorderly (eg; yeast).
· Ascospores are sexual spores.
· The asci are grouped to form definite fruiting bodies called ascocarp.
· Ascocarp may be:
a. Apothecium: Cup-shaped.
b. Perithecium: flask-shaped
c. Cleistothecium: (Globose shaped, without opening)
· Crozier formation occurs in the formation of the ascus.
· Complete absence of motile cell.
Eg: Penicillium, Aspergillus, Neurospora, Yeast. (@PANY)
· Complete absence of motile cells.
· Asexual reproduction is usually by conidia and vegetative reproduction by budding.
· Sexual reproduction occurs by gametangial contact which gives rise to Ascus.
· Each ascus has 4-8 endogenously(generally 8) produced ascospores arranged either linearly(Neurospora) or unorderly (eg; yeast).
· Ascospores are sexual spores.
· The asci are grouped to form definite fruiting bodies called ascocarp.
· Ascocarp may be:
a. Apothecium: Cup-shaped.
b. Perithecium: flask-shaped
c. Cleistothecium: (Globose shaped, without opening)
· Crozier formation occurs in the formation of the ascus.
· Complete absence of motile cell.
Eg: Penicillium, Aspergillus, Neurospora, Yeast. (@PANY)
Neurospora (Pink mould/pink bread mould). It is also called Drosophila of the plant kingdom.
d. Basidiomycetes (Club fungi)
· Mycelium is septate and it is a group of most advanced fungi.
· Presence of Basidium and basidiocarp.
· Basidiospores are exogenous in nature.
· Clamp connections are a universal occurrence.
· Except in smuts and rusts, the septum is dolipore septum.
· Mycelium is septate and it is a group of most advanced fungi.
· Presence of Basidium and basidiocarp.
· Basidiospores are exogenous in nature.
· Clamp connections are a universal occurrence.
· Except in smuts and rusts, the septum is dolipore septum.
Mycelium is of two types:
a. Primary mycelium: formed by the germination of basidiospore and it is monokaryotic.
b. Secondary mycelium: formed by fusion of two primary mycelia. So, it is dikaryotic.
· Motile cells are absent.
· Sex organs are absent but all 3 phases of sexual reproduction namely plasmogamy, karyogamy, and meiosis are present.
· Basidium is the characteristics reproductive organ of basidiomycetes where both karyogamy and meiosis occurs.
· Typically basidium bears basidiospores.
· Basidiospores are sexual spores or meiospores.
· Basidiospores are exogenously produced on peg-like outgrowths called sterigmata.
· NO. of basidiospores per basidium is usually 4 but sometimes 2 as well.
· Fruiting body – Basidiocarp.
· In Puccinia (rust fungi) and Ustilago (smut fungi) basidiocarp and true basidia are absent.
· Hyphae septate and uninucleate separation is with dolipore separation and clamp connection.
a. Primary mycelium: formed by the germination of basidiospore and it is monokaryotic.
b. Secondary mycelium: formed by fusion of two primary mycelia. So, it is dikaryotic.
· Motile cells are absent.
· Sex organs are absent but all 3 phases of sexual reproduction namely plasmogamy, karyogamy, and meiosis are present.
· Basidium is the characteristics reproductive organ of basidiomycetes where both karyogamy and meiosis occurs.
· Typically basidium bears basidiospores.
· Basidiospores are sexual spores or meiospores.
· Basidiospores are exogenously produced on peg-like outgrowths called sterigmata.
· NO. of basidiospores per basidium is usually 4 but sometimes 2 as well.
· Fruiting body – Basidiocarp.
· In Puccinia (rust fungi) and Ustilago (smut fungi) basidiocarp and true basidia are absent.
· Hyphae septate and uninucleate separation is with dolipore separation and clamp connection.
E.g. Agaricus, Puccinia (causes rust disease in wheat), Ustilago (smut)
· Agaricus edible mushroom
· Amanita toadstools or poisonous mushroom
· Agaricus edible mushroom
· Amanita toadstools or poisonous mushroom
e. Deuteromycetes (Fungi imperfecti)
· Septed mycelium
· Asexual reproduction by conidia.
· This group of fungi is called fungi imperfect because sexual reproduction is absent.
