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1. INTRODUCTION TO MYCOLOGY
BY
Dr P B MALLIKHARJUNA
GFGC YB
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2. Mycology – A General Account
Introduction: Mycology is a branch of Botany that deals
with the study of fungi.
 Fungi are the microscopic/macroscopic, achlorophyllous,
uni/multicellular, eukaryotic, heterotrophic, thalloid , non-
flowering plants / living organisms.
 The term ‘Mykos’ is derived from the Greek, which means
‘mushroom’ and “logos” means discourse.
 Alaxopoulos (1952) defined fungi as “the nucleated spore
bearing, achlorophyllous, eukaryotic, heteromorphic and non-
flowering plants/organisms”
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3.  Fungi are one of the largest group of living organisms
possessing about 5100 genera and 120,000 species
today
 However, the estimated fungi is approximately 1.5
million (15lakh) fungal species and every year the
mycologists discovering about 1700 new fungal
species.
 These are generally referred as the molds, yeasts,
toad stools, mushrooms, polypores, puffballs, rusts
and smuts.
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4.  Some of the known fungal genera are Aspergillus,
Mucor, Rhizopus, Aspergillus, Penicillium,
Saccharomyces, Albugo, Peziza, Puccinia,
Cercospora, Alternaria, Helminthosporium, Rhizoctonia,
Pyricularia, Colletotrichum, Agaricus, Chaetomium,
Phoma, Ustilago, Curvularia, Fusarium, Microsporum,
Candida, Neurospora, Claviceps, Sphacelotheca, Erwinia
, Phytophthora, Pythium, and so on .
 Micheli is the Father of Mycology & Anton von deBary
(1850) is the Founder of Modern Mycology and the
Father of Plant Pathology.
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5. IMPORTANT CHARACTERS OF FUNGI:
 Fungi are cosmopolitan in distribution, occurs in mostly
terrestrial; some are aquatic and some are air borne.
 Some fungi infects plants, animals and also human beings.
 The plant body is a thallus consisting of branched and
filamentous hyphae known as mycelium.
 Cell wall contains chitin (N- Acetyl glucosamine)
 Fungi are devoid of chlorophyll, so they are heterotrophic in
nutrition
 Reserve food materials are mainly glycogen or oil.
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6.  They may be parasites: obtaining nutrition from other
living plants or animals. Ex : Albugo, Puccinia
 Some fungi are saprophytes: obtaining nutrition from
dead and decaying organic matter, Ex :Mucor
 They reproduces by vegetative , asexual and sexual methods
 Vegetative reproduction takes place by fragmentation by
fission/budding.
 Asexual reproduction takes place by spores
 Sexual reproduction occurs in all groups of fungi except in
Deuteromycetes.
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7. THALLUS STRUCTURE:
 In fungi plant body is thallus. There is no chlorophyll in the thallus, so they
need a heterotrophic mode of nutrition
 The nature of thallus in fungi may be of three types viz,
1. Unicellular thallus
2. Multicellular thallus and
3. Mycelial thallus
 Unicellular thallus consists of single cell ,this is simple and primitive type
of thalli as in Yeast , slime molds and members of chytritids.
 Mycelial thallus consists of microscopic filaments. Each filament is a
linear row of cells joined end to end.
 The highly branched filamentous thallus is known as mycelium. Individual
branch of mycelium is called a hypha.
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8.  Hyphae may or may not
have cross walls, the
cross walls are called
septa.
 The hyphae with septa
is called septate.Each
septum is pierced by a
pore called septal pore
or central pore.
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10. MYCELIUM: The fungal body usually consists of mass of
hyphae called mycelium. It may be intercellular or intracellular
in the host.
 COENOCYTIC MYCELIUM: In this, the mycelium is usually
tubular, siphon-like without cross septa. Further, it is multi-
nucleate, highly branched and usually found in the primitive
fungi. Ex. Albugo.
 SEPTATE MYCELIUM: it is a major type that occurs in advanced
fungi. Here the fungus is filamentous , multicellular, and highly
branched. The mycelium may be monokaryotic or dikaryotic.
The cross septa may be simple or dolipore in nature.
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11. Fungal mycelia have the following modifications,
1. Plectonema 2. Sclerotia 3. Sporophores/ condiophores , 4 .Stroma &
5. Rhizomorph
1.Plectenchyma : is a compactly interwoven mass of hyphae,
here individual hyphae are partly fused and partly unfused but
close to each other.
2.Pseudoparenchyma: Some times individual hyphae are
compactly fused to each other and appears as parenchymatous
tissue this compact portion.
3.Prosenchyma :Less compact structures consisting of hyphae
made of elongated cells called prosenchyma.
4.Both pseudoparenchyma and prosenchyma mostly formed during
formation of fruiting bodies of Ascomycetes and Basidiomycetes.
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13. 2. Sclerotia: It consists of a
compact mass of interwoven
hyphae forming pseudo
parenchyma. The outer hyphae
become hard and form a
protective covering or rind. These
bodies remain dormant under
unfavorable conditions and
germinate at the onset of
favorable conditions.
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14. 3. Sporophores: A part of
mycelium that bears spores
on it called sporophore.The
sporophore may be
branched or unbranched and
it may either produce
sporoangiospore or
conidiospores.
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15. 4. Stroma: is a cushion like structure formed by
pseudoparenchymatous fungal tissue. The sporophore
usually arises from the Stroma. It is formed at the later
stages of development of mycelium.
5. Rhizomorph: is a rope like coiled structure formed by
intervening of fungal hyphae. It looks like a small rope and
dark brown in colour. These are formed during favourable
conditions. The rhizomorph produces new mycelium.
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16. FUNGAL CELL STRUCTURE
• Eukaryotic – 1/ many nucleated, Monoploid(Haploid)
(Single set of chromosomes)
• Cell wall – Chitin and Fungal cellulose.
