recent classification of fungi

1. Classification of
Fungi
Assist. Professor
mycologist
Dr. Asia Saadullah

2. Major criteria used in the classification
and phylogeny of fungi
1-Morphology
2. Anatomical Characters
3. Nutrition and Physiology
4. Chemistry of Low-Molecular-Weight
Compounds
5. Carbohydrates and Cell Wall Composition
6. Molecular Methods

3. Fungi are more closely related to animals
than plants…
•Like animal cells, fungal cells have plate-like
cristae in their mitochondria.
•Because fungi are more chemically and
genetically similar to animals than other
organisms, this makes fungal diseases very
difficult to treat

4. Classification of FUNGI
•Historically classified by characteristics of sexual
spores and fruiting bodies
•More recently, molecular data
•DNA
•RNA
•Currently classified into THREE kingdoms

5. Classification of Fungi
The last two decade have brought a number of
changes on fungal systematic.
•Wittaker in 1962 broke the classification of living -
organisms that consist of (Prokaryotes, Animal, and
Plant including fungi)
•This classification did not reflect the relationships
between microorganisms. Wittaker made new
taxonomy based on phylogenetic relationships .

7. • At least 7 kingdoms are now recognized (Patterson & Sogin 1992) :
• Based on molecular evidence: base sequences
• from ribosomal RNA (Patterson & Sogin 1992)
• Eubacteria,
• Archaebacteria,
• Animalia,
• Plantae,
• Eumycota,
• Stramenopila (Chromista),
• Protoctista (Protozoa, Protista)

9. 1-Kingdom: Protista (protozoa)
• Phylum (Division): 1- Myxomycota
2-Plasmodiophoramycota
3-Dictyosteliomycota
4-Acrasiomycota
These organisms exhibit phagotrophic
nutrition, decomposers
2-Kingdom: Chromista (Stramenopila)
•Phylum (Division): 1- Oomycota
2-Hyphochytridiomycota
3-Labyrinthulomycota

10. Characters of chromista:
Generaly thallus coenocytic
- Cell wall cellulose and glucan
- diploid
Pathogen to human, plant and animals

11. 3-Kingdom: Fungi (truefungi) (Eumycota)
Phylum (Division): 1. Chytridiomycota
2. Zygomycota
3. Ascomycota
4. Basidiomycota
5-Deuteromycota (fungi imperfecti)

12. Phylum Chytridiomycota
• Earliest fungal phlyum to diverge
• Relatively simple; most unicellular
• ONLY FUNGI with flagellated cells
• Most have no sexual reproduction
• Most decomposers; few cause disease

14. Some species are saprotrophic; others are parasites of
plants, animals, algae and other fungi
Dead frog with chytridiomycosis

15. Zygomycota: The Conjugation
Fungi
The Zygomycota, or conjugation fungi, include
molds, such as those that invade breads and other
food products. The identifying characteristics of the
Zygomycota are the formation of a zygospore during
sexual reproduction and the lack of hyphal cell walls
except in reproductive structures. Many (~100
species) are known plant root symbionts

16. • several species of zygomycota cause serious human infections
and animals
• They are being increasingly used in the biological control of
insect pests of crops.

17. Rhinocerebral zygomycosis (disease )
• Sexual Reproduction - zygosporangia
• Asexual reproduction– by common (sporangia – bags of
asexual spores)

18. Phylum Ascomycota
“sac fungi” or “cup fungi”
•Includes yeasts, powdery mildews, molds
•Hyphae with perforated septa
•Asexual reproduction by conidiophores

19. • The Ascomycota are morphologically diverse. The group includes
organisms from unicellular yeasts to complex cup fungi.
• Characterized by:-
• First, they can produce conidiophores for asexual reproduction.
• Secondly, ascomycota produce structures
• for sexual reproduction called Asci .

20. •There are many famous and infamous
organisms: Saccharomyces cervisiae (baker's
yeast), Penicillium chrysogenum (penicillin), Morchella
esculentum (morels), Neurospora crassa,
•Used in genetic studies and molecular studies
Aspergillus flavus (aflatoxin),producing and
ochratoxin . Ergot, a valuable drug,

22. Phylum Basidiomycota
•Also called “club fungi”
•Mushrooms, bracket fungi, puffballs
•The members include rusts, smuts, mushrooms, puff
balls, toad stools, bracket fungi etc.

23. Basidiospores are developed exogenously
on the horn-shaped structure, called
sterigmata (generally 4) on the Basidium

25. Fairy Ring

27. A large specimen can be
almost two feet long and
contain 7 trillion spores.

28. •Basidiomycota play a significant role in the carbon
cycle. Unfortunately, Other Basidiomycota cause
diseases in animals, including humans.
Basidiomycota frequently attack the wood in
buildings and other structures, which has negative
economic consequences for humans.

29. PHYLUM DEUTEROMYCOTA
No Longer Exist!!
• 22,000 species.
• No known sexual stage.
• Saprophytic, parasitic and predatory.
• Many produce conidia.
• Most classified as Ascomycota.
• Fusarium wilt of tomato, potato and
cotton.
• Athletes foot, ring worm

30. phyllumDeuteromycota
“Imperfect fungi”(Penicillium
sp. and Aspergillus sp. )
Unrelated group
Asexual stage only
No informations on sexual
cycle
25,000 species

31. The class Deuteromycotina has great eco-
nomic importance. Some members cause
different plant diseases, others cause several
diseases of human being, and still others are
very useful in controlling a number of soil
borne plant diseases.

33. Fungal states
•Teleomorph: the sexual reproductive stage
(morph),Emericella nidulans.
•Anamorph: an asexual reproductive stage (morph),
often mold-like (e.g. Aspergillus nidulans .
•Holomorph: the whole fungus, including all
anamorphs and the teleomorph.

34. Homothallic fungi
• possess both male and female nuclei derived from the same thallus for
sexual reproduction. They do not need a partner for sexual
reproduction. This is a form of self-fertilization or
selling. Homothallism is a common condition in fungi . it causes
reduced genetic variability.
• Self – fertile fungi

35. Heterothallic fungi
• are the fungal strains which bear one type of mating type.
They are unisexual in nature. Sexual reproduction of
heterothallic fungi occurs between two different compatible
mycelia. the genetic variation within the populations is high.
• Self – sterile fungi.
What is the difference between Homothallic and
Heterothallic Fungi?

36. Sexuality
Mycelium of the homothallic fungi is bisexual. Mycelium of the heterothallic fungi is unisexual.
Type of Sexual Reproduction
Homothallic fungi perform self-fertilization. Heterothallic fungi perform outcrossing.
Genetic Variation
Homothallic fungal sexual reproduction reduces genetic variation. Heterothallic fungal sexual reproduction increases genetic variation.
Requirement for a Mating Partner
Homothallic fungi do not depend on a mating partner from another thallus. Heterothallic fungi need a different but compatible mating partner.
Mating Partner
Homothallic mating types are genetically more or less similar. Heterothallic mating types are genetically different.
Examples
Examples of homothallic fungi examples include Aspergillus nidulans,
Neurospora galapagoensis, etc.
Examples of heterothallic fungi include Neurospora Crassa, Saccharomyces
cerevisiae, Aspergillus fumigatus, Aspergillus flavus, etc.