· Hyphae is septate and uninucleate.
· Also called as form fungi.
E.g. Fusarium, Alternaria.
Note: Alternaria causes early blight of potato.
· Saprophytic fungi, mycelium is coenocytic (multinucleate) grows on moist fruit, decaying vegetables, wet-shoe animal dung and decaying organic media.
· Plant body is composed of a mass of white, delicate, cottony threads collectively known as mycelium which is coenocytic (multinucleate)
· It is coprophilous, i.e. it grows on horse dung and is also called dung mould.
· Some species of mucor can grow as facultative or secondary parasites on fruits, vegetables and internal organs of man and animals.
· Thallus of the fungus is called mycelium composed of filaments called hyphae.
· The hyphae are aseptate; 3 types viz prostrate, subterranean and aerial.
· Subterranean hyphae also called rhizoidal hyphae and aerial hyphae are called sporangiophores.
Reproduction:
Mucor multiplies by 3 methods:
1. Vegetative Reproduction: Takes place by fragmentation either mechanically or by decay.
Kingdom: Plantae
Subkingdom: Thallophyta
Division: Mycota
Subdivision: Eumycotina
Class: Ascomycetes
Subclass: Hemiascomycetidae
Order: Endomycetales
Family: Saccharomycetaceae
Genus: Saccharomyces (Yeast)
· Saprophytic fungi, unicellular so non-mycelia.
· Sometimes pseudo-mycelium during budding.
· Yeast is the smallest fungus
· Extensively used in Brewery and Baking.
· Commonly called Baker's yeast.
· Saccharomyces has the property of changing sugar into alcohol.
· Common species of yeast is called Saccharomyces cerevisiae Baker's yeast or Brewer's yeast.
· Unicellular eukaryotic organism and saprophytic in nature.
· Has a special property of changing sugar into alcohol and carbon dioxide by an enzyme called zymase This process is known as fermentation.
· Yeast prefer sugar-rich medium.
· Reproduction takes place by budding followed by fission.
· Sexual reproduction rarely occurs (conjugation)
· Repeated budding without separation may produce a structure called Pseudomycellium.
· Somatic (vegetative) cell of yeast may be haploid (n), diploid (2n)
· Fruiting body ascocarp.
· During unfavourable conditions yeast cell undergoes 2 nuclear divisions forming four nuclei.
· Each nucleus is surrounded by cytoplasm and cell wall which is called Ascospores.
· They can live anaerobically by fermentation so they are called facultative aerobe.
· Yeast produce an enzyme zymase which helps in fermentation.
· Yeast commonly reproduces by budding.
· Pseudomycellium (temporary association of hyphae) is found in yeast.
The sexual life cycle is three types:
1. Haplobiontic
· Haploid phase is dominant. E.g. Schizosaccharomyces octosporus.
2. Diplobiontic
· Diploid (2n) phase is dominant. E.g. Saccharomyces ludwigii.
3. Haplodiplobiontic (Haploid and diploid both). E.g. Saccharomyces cerevisiae.
Types of Ascocarps
There are four main types of Ascocarps (fruiting) body of ascocarp)
1. Cleistothecium (or cleistocarp) – A completely closed fruiting body with no special opening for the liberation of the ascospores.
2. Perithecium – flask-shaped fruiting body.
3. Apthecium – wide open, cup or saucer-shaped fruiting body.
4. Ascostroma – cushion-like structure due to loosely interwoven hypha.
· Yeast is the source of Riboflavin (Vitamin B2).
· Primary mycelium is formed by the germination of a basidiospore and is short-lived.
· Later primary mycelium becomes dikaryotic by hyphal fusion of somatogamy and results in secondary mycelium, which spreads through the substratum and persists for many years.
· Process of secondary mycelium formation is known as dikaryotisation.
· Group of secondary mycelium grow upward and form fruiting bodies i.e. Basidiocarp.
· Basidiocarp consists of stipe and pileus. Gills are found in pileus.
· Gill region contains Basidium where karyogamy and meiosis occur.
· Each basidium has finger-like projections called sterigmatas, single basidium bears 4 basidiospores each at the top of sterigmata.
· Somatogamy produces dikaryotic mycelium.