• Plasma membrane with ergo sterols
• Presence of Small nucleus, Mitochondria, ER, Golgi
complex, vesicles, 80S ribosomes and vacuoles,
• The chief reserve food is glycogen and oil.
• Lomasomes – presence of the plasma membrane outward
foldings and vesicles collectively referred as Lomasome
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17. Yeast cell- ultrastructure
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18. FUNGAL GROWTH
• Fungal cells will undergo the mitotic cell division in order
to grow both vegetatively and reproductively.
• Apical growth is present in mycelial fungi.
• The growth is very rapid in fungi. For instance, an
individual fungus may produce more than a kilometer of
new hyphae within a day.
• The growth rate is depending both on the availability of
CN-rich nutrients and also the external factors like
darkness, low temperature, slightly acidic pH and high
relative humidity.
• Both Phytochrome and Cryptochrome involve in the fungal
growth and morphogenesis.
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19. NUTRITION IN FUNGI
• As the fungi are achlorophyllous, they obtain nutrition
by the heterotrophic method. There are three
methods,
1.Saprophytic mode of nutrition
2.Parasitic mode of nutrition
3.Symbiotic mode of nutrition
• Further, the mode of digestion is both extracellular &
intra-cellular. The uptake of nutrients is by the
absorption.
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20. 1.Saprophytic nutrition:
• Majority of fungi obtain its nutrition from the dead and
decaying organic matter called Saprophytes or
Saprobes.
• Saprophytes are two types: obligate saprophytes and
facultative saprobes.
• Fungi which live on dead organic matter and incapable of
infecting living organisms are called obligate saprobes.
• Fungi which usually live on living host and occasionally
they live on dead organic matter as well are called
facultative saprobes.
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21. • Some of the saprophytic fungi are;
• Coprophilous fungi : grow on cattle
waste Ex. Chaetomium and Pilobolus
species
• Keratinophilous fungi : grow on
keratin rich decaying substances like hair
and nails. Ex. Microsporum gypseum ,
and Trichophyton terrestre.
• Lignicolous Fungi:that not only grow
on wood but permeate its fibrous
structure and actually cause decay, Ex.
Armillaria and Brown rot, soft rot &
White rot fungi.
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22. 2.Parasitic nutrition:
• Fungi live on other organisms and obtain their nutrition from
a living host.
• These are classified into obligate parasites and facultative
parasites
• Obligate parasites live only on living organisms (Albugo)
• Where as facultative parasites live in dead and decaying
organic matter and/or on living organisms. (Armillaria)
• They usually draw the nutrients from the host by the
haustoria.
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23. 3. Symbiotic nutrition: some fungi live in close association
with roots or stems of certain higher plants and that
fungi/plant get some mutual benefits. This type of nutrition is
called symbiosis. Ex: Lichens and Mycorrhizae.
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24. 4. Predacious fungi: Certain fungi
living in the soil traps the eel worms
and nematodes by making rings of
hyphae around them. These rings
capture nematodes and produce
haustoria into the nematodes. By
these haustoria into the nematodes
fungi absorbs nutrients from the
nematodes. These fungi are called
predacious fungi or Nematophagous
fungi.
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25. REPRODUCTION IN FUNGI
 Holocarpic fungi : Fungi like in unicellular fungi
(Synchitrium , Saccharomyces ) the entire vegetative cell is
transformed into a reproductive unit.
 Eucarpic fungi : In majority of mycelial fungi( Pythium ,
Penicillium , Helminthosporium), only a part of vegetative
body forms reproductive unit and rest portion remains as
vegetative.(Albugo, Peziza, Puccinia)
 Fungi reproduces by three means ,
1. Vegetative
2. Asexual and
3. Sexual methods
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26. 1. Vegetative reproduction: takes place by the following methods,
I. Fragmentation: common in filamentous fungi (Rhizopus , Alternaria ,
Fusarium) where the hyphae breakdown into two or more fragments
due to some external force and each one develop into a new
individual.
II.Budding: takes place in unicellular fungi (yeast). A small outgrowth
i.e., the bud emerges out from parent cell. Nucleus divides into two
and one passes to the bud. The bud is then separated by partition
wall, but continues its growth. Later it breaks off and grow
individually.
III.Fission: normally unicellular fungi reproduces by this method,
where the vegetative cell elongates and divides into two daughter
cells of equal size by simple constriction in the middle with
simultaneous nuclear division.
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27. Asexual reproduction
• This is the predominant type of reproduction in fungi.
• Takes place by means of several types of spores, generally
produced during the favourable conditions.
• The main objective is to increase its population and thereby
occupying different habitats.
• The spores may be unicellular or multicellular. They may be
exogenous or endogenous in development.
• Some of the spores are Zoospores, Condiospores,
Chlamydospores, Oidospores, Sporangiospores, etc.
• Some times, they may also develop into the asexual fruiting
bodies like Coremia, Synnemata, Sporodochia and Acervuli.
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28. Fruiting bodies
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29. 1. Zoospores: zoospores may be uni
or biflagellate, generally pear shaped
produced in sporangium.
Ex:Synchytrium & Saprolegnia
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30. 2. Conidia: these are exogenously produced; non-motile
spores developed by the constriction at the end of specialized
hyphal branches called conidiophores. They may be
single(Pythium) or in chain(Penicillium). These are the
dominant type of asexual spores.
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A WIDE RANGE OF CONIDIA

