Classification of fungi

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…
•Likeanimalcells,fungalcellshaveplate-like
cristaeintheirmitochondria.
•Becausefungiaremorechemicallyand
geneticallysimilartoanimalsthanother
organisms,thismakesfungaldiseasesvery
difficulttotreat

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
Thelasttwodecadehavebroughtanumberof
changesonfungalsystematic.
•Wittakerin1962broketheclassificationofliving-
organismsthatconsistof(Prokaryotes,Animal,and
Plantincludingfungi)
•Thisclassificationdidnotreflecttherelationships
betweenmicroorganisms.Wittakermadenew
taxonomybasedonphylogeneticrelationships.

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. Charactersofchromista:
Generalythalluscoenocytic
-Cellwallcelluloseandglucan
-diploid
Pathogentohuman,plantandanimals

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
TheZygomycota,orconjugationfungi,include
molds,suchasthosethatinvadebreadsandother
foodproducts.Theidentifyingcharacteristicsofthe
Zygomycotaaretheformationofazygosporeduring
sexualreproductionandthelackofhyphalcellwalls
exceptinreproductivestructures.Many(~100
species)areknownplantrootsymbionts

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. •Therearemanyfamousandinfamous
organisms:Saccharomycescervisiae(baker's
yeast),Penicilliumchrysogenum(penicillin),Morchella
esculentum(morels),Neurosporacrassa,
•Usedingeneticstudiesandmolecularstudies
Aspergillusflavus(aflatoxin),producingand
ochratoxin.Ergot,avaluabledrug,

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. •Basidiomycotaplayasignificantroleinthecarbon
cycle.Unfortunately,OtherBasidiomycotacause
diseasesinanimals,includinghumans.
Basidiomycotafrequentlyattackthewoodin
buildingsandotherstructures,whichhasnegative
economicconsequencesforhumans.

29. PHYLUM DEUTEROMYCOTA
No Longer Exist!!
•22,000 species.
•No known sexual stage.
•Saprophytic, parasitic and predatory.
•Many produce conidia.
•Most classified as Ascomycota.
•Fusariumwilt 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. TheclassDeuteromycotinahasgreateco-
nomicimportance.Somememberscause
differentplantdiseases,otherscauseseveral
diseasesofhumanbeing,andstillothersare
veryusefulincontrollinganumberofsoil
borneplantdiseases.

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
•possessbothmaleandfemalenucleiderivedfromthesamethallusfor
sexualreproduction.Theydonotneedapartnerforsexual
reproduction.Thisisaformofself-fertilizationor
selling.Homothallismisacommonconditioninfungi.itcauses
reducedgeneticvariability.
•Self–fertilefungi

35. Heterothallic fungi
•arethefungalstrainswhichbearonetypeofmatingtype.
Theyareunisexualinnature.Sexualreproductionof
heterothallicfungioccursbetweentwodifferentcompatible
mycelia.thegeneticvariationwithinthepopulationsishigh.
•Self–sterilefungi.
WhatisthedifferencebetweenHomothallicand
HeterothallicFungi?

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 includeAspergillusnidulans,
Neurosporagalapagoensis,etc.
Examples of heterothallic fungi includeNeurosporaCrassa,Saccharomyces
cerevisiae,Aspergillusfumigatus,Aspergillusflavus,etc.