· Dikaryotic or 2° mycelium produces a pseudo-parenchymatous rounded button-like body (button stage), which forms reproductive/fruiting body (basidiocarp/sporocarp).
· Each gill has 3 zones of dikaryotic hyphae:
(i) Central zone made up of compactly arranged hyphae called Trama.
(ii) Subhymenium
(iii) Hymenium / thecium
· Edible mushroom – Agaricus campestris
· Poisonous forms – Amanita species.
· Poisonous mushrooms are also called toadstools which possess a cup-like structure called volva at the base.
Fairy rings are concentric rings found in the fruiting body or basidiocarp (fruiting body) of mushrooms.
· Species of Penicillium are the source of important antibiotics.
· Penicillin acts by inhibiting cell wall synthesis in bacteria.
· LSD (Lysergic acid diethylamide) a narcotic is obtained from ergot of fungus (Claviceps, Purpurea)
· Aspergillus is used in the cheese industry.
· Dermatophytosis or Ringworm disease in man is a fungal disease.
· Agaricus is a common edible mushroom.
· In the alcoholic industry, Yeast (saccharomyces) has the property of fermentation because of zymase Glucose Ethyl alcohol + CO2
Black rust of wheat: Puccinia.
2. Red tide is due to the dinoflagellate.
3. Histerophyta includes fungi.
4. Parasexuality was first discovered in Aspergillus nidulans by Pontecorvo and roper
6. Fruiting body: present in higher fungus as spore-bearing structure;
Ascocarp: In ascomycetes
Basidocarp: In basidiomycetes
Perithecium: Flask shaped (@peri-feri)
Cleistothecium: Closed fruiting body
Apothecium: Opened ascocarp
9. In Agaricus
1. Mycelium: uninucleated haploid
2. Mycelium: Binucleated haploid
3. Mycelium: uninucleated diploid
10. Parts of gills:
i. Trama: Central portion made up of an interwoven mass of elongated hyphae
ii. Subhymenium: Layer of the small round cells on either side of the trama.
iii. Hymenium: Outermost layer was club-shaped fertile basidia and sterile paraphysis.
Note: Alternaria causes early blight of potato.
Life Cycle
1. Mucor (Black mould or Pin mould or Bread mould)· Saprophytic fungi, mycelium is coenocytic (multinucleate) grows on moist fruit, decaying vegetables, wet-shoe animal dung and decaying organic media.
· Plant body is composed of a mass of white, delicate, cottony threads collectively known as mycelium which is coenocytic (multinucleate)
· It is coprophilous, i.e. it grows on horse dung and is also called dung mould.
· Some species of mucor can grow as facultative or secondary parasites on fruits, vegetables and internal organs of man and animals.
· Thallus of the fungus is called mycelium composed of filaments called hyphae.
· The hyphae are aseptate; 3 types viz prostrate, subterranean and aerial.
· Subterranean hyphae also called rhizoidal hyphae and aerial hyphae are called sporangiophores.
Reproduction:
Mucor multiplies by 3 methods:
1. Vegetative Reproduction: Takes place by fragmentation either mechanically or by decay.
2. Asexual Reproduction
Occur by any one of the following mitospores:
(a) Sporangiospores
· Formed under favourable conditions.
· Arise singly at the tip of erect usually unbranched hyphae called sporangiophores.
· Sterile structure of sporangium is called columella which helps in dispersion.
(b) Chlamydospores
(c) Gemma
(d) Oidia (= Oidospores = arthrospores = sprout cells)
· Oidia increases in number by budding. The budded state is also termed as Torula stage.
Occur by any one of the following mitospores:
(a) Sporangiospores
· Formed under favourable conditions.
· Arise singly at the tip of erect usually unbranched hyphae called sporangiophores.
· Sterile structure of sporangium is called columella which helps in dispersion.
(b) Chlamydospores
(c) Gemma
(d) Oidia (= Oidospores = arthrospores = sprout cells)
· Oidia increases in number by budding. The budded state is also termed as Torula stage.
3. Sexual reproduction:
· Sexual reproduction takes place in heterothallic species by conjugation (Gametangial copulation) of two similar gametes (isogametes).
