Fungi are a diverse group of eukaryotic organisms that reproduce both sexually and asexually. They include mushrooms, yeasts, molds, and crop parasites. Fungi play important roles in symbiotic relationships with plants. They are classified into two divisions - Myxomycota containing plasmodial fungi and Eumycota containing filamentous fungi. Eumycota is further divided into five subdivisions - Mastigomycotina, Zygomycotina, Ascomycotina, Basidiomycotina, and Deuteromycotina - based on characteristics like cell structure, life cycle, and mode of reproduction. Many fungi are plant pathogens that cause diseases in important crop species

1. Classification of
Fungi
HPP 5121 3 (2+1)
Fundamentals of Plant Pathology
CHRS, Jagdalpur

2. • The fungi are a group of eukaryotic, non-vascular organism. Which are of diverse
forms, sizes, physiology and reproduces both by sexual (meiotic) and asexual
(mitotic) spores.
• Examples of fungi :-Mushrooms, yeasts, molds, Penicillium- the first of the
wonder drugs, penicillin, was isolated from this fungus and crop parasites.
• Fungi are most often associated with the roots of some plant species, and this
type of symbiotic associations is known as mycorrhizae.
• The study of fungi is known as mycology (Mykes = mushroom + logos =
discourse) or mycetology and who study about fungus is known as mycologist.

4. • British mycologist, GC Ainsworth (1905-1998) was former director,
Commonwealth Mycological Institute. His scheme of classification was
considered as an ideal one that reflected natural relationships.
• In this scheme, the fungi were divided into two Divisions.
• Fungi with plasmodium or pseudoplasmodium were classified in the
Division Myxomycota, whilst the majority of fungi, which were filamentous, were
classified in the Division Eumycota.

5. • Based on the presence or absence of Plasmodium and pseudoplasmodium; the
kingdom Mycota is further divided into two divisions:
• Myxomycota i.e., slime molds and Eumycota or true fungi.
• Divisions, ends in mycota are subsequently divided into
subdivision- mycotina,
class- mycetes,
subclass- mycetidae,
order- ales,
Family- aceae.

9. • Important features:
i. Free-living, parasitic or mutualistic symbionts, devoid of chlorophyll.
ii. Cell wall composition is very variable, majority contain chitin and glucan.
iii. Reserve food materials are oil, mannitol and glycogen.
iv. Except some unicellular members, majority are filamentous.

10. DIVISION- MYXOMYCOTA
• Wall-less organisms possess either a Plasmodium (a mass of naked multinucleate
protoplasm having amoeboid movement) or a pseudoplasmodium (an
aggregation of separate amoeboid cells).
• Both are of slimy consistency, hence slime molds.
1. Class- Acrasiomycetes (cellular slime molds)
2. Class- Hydromyxomycetes (net slime molds)
3. Class- Myxomycetes (true slime molds)
4. Class- Plasmodiophoromycetes (endo- parasitic slime molds).

11. DIVISION EUMYCOTA
• (TRUE FUNGI, ALL WITH WALLS)
• Thallus is typically filamentous with cell wall. Plasmodium absent.
Five subdivision
1. Mastigomycotina
2. Zygomycotina
3. Ascomycotina
4. Basidiomycotina
5. Deuteromycotina

12. The important characteristics of Mastigomycotina are:
i. The subdivision Mastigomycotina is commonly known as zoosporic fungi
ii. Members of this group vary from unicellular plant body (with or without rhizoid)
to filamentous coenocytic mycelium.
iii. Sexual reproduction takes place by gametic copulation, gametangial copulation
and gametangial contact
Key to classes of Mastigomycotina:
A. Class- Chitridiomycetes
B. Class- Hypochitridiomycetes
C. Class- Oomycetes

13. Some important parasitic members of this group are:
• Pythium. Different species of Pythium cause foot rot, fruit
rot, rhizome rot and damping off.
• Phytophthora. Different species of Phytophthora cause stem
and leaf blight, foot rot, leaf rot, corm rot, fruit rot etc.
• Albugo. Different species of Albugo cause white rust disease
of different hosts like crucifers (cabbage, Brassica, radish,
turnip etc.

15. The Important Characteristics
• The fungi belonging to this group are generally terrestrial and they produce
zygospore (Gr. zygos — yoke; Spora — seed, spore) after sexual reproduction.
• The thallus is normally haploid, consisting of coenocytic mycelium and its cell wall
contains chitin.
• Asexual reproduction takes place by aplanospores.
• Sexual reproduction takes place by gametangial copulation, resulting in the
formation of zygospore.
.

16. two classes:
i. Zygomycetes,
ii. Trichomycetes
Some important parasitic members of this group are:

18. • The Ascomycotina (Gr. askos— sac or bladder; mykes — fungi), commonly known as
“sac fungi”, is the largest group under the Kingdom Fungi, comprised of six classes and
about 30,000 species.
• live in salt, freshwater and terrestrial habitats.
• Vegetative body is unicellular or commonly well-developed, branched septate mycelium
with uni or multinucleate cells having perforated septa.
six classes, namely:
i. Hemiascomycetes,
ii. Loculoascomycetes,
iii. Plectomycetes,
iv. Laboulbeniomycetes,
v. Pyrenomycetes,
vi. Discomycetes.

19. Some important parasitic members of this group are:
• Its includes morels, powdery mildews, yeasts and cup fungi

21. • The subdivision included about 500 genera with more than 16,000 species.
• Basidiomycotina are characterized by the formation of basidiospores and absence
of flagellated structure.
Three classes
1 Teliomycetes
2 Hymenomycetes
3 Gasteromycetes

22. Some important parasitic members of this group are:
• The members include rusts, smuts, mushrooms, puff balls, toad stools, bracket
fungi etc. Rust (Puccinia spp.) and smuts (Ustilago spp.)

24. • The subdivision Deuteromycotina is also known as Fungi imperfecti or Waste Box
Fungus, due to lack of knowledge on sexual reproduction.
• C. T. Ingold called Deuteromycotina the “dust bin” group because of their
doubtful systematic position.
• Its include about 600 genera and over 20,000 species.
• Members are not closely related and are not necessarily similar in structure or
appearance; do not share a common ancestry

25. Some important parasitic members of this group are:
• Leaf spot of curcifers, Early blight of potato, Brown spot of rice, Tikka or Leaf spot
of groundnut

26. Life cycle of Alternaria

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