32. 3. Oidia :in some fungi, the
hyphal tips often divide by
transverse wall into large
number of small segments
which may remain in chain or
becomes free from each other.
These are known as oidia. Ex.
Lichens
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33. 4. Chlamydospores : These are
thick walled, round to oval in
outline, brown or black in
coloured spores, produced
either terminally or intercalary
at some intervals through out
the length of hyphae, during
unfavourable conditions Ex:
Fusarium
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34. 5. Sporangiospores : these are
globose, multinucleate , non-
motile aplanospores formed inside
sporangium. The sporoangiospore
germinates by producing germ
tube. Later, it develops into a
profusely branched mycelium.
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35. 3. Sexual reproduction
 Involves the union of male and female gametes or two
gametangia.
 Occurs during unfavourable conditions.
 Involves gametogenesis followed by the fertilization.
 A large number of fungi reproduce by sexual means but
deuteromycetes lacks sexual reproduction.
 The general types of sexual reproduction are as follows
I. Planogametic copulation
II. Gametangial contact
III.Gametangial copulation
IV. Spermatogamy &
V. Somatogamy
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36. I. Planogametic copulation: planogametes are motile
flagellate gametes.
• It is the union of motile male and female gametes
• It is of following types, a. Isogamy b. Anisogamy
c. Oogamy
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37. II. Gametangial contact :
• Gametangia are the sex organs.
• Oogonium is the female sex organ
and Antheridium is the male sex
organ
• Two gametangia of opposite sex
come in contact , the content of
the male antheridium migrates
into female gametangia.
• Karyogamy and Plasomgamy ->
Oospore.
• Ex. Albugo
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38. III. Gametangial copulation: The reproductive
structures are involved in the fusion. The entire content of
two contacting gametangia fuses and process the diploid
structure called Zygospore. Ex. Mucor
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39. IV. Spermatogamy : Here a small
male sperm is formed and pollinated
onto the female gametangia.
• Spermatium is the male sex organ
and
• The Receptive is the female sex
organ
• More common in the Ascomycetous
and Basidiomycetous fungi.
Ex. Puccinia
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40. V. Somatogamy : in some
higher fungi belongs to the
classes Ascomycetes and
Basidiomycetes, the sex
organs are not produced.
• Here the somatic hyphae
directly involves in sexual
fusion.
• This fusion is based on the
homothallic and heterothallic
condition.
• Ex. Peziza
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41. Sexual Fruiting Bodies of Fungi
ASCOMYCTES
FUNGI
BASIDIOMYCETES
FUNGI
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42. Role of Fungi
• Decomposers (saprophytes)
• Soil clump formation
• Improves soil fertility as Bio fertilizers
• Produce Mycotoxins/ Antibiotics/Industrial products
• Cause Plant diseases (5000 Fungi)
• Cause Human and animal diseases (175 fungi)
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43. CLASSIFICATION OF FUNGI
• Several mycologists proposed different types of classification based
on the charecters of fungi
• How ever, Ainsworth classification and Alexapoulous classification are
adopted by many.
 The classification of fungi is based primarily on the characteristics of
the sexual spores and fruiting bodies present during the sexual
stages of their life cycles.
 However, the complete or perfect life cycles of many fungi are yet to
known.
 Ainsworth (1973) classified fungi primarily based on the nature of
thallus and more importantly on the type of spores produce during
reproduction.
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44. Albugo Penicillium Puccinia
AINSWORTH CLASSIFICATION
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 The Kingdom Fungi is divided into two
Divisions and 9 Classes.
 1. Division – Myxomocota and
 2. Division – Eumycota