· It results in the formation of diploid zygospore which germinates to give a new mycelium (promycelium).
· Heterothalism was 1st observed by Black Slee in 1904.
· Meiosis occurs during the formation of zygospores.
· Sometimes the conjugation fails to take place. Then the gametangia round off and get surrounded by a thick wall, resulting in the formation of haploid azygospore or parthenospores.
· The central sterile region of sporangium is called columella and it helps in the dispersal of spores.
· Sexual reproduction takes place in heterothallic species by conjugation (Gametangial copulation) of two similar gametes (isogametes).
· It results in the formation of diploid zygospore which germinates to give a new mycelium (promycelium).
· Heterothalism was 1st observed by Black Slee in 1904.
· Meiosis occurs during the formation of zygospores.
· Sometimes the conjugation fails to take place. Then the gametangia round off and get surrounded by a thick wall, resulting in the formation of haploid azygospore or parthenospores.
· The central sterile region of sporangium is called columella and it helps in the dispersal of spores.
Common Name of some common fungi:
- Mucor: Pin mould
- Rhizopus: Black mould
- Penicillium: Blue-green mould
- Aspergillus: Blue mould
- Neurospora: Pink mould or pink bread mould.
- Saccharomyces: Budding yeast
- Agaricus: Mushroom.
- Penicillium: Green mould/Blue mould
- Saprolegnia: Water mould
 |
| Fig: Showing Life cycle of Mucor |
Difference Between Rhizopus and Mucor
Rhizopus |
Mucor |
|---|---|
| Commonly grows on bread, hence called bread mould. | Commonly grows on dung (coprophilous) |
| Mycelium is differentiated into 3 types of hyphae; rhizoidal, stoloniferous, sporangiophore | Mycelium is undifferentiated i.e, only one type of hypha is present. |
| Sporangiophore arises in a tuft of 3-5 from one node. | Sporangiophore arises singly. |
| Meiosis occurs during the germination of the zygospore after the resting period. | Meiosis occurs soon after karyogamy before the resting period of the Zygospore. |
2. Yeast (Saccharomyces)
Systematic position:Kingdom: Plantae
Subkingdom: Thallophyta
Division: Mycota
Subdivision: Eumycotina
Class: Ascomycetes
Subclass: Hemiascomycetidae
Order: Endomycetales
Family: Saccharomycetaceae
Genus: Saccharomyces (Yeast)
· Saprophytic fungi, unicellular so non-mycelia.
· Sometimes pseudo-mycelium during budding.
· Yeast is the smallest fungus
· Extensively used in Brewery and Baking.
· Commonly called Baker's yeast.
· Saccharomyces has the property of changing sugar into alcohol.
· Common species of yeast is called Saccharomyces cerevisiae Baker's yeast or Brewer's yeast.
· Unicellular eukaryotic organism and saprophytic in nature.
· Has a special property of changing sugar into alcohol and carbon dioxide by an enzyme called zymase This process is known as fermentation.
· Yeast prefer sugar-rich medium.
· Reproduction takes place by budding followed by fission.
· Sexual reproduction rarely occurs (conjugation)
· Repeated budding without separation may produce a structure called Pseudomycellium.
· Somatic (vegetative) cell of yeast may be haploid (n), diploid (2n)
· Fruiting body ascocarp.
· During unfavourable conditions yeast cell undergoes 2 nuclear divisions forming four nuclei.
· Each nucleus is surrounded by cytoplasm and cell wall which is called Ascospores.
· They can live anaerobically by fermentation so they are called facultative aerobe.
· Yeast produce an enzyme zymase which helps in fermentation.
· Yeast commonly reproduces by budding.
· Pseudomycellium (temporary association of hyphae) is found in yeast.
The sexual life cycle is three types:
1. Haplobiontic
· Haploid phase is dominant. E.g. Schizosaccharomyces octosporus.
2. Diplobiontic
· Diploid (2n) phase is dominant. E.g. Saccharomyces ludwigii.
Types of Ascocarps
There are four main types of Ascocarps (fruiting) body of ascocarp)
1. Cleistothecium (or cleistocarp) – A completely closed fruiting body with no special opening for the liberation of the ascospores.
