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Definitions. Mycologists --scientists who study fungi Mycology- -scientific discipline dealing with fungi Mycoses --diseases caused in animals by fungi . What is a fungus? .

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Definitions

Definitions

  • Mycologists--scientists who study fungi

  • Mycology--scientific discipline dealing with fungi

  • Mycoses--diseases caused in animals by fungi


What is a fungus

What is a fungus?

  • A eukaryotic, heterotrophic organism devoid of chlorophyll that obtains its nutrients by absorption, and reproduces by spores.

  • The primary carbohydrate storage product of fungi is glycogen.

  • Most fungi have a thallus composed of hyphae (sing. hypha) that elongate by tip growth


Definitions

  • The fungal thallus consists of hyphae; a mass of hyphae is a mycelium.


Structure of fungi

Structure of fungi


The characteristics of fungi

The Characteristics of Fungi

  • Fungi are NOT plants

  • Hyphae = tubular units of construction

  • Heterotrophic by absorption

  • Reproduce by spores

  • Ecologically pivotal roles


Hyphae

Tubular

Hard wall of chitin

Cross walls may form compartments (± cells)

Multinucleate

Grow at tips

Hyphae


Heterotrophic by absorption

Heterotrophic by Absorption

  • Fungi get carbon from organic sources

  • Hyphal tips release enzymes

  • Enzymatic breakdown of substrate

  • Products diffuse back into hyphae

Enzymatic breakdown

Nucleus hangs back

and “directs”

Products

Enzymes

Product diffuses back

into hypha and is used


Modifications of hyphae

Modifications of hyphae


Hyphal growth

Hyphal growth

  • Hyphae grow from their tips

  • Mycelium = extensive, feeding web of hyphae

  • Mycelia are the ecologically active bodies of fungi

This wall is rigid

Only the tip wall is plastic and stretches


Hyphal growth from spore

Hyphal growth from spore

germinating

spore

mycelium


Reproduce by spores

Reproduce by spores

  • Spores are reproductive cells

    • Sexual

    • Asexual

  • Formed:

    • Directly on hyphae

    • Inside sporangia

    • Fruiting bodies

Pilobolus sporangia

Penicillium hyphae

Amanita fruiting body


Fungi are ancient

Fungi are ancient

  • Major fungal lineages are ancient, perhaps emerging one billion years ago

  • Fungi were present before the emergence of animals and vascular plants


Old and modern classification

Old and Modern Classification

  • Carl Linnaeus (1707-1778) the “Father of Taxonomy”

    • “ Minerals exist; plants exist and live; animals exist, live and sense.”

    • Plants without obvious sexual organs were classified in Class Cryptogamia (lichens, fungi, mosses, ferns)

  • Fungi are primitive (asli) plants under this classification of organisms.


Definitions

Old Classification

The Five kingdom system

  • Eukarya (includes all organism with a nucleus & membrane bound organelles)

  • Plants and Animals are fairly obvious (ketara)

  • Fungi, are very distinct (berlainan) from the other kingdoms

  • Kingdom Protista is a “dumping ground” for organisms that don’t fit into the other eukaryotic kingdoms

    (Whittaker, 1969)


Modern classification

Modern Classification

  • At least 7 kingdoms are now recognized:

    • Eubacteria, Archaebacteria, Animalia, Plantae, Eumycota, Stramenopila (Chromista), Protoctista (Protozoa, Protista)


Systems of classifying fungi

Systems of classifying fungi

1) 1860

HOGG proposed the term PROTOCTISTA - fungi and neither

Plant or Animal.

This kingdom composed mostly of unicellular organisms.

The kingdom was later replaced by 2 kingdoms – MYCOTA &

MONERA (prokaryotes) and PROTOCTISTA(eukaryotes).

2) 1947

Microscopes enable study of complex structural characteristics.

New classification (WOLF & WOLF, 1947)

3) 1969

Fungi in its own kingdom by WHITTAKER – FUNGI KINGDOM.


Systems of classifying fungi1

Systems of classifying fungi

4) 1998

Modification by MARGUILIS & SCHWARTZ – used characteristics

(structure & function).

  • MONERA: Prokaryotes – bacteria, actinomycetes, blue-green algae.

  • PROTOCTISTA: Eukaryotes – protozoa and other unicellular and colonial organisms such as water moulds, slime moulds and slime nets.

  • FUNGI : Eukaryotes – organisms that lack flagella that develop from spores such as yeast, molds, rusts and mushrooms.

  • PLANTAE: Eukaryotes – organisms that develop from embryos such as liverworts, mosses and vascular plants.

  • ANIMALIA: Eukaryotes – organisms that develop from a blastula (hollow ball of cells) such a sponges, worms, arthropods and mammals.


Marguilis schwartz 1998

MARGUILIS & SCHWARTZ(1998)

Classify the fungi into 3 phyla : Zygomycota, Ascomycota and Basidiomycota.

Chytrids (CHYTRIDIOMYCOTA) in the Kingdom Proctista.

Deuteromycota with their closest relatives that are the Ascomycota and Basidiomycota.

Lichen with the Phylum Ascomycota.


Other classifications

Other classifications

MOORE, 1998 (quoted from Pfieffer, M., et al., 2001) states that plants, animals and fungi can be separated based on how they obtain energy.