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possess slime molds with amoeboidal thallus
due to lack of cell wall; holocarpic and coenocytic.
 It has four Classes viz., 1. Acrasiomycetes, 2. Hydromyxomycetes,
3. Myxomycetes and 4. Plasmodiophoromycetes.
 Class 1 - Acraciomycetes includes the cellular slime molds with
free living assimilatory phase forming pseudoplasmodium. Ex.
Dictyostelium
 The Class 2- Hydromyxomycetes includes the netlike molds .
Ex. Labyrinthula
 The Class 3- Myxomycetes include the true slime molds with
saprophytic plasmodium. Ex. Physarum
 Class 4. Plasmodiophoromycetes include the endo-parasitic
slime molds. Ex. Plasmodiophora

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 Divission II :Eumycota are the true fungi with
chitinous cell wall, and with either unicellular or
multicellular filamentous mycelial thallus.
 Based on the spore bearing structures, in which the
spores are produced, these are classified into 5 sub-
divisions namely,
 Sub-division I: Mastigomycotina
 Sub-division II: Zygomycotina
 Sub- division III : Ascomycotina
 Sub- division IV: Basidiomycotina
 Sub- division V: Deuteromycotina

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Sub-division I: Mastigomycotina:
 Aseptate and coenocytic mycelial fungi
 The motile – flagellate zoospores are produced in the
asexual reproduction.
 Sexual reproduction is the gametangial contact.
 Ex. Albugo, Phytophthora
Sub-division II: Zygomycotina :
 Aseptate and coenocytic mycelial fungi
 Asexual reproduction is by the formation of non-motile
spores inside the sporangium
 Sexual reproduction is the gametangial copulation and
the resultant Zygospore, is a resting spore.
 Ex. Mucor, Rhizopus

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 Sub-division III: Ascomycotina (Sac fungi)
 A sac like structure called ascus produces or bears sexual spores
called ascospores.
 Sexual reproduction occurs by single celled or multi-celled conidia.
 Unicellular or mycelial fungi
 Hyphae are generally septate.
 Examples: Saccharomyces, Peziza, Aspergillus, Penicillium.
Sub-division IV: Basidiomycotina (Club fungi)
 Sexual spores called basidiospores are produced externally on a
club shaped basidia
 Asexual reproduction occurs by budding, fragmentation or conidia
formation
 They are commonly called as mushroom group.
 Hyphae are generally septate.
 Examples: Amanita, Agaricus, Puccinia

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Sub-division V: Deuteromycotina (Imperfect fungi)
 These fungi are also known as fungi imperfectii.
 No sexual stage is present or not known
 Asexual reproduction occurs by means of conidia.
 Septate mycelial fungi
 Examples: Cercospora, Colletotrichum,

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References and Suggested Further Reading:
 1. Text Book of Fungi : BR Vashishsta et al . S Chand
Publications, 2016.
• 2. An Introduction to Fungi: HC Dube, Scientific Publishers
, 2012.
 3. Introduction to Fungi : Webster & Weber, Cambridge
University Press, 2007