2. Perithecium – flask-shaped fruiting body.
3. Apthecium – wide open, cup or saucer-shaped fruiting body.
4. Ascostroma – cushion-like structure due to loosely interwoven hypha.
· Yeast is the source of Riboflavin (Vitamin B2).
3. Penicillium (Blue-Green mould)
· Ascomycetes fungi
· Penicillium is commonly called blue or green mould is a very common and widely distributed fungus growing in bread, vegetables, fruits, jams, etc.
· The famous antibiotic penicillin was first produced from the species Penicillium notatum by Sir Alexander Fleming in 1929.
· Branched conidiophores are found in Penicillium.
· Ascomycetes fungi
· Penicillium is commonly called blue or green mould is a very common and widely distributed fungus growing in bread, vegetables, fruits, jams, etc.
· The famous antibiotic penicillin was first produced from the species Penicillium notatum by Sir Alexander Fleming in 1929.
· Branched conidiophores are found in Penicillium.
4. Claviceps:
· Ascomycetes fungi
· Causes ergot of Rye which contains mind-altering chemicals related to drug LSD that causes hallucinations.
· Ascomycetes fungi
· Causes ergot of Rye which contains mind-altering chemicals related to drug LSD that causes hallucinations.
5. Agaricus (Mushroom)
Systematic position
Kingdom: Plantae
Subkingdom: Tallophyta
Division: Mycota
Subdivision: Eumycotina
Class: Basidiomycetes
Subclass: Homobasidiomycetidae
Series: Hymenomycetes
Order: Agaricales
Family: Agaricaceae
Genus: Agaricus
· Saprophytic in nature.
· Vegetative plant body is mycelium which is found inside the soil.
· Hyphae is septate with dolipore septum and clamp connection. Hyphae are uninucleate.
· 3 types of mycelia are involved in the life cycle of mushrooms. They are
(i) Primary mycelium: Uninucleate and diploid
(ii) Secondary mycelium: Binucleate (Dikaryotic) and haploid
(iii) Tertiary mycelium: Uninucleate & diploid
Systematic position
Kingdom: Plantae
Subkingdom: Tallophyta
Division: Mycota
Subdivision: Eumycotina
Class: Basidiomycetes
Subclass: Homobasidiomycetidae
Series: Hymenomycetes
Order: Agaricales
Family: Agaricaceae
Genus: Agaricus
 |
Fig: Different
parts of Mushroom |
· Also called club fungi, Gill fungi and Fairy ring.
 |
Fig: Fairy rings
(Ring of fruiting bodies) |
· Saprophytic in nature.
· Vegetative plant body is mycelium which is found inside the soil.
· Hyphae is septate with dolipore septum and clamp connection. Hyphae are uninucleate.
· 3 types of mycelia are involved in the life cycle of mushrooms. They are
(i) Primary mycelium: Uninucleate and diploid
(ii) Secondary mycelium: Binucleate (Dikaryotic) and haploid
(iii) Tertiary mycelium: Uninucleate & diploid
· Primary mycelium is formed by the germination of a basidiospore and is short-lived.
· Later primary mycelium becomes dikaryotic by hyphal fusion of somatogamy and results in secondary mycelium, which spreads through the substratum and persists for many years.
· Process of secondary mycelium formation is known as dikaryotisation.
· Group of secondary mycelium grow upward and form fruiting bodies i.e. Basidiocarp.
· Basidiocarp consists of stipe and pileus. Gills are found in pileus.
· Gill region contains Basidium where karyogamy and meiosis occur.
· Each basidium has finger-like projections called sterigmatas, single basidium bears 4 basidiospores each at the top of sterigmata.
Reproduction:
· Vegetative reproduction takes place by fragmentation.
· Asexual reproduction by Chlamydospore.
· Sexual reproduction:
· Somatogamy; without sex organs.
· Somatogamy results in the formation of dikaryotic mycelium which develops fruiting the body or basidiocarp.
· Central region of the gill is called as trama
· On the side of the trama there is a layer of small rounded cells called as sub-hymenium and the outermost layer of the gill is hymenium (fertile layer)
· In this layer(hymenium), there are aseptate, club-shaped fertile cells called basidia and sterile paraphyses intermixed with basidia.