Plants possess (memiliki) chloroplasts as photosynthetic structures used to produce food.

Animals possess mitochondria used for internalized digestion.

Fungi excrete enzymes into the food source they live within external digestion.


Classification using molecular research techniques

Classification using molecular research techniques

BALDAUF & PALMER (1993), WAINWRIGHT et al. (1993) and HASEGAWA et al (1993)

The above current schemes agree that the

three major kingdoms are separated and

thereby confirmed that there are no

connection between the fungi-plant

kingdom.


Definitions

KINGDOM

CHARACTERISTIC

EXAMPLE

Monera

Prokaryocyte

Bacteria

Actinomyces

Protista

Eukaryocyte

Protozoa

Eukaryocyte *

Fungi

Fungi

Plants

Eukaryocyte

Plants

Moss

Animals

Eukaryocyte *

Arthropods

Mammals

Man


Question 2

Question 2

Fill in the blanks of the systematic of classification

1) Kingdom

2) Division / Phylum

3) ___________

4) Order

5) ___________

6) Tribe

7) ___________

8) Species

  • Sometimes there are subdivisions and subclasses


Definitions

Hierarchical Classification

Kingdom Fungi

Phylum Basidiomycota

Class Basidiomycetes

Order Agaricales

Family Agaricaceae

Genus Agaricus

Species:

Agaricus campestris L.


F ungus versus f ungi

Fungus versus Fungi

  • “Fungus” is used inclusively for a heterogenous group of organisms that have traditionally been studied by mycologists

  • “Fungi” refers to the organisms in the Kingdom Fungi, the true fungi, also called the “Eumycota”


How are fungi named

How are fungi named?

  • To determine the correct name for a taxon, certain steps must be followed, including:

    • Effective publication

    • Valid publication

      • Description or diagnosis in Latin

      • Clear indication of rank

      • Designated type


Nomenclature

Nomenclature

  • Nomenclature: the “allocation (pemberian bahagian) of scientific names to the units a systematist considers to merit formal recognition.” (Hawksworth et al., 1995. The Dictionary of the Fungi). 

  • The nomenclature of fungi is governed by the International Code for Botanical Nomenclature, as adopted by the International Botanical Congress.


How many species of fungi exist

How many species of fungi exist?

- 80,000 species of fungi described

- 1,700 new species described each year


How many species of fungi exist1

How many species of fungi exist?

- 80,000 species of fungi described

- 1,700 new species described each year


Reasons why it is not easy to classify fungi

Reasons why it is not easy to classify fungi

Fungi comprise (mengandungi) of a broad number of organisms.

Fungi have various forms depending on the environment and conditions in which they grow.

Many terms being used to describe the morphological structures of fungi.


Definitions

Basic Characteristics and Life Cycles

  • Ascomycota (inc.Deuteromycetes)

  • Basidiomycota

  • Zygomycota

  • Mitosporic Fungi (Fungi Imperfecti)


Ascomycota sac fungi

Ascomycota – “sac fungi”

  • Teleomorphic fungi

    • Produce sexual and asexual spores

  • Sex. – asci

  • Asex. – common

  • Cup fungi, morels, truffles

  • Important plant parasites & saprobes

  • Yeast - Saccharomyces

  • Septate

  • Most lichens

A cluster of asci with spores inside


Basidiomycota club fungi

Basidiomycota – “club fungi”

  • Produce basidiospores and sometimes conidiospores

  • Sex – basidia

  • Asex – not so common

  • Long-lived dikaryotic mycelia

  • Rusts & smuts – primitive plant parasites

  • Septate

  • Mushrooms, polypores, puffballs

  • Enzymes decompose wood

  • Mycorrhizas

SEM of basidia and spores


Zygomycota zygote fungi

Zygomycota – “zygote fungi”

  • Conjugation fungi

  • Coenocytic

  • Sex - zygosporangia

  • Asex - common

  • Produce sporangiospores and zygospores

  • Hyphae have no cross walls

  • Grow rapidly

    • Rhizopus, Mucor (opportunistic, systemic mycoses)

  • Mycorrhizas

Fig 31.6 Rhizopus on strawberries


True fungi

True Fungi

  • Chytridiomycota – “chytrids”- Classified in CMR as true fungi (because of their molecular relationships)

  • Simple fungi

  • Produce motile spores

  • Mostly saprobes and parasites in aquatic habitats

  • Could just as well be Protists

Fig 31.5 Chytridium growing on spores


Definitions

True Fungi versus Slime Moulds

True fungi:

  • those that are hyphal

  • possess cell walls throughout most of their life cycle

  • are exclusively absorptive in their nutrition.

    Slime moulds:

    - those that do not form hyphae

    - lack cell walls during the phase that they obtain

    nutrients and grow

  • are capable of ingesting nutrients by phagocytosis. So they are more common to Protista although they produce fruiting bodies like fungi.

  • The most studied of them are the cellular slime moulds and theplasmodialslime moulds or Myxomycetes.


Question

QUESTION

The fungus can never be classified in

Plantae or Animalia?

EXPLAIN WHY?

(Hint ! LOOK AT ITS MOBILITY & NUTRITION)


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