· Each basidium develops four sterigmata with a basidiospore at the top of each.
· On germination, each basidiospore forms primary mycelium.
· Vegetative reproduction takes place by fragmentation.
· Asexual reproduction by Chlamydospore.
· Sexual reproduction:
· Somatogamy; without sex organs.
· Somatogamy results in the formation of dikaryotic mycelium which develops fruiting the body or basidiocarp.
· Central region of the gill is called as trama
· On the side of the trama there is a layer of small rounded cells called as sub-hymenium and the outermost layer of the gill is hymenium (fertile layer)
· In this layer(hymenium), there are aseptate, club-shaped fertile cells called basidia and sterile paraphyses intermixed with basidia.
· Each basidium develops four sterigmata with a basidiospore at the top of each.
· On germination, each basidiospore forms primary mycelium.
 |
| Fig: Mature basidiocarp showing Gills |
 |
| Fig: Sexual reproduction in Agaricus |
 |
| Fig: Showing different parts of fungal gills |
· Somatogamy produces dikaryotic mycelium.
· Dikaryotic or 2° mycelium produces a pseudo-parenchymatous rounded button-like body (button stage), which forms reproductive/fruiting body (basidiocarp/sporocarp).
· Each gill has 3 zones of dikaryotic hyphae:
(i) Central zone made up of compactly arranged hyphae called Trama.
(ii) Subhymenium
(iii) Hymenium / thecium
· Edible mushroom – Agaricus campestris
· Poisonous forms – Amanita species.
· Poisonous mushrooms are also called toadstools which possess a cup-like structure called volva at the base.
Fairy rings are concentric rings found in the fruiting body or basidiocarp (fruiting body) of mushrooms.
Uses of Fungi
· Yeast is the source of Riboflavin (Vit. B2) and it is widely used in Brewery and Baking industries.· Species of Penicillium are the source of important antibiotics.
· Penicillin acts by inhibiting cell wall synthesis in bacteria.
· LSD (Lysergic acid diethylamide) a narcotic is obtained from ergot of fungus (Claviceps, Purpurea)
· Aspergillus is used in the cheese industry.
· Dermatophytosis or Ringworm disease in man is a fungal disease.
· Agaricus is a common edible mushroom.
· In the alcoholic industry, Yeast (saccharomyces) has the property of fermentation because of zymase Glucose Ethyl alcohol + CO2
Some Diseases caused by Fungi:
| Plant disease | Causal fungi |
|---|---|
| Late blight of potato | Phytophthora infestans |
| White rust of crucifers | Albugo candida puccinia |
| Ergot of Rye Red rot of sugar | Claviceps purpures Colletorichum |
| Early blight of potato or Tomato | Alternaria |
Black rust of wheat: Puccinia.
Note: Human disease
1. Athlete's food by Tenea pedi
2. Meningitis by Cryptococcus neoformns
3. Ringworm by Trichophyton, Microsporum
4. Aspergillosis (lung disease) by Aspergillus fungimatus
5. Otomycosis (Otomycosis) by Aspergillus
2. Meningitis by Cryptococcus neoformns
3. Ringworm by Trichophyton, Microsporum
4. Aspergillosis (lung disease) by Aspergillus fungimatus
5. Otomycosis (Otomycosis) by Aspergillus
· Fungi as a source of food
i. Agaricus-Mushroom (Basidiomycetes)
ii. Morchella-Morel (Ascomycetes)
iii. Mushroom is nutritious in nature due to the presence of protein (20-30%), Vit (B, C, D) and minerals
i. Agaricus-Mushroom (Basidiomycetes)
ii. Morchella-Morel (Ascomycetes)
iii. Mushroom is nutritious in nature due to the presence of protein (20-30%), Vit (B, C, D) and minerals
· Fungi as medicine
i. Penicillin antibiotics
ii. Ergoten
iii. Ephedrin
iv. Clavicin- an anticancerous substance obtained from Clavatia, so eaten to prevent stomach cancer.
v. Flavicin
vi. Camapestrin
vii. Griseoflavin
· Role of fungi in industries
i. In the alcohol industry: Yeast in fermentation due to zymogen enzyme.
ii. Enzymes: Used in retting fibres, curing tobacco disease.
· Invertase: S. cerevisiae
· Zymase: S. cerevisiae
· α-amylase: Aspergillus oryzae.
· Protease: A. flavus
iii. Organic acid:
· Citric acid: Aspergillus niger
· Oxalic acid: Aspergillus niger
· Gluconic acid: Aspergillus niger
· Fumaric acid: Rhizopus stolonifer
· Fungi in phytohormones
· Fungi as poison
· Hallucinogenic fungi
i. Penicillin antibiotics
ii. Ergoten
iii. Ephedrin
iv. Clavicin- an anticancerous substance obtained from Clavatia, so eaten to prevent stomach cancer.
v. Flavicin
vi. Camapestrin
vii. Griseoflavin
· Role of fungi in industries
i. In the alcohol industry: Yeast in fermentation due to zymogen enzyme.
ii. Enzymes: Used in retting fibres, curing tobacco disease.
· Invertase: S. cerevisiae
· Zymase: S. cerevisiae
· α-amylase: Aspergillus oryzae.
· Protease: A. flavus
iii. Organic acid:
· Citric acid: Aspergillus niger
· Oxalic acid: Aspergillus niger
· Gluconic acid: Aspergillus niger
· Fumaric acid: Rhizopus stolonifer
· Fungi in phytohormones
· Fungi as poison
· Hallucinogenic fungi
High Yielding Points from Fungi
1. Aspergillus is also called a guinea pig of the plant kingdom (@ g=g)2. Red tide is due to the dinoflagellate.
3. Histerophyta includes fungi.
4. Parasexuality was first discovered in Aspergillus nidulans by Pontecorvo and roper
5. Classes of fungi:
a. Phycomycetes:
i. Zygomycetes: Rhizopus and mucor
ii. Albugo, Pythium
b. Ascomycetes: e.g.: Penicillin, Aspergillus, Neurospora, Yeast (@ PANY)
c. Basidiomycetes: Amanita, Agaricus, @2A
d. Deuromycetes: Fusarium, Alternaria (Alternaria causes early blight of potato)
e. Myxomycetes: A/k Slim moulds e.g.: Synchytrium
a. Phycomycetes:
i. Zygomycetes: Rhizopus and mucor
ii. Albugo, Pythium
b. Ascomycetes: e.g.: Penicillin, Aspergillus, Neurospora, Yeast (@ PANY)
c. Basidiomycetes: Amanita, Agaricus, @2A
d. Deuromycetes: Fusarium, Alternaria (Alternaria causes early blight of potato)
e. Myxomycetes: A/k Slim moulds e.g.: Synchytrium
6. Fruiting body: present in higher fungus as spore-bearing structure;
Ascocarp: In ascomycetes
Basidocarp: In basidiomycetes
Perithecium: Flask shaped (@peri-feri)
Cleistothecium: Closed fruiting body
Apothecium: Opened ascocarp
7. Penicillin: Blue-green mould
Neurospora: Pink mould (@ Drosophila of the plant kingdom)
Neurospora: Pink mould (@ Drosophila of the plant kingdom)
8. In yeast:
i. Pseudomycelium is present
ii. Life cycle may be:
a. Haplontic: eg; Schizosaccharomyces octosporus
b. Diplobiontic: Sacchromyces ludwigi (@ d = d = d)
c. Haplodiplobiontic: Saccharomyces cerevisae
i. Pseudomycelium is present
ii. Life cycle may be:
a. Haplontic: eg; Schizosaccharomyces octosporus
b. Diplobiontic: Sacchromyces ludwigi (@ d = d = d)
c. Haplodiplobiontic: Saccharomyces cerevisae
9. In Agaricus
1. Mycelium: uninucleated haploid
2. Mycelium: Binucleated haploid
3. Mycelium: uninucleated diploid
10. Parts of gills:
i. Trama: Central portion made up of an interwoven mass of elongated hyphae
ii. Subhymenium: Layer of the small round cells on either side of the trama.
iii. Hymenium: Outermost layer was club-shaped fertile basidia and sterile paraphysis.
Also, Read Notes of Other Lessons of Botany: