This presentation describe classification and main diagnostic characteristics of important plant pathogenic fungi.

1. Classification and Main Diagnostic
Characteristics of Important Fungi
DR. RAJBIR SINGH
Assistant Professor
Department of Plant Pathology
Gochar Mahavidyalaya (Post Graduate College)
Rampur Maiharan, Saharanpur (UP), India
Affiliated to: CCS University, Meerut (UP), India
Email: rajbirsingh2810@gmail.com

2. Pytophthora
Classification
Kingdom : Mycota
Division : Eumycota
Subdivision : Mastigomycotina
Class : Oomycetes
Order : Pernosporales
Family : Pythiaceae
Genus : Phytophthora

3. Phytophthora
• Thallus is mycelial type and mycelium is branched, non-septate and
hyaline.
• The hyphae are localised in both intracellular and inter-cellular
position.
• Haustorium is present.
• Asexual reproduction by zoospores which are produced in sporangia.
• The superficial somatic hyphae produce abundant sporangiophores.
• Sporangiophore is sympodially branched at maturity and produces
sporangia laterally. It is very little differentiated from the somatic
hyphae.
• Sporangium is thin-walled, lemon-shaped with an apical papilla.
• Sexual reproduction by oospore.
• Oospore is thick-walled, spherical and develops singly in each
oogonium. It is formed by the union of antheridium and oogonium
arranged in amphigynous manner.

4. Sporangia of Phytophthora

5. Pernospora
Classification
Kingdom : Mycota
Division : Eumycota
Subdivision : Mastigomycotina
Class : Oomycetes
Order : Pernosporales
Family : Pernoporaceae
Genus : Pernospora

6. Pernospora
• Mycelium is coenocytic, branched and intercellular.
• The haustoria are present which are short and knob-like or
filamentous and branched.
• Sporangiophore is dichotomously branched and projected from
the host-tissue, mostly through stomata covering the greenish
part of the host with a dense white growth, called “downy
mildew”.
• Sporagium are borne singly at the acute, more or less reflexed
tips of the branched sporangiophores.
• Each sporangium appears elliptical to globose, blunt, without
any apical papilla. They are hyaline or light-coloured.
• Oospore is thick-walled and somewhat spherical. It is formed by
the union of antheridium and oogonium. Each oogonium has
one oospore with periplasm
• Gametangia morphologically distinguishable as male and female
gametangia.

8. Sclerospora
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Mastigomycotina
Class : Oomycetes
Order : Pernosporales
Family : Pernosporaceae
Genus : Sclerospora

9. Sclerospora
• Mycelium is eucarpic, filamentous, coenocytic endoparasitic , branched.
• The hyphae are intercellular and freely branched.
• Cell wall is made of cellulose and food is stored in the form of glycogen.
• Haustoria is present which are digitate button shaped in the stem cells but
are simple branched finger shaped occupying a major portion of the cell
cavity of the leaf.
• Asexual reproduction by sporangia and conidia.
• sporangium is hyaline, round or elliptical slightly papillate at the apex and
measure 13-34 x 12-23 µ in size.
• The sporangiophores emerge out of the stomata of the infected leaves. Each
sporangiophore is a stout broad hypha unbranched in the lower part but giving
out a few (2-6) thick short branches, di—or trichotomously, at the upper part.
It is 100 µ length and 10-15 µ in width.
• Conidiophores are less branched.
• Conidium size is 13 × 12µm.
• Sexual reproduction by oospore.

11. Ustilago
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Basidiomycotina
Class : Teliomycetes
Order : Ustilaginales
Family : Ustilaginaceae
Genus : Ustilago

12. Ustilago
• Mycelium is septate, branched, inter to intracellular,
monokaryotic an dikaryotic
• Basidiocarp is absent.
• Basidium is septate
• Chlamydospore originate from mycelium present in
host tissues
• Chlamydospores are sessile, shperical and black in
color.
• Chlamydospres are not stick in pairs.
• Articulation on the surface of spore is present.
• In later stage spores seems as black dust.

13. Smut Spores of Ustilago

14. Sphacelotheca
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Basidiomycotina
Class : Teliomycetes
Order : Ustilaginales
Family : Ustilaginaceae
Genus : Sphacelotheca

15. Sphacelotheca
• Mycelium is septate.
• Clamp connection in mycelium present.
• Basidiocarp is absent.
• Sexual reproduction by basidiospres which are 4 in
number.
• Basidium is septate.
• Chlamydospore originate from mycelium present in
host tissues
• Chlamydospores are sessile and black in colour.
• Diameter of smut spore is 5-9µ.
• No articulation on the outer surface of spores.

16. Smut Spores

17. Tolyposporium
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Basidiomycotina
Class : Teliomycetes
Order : Ustilaginales
Family : Ustilaginaceae
Genus : Tolyposporium

18. Tolyposporium
• Mycelium is septate and branhed.
• Smut spore originate from mycelium present in
host tissues.
• Infected grains by this genus converted in sourus.
• Sourus is generally 3-4mm × 2-3mm in size.
• Smut spores are egg shaped, rough wall and light
brown in color.
• Diameter of smut spore is 8-12µ.
• Smut spores are in the form of spare balls which
are transmitted by air.
• Basidiocarp absent.
• Basidium form exogenously on mycelium.

20. Melampsora
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Basidiomycotina
Class : Teliomycetes
Order : Uredinales
Family : Melampsoraceae
Genus : Melampsora

21. Melampsora
• Fungus is obligate parasite and cause macro cyclic and
autocious rust.
• Mycelium is dicaryotic and intercellular.
• No basidiocarp.
• Urediospores are small and orange in color.
• Urediospores are spiny, round shaped and size -15-25µ ×
13-17µ.
• Teliospores form on lower side of epidermis.
• Teliospores are cylindrical, unicellular and size – 46-48µ ×
8-20µ.

23. Alternaria
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Deuteromycotina
Class : Hyphomycetes
Order : Moniliales
Family : Dematiaceae
Genus : Alternaria

24. Alternaria
• Mycelium is short, septate and branched. The hypal cells are
multinucleate.
• There is no sexual reproduction; only asexual mode of
reproduction by conidia is noted.
• Some short and dark-coloured somatic hyphae behave as
conidiophores.
• Conidia are produced at the tips of conidiophores in chains or
singly.
• Conidia are large, elliptical to ovoid, dark coloured, several
celled and beaked.
• The number of cells varies from 8-14 or even more. The septa
dividing the spore into cells are both transverse and vertical.
• Conidia are measuring 20 – 100 µm in length (average 40 µm)
and 5-16 µm in breadth (average 12 µm).

26. Helminthosporium
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Deuteromycotina
Class : Hyphomycetes
Order : Moniliales
Family : Dematiaceae
Genus : Helminthosporium

27. Helminthosporium
• Mycelium is septate, branched and multinucleate.
• Sex organs and sexual reproduction absent
• It reproduces primarily by conidia borne on
conidiophores.
• Conidiophore- is dark-coloured, erect, branched and
septate. conidiophores are not united together to form
sporodochia, synnemata, accrvulus or pycnidium.
• Conidiophores are grey to olive colored which form in
the group of 3-5.
• Conidia are long, slender, three to 3-7 celled, tapering
upward, hyaline to dark colored and straight or
slightly curved. Conidia are measuring 15 – 30 µm in
length and 4 – 10 µm in breadth.
• Germ tube form from end cells of conidia.

29. Pyricularia
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Deuteromycotina
Class : Hyphomycetes
Order : Moniliales
Family : Dematiaceae
Genus : Pyricularia

30. Pyricularia
• Mycelium is branched, septate with multinucleate
cells.
• Width of mycelium is 1.5- 6µm.
• There is complete absence of sex organs and sexual
reproduction. They produce conidia as a means of
asexual reproduction.
• Conidiophores are hyaline, mostly free, branched,
long, slender and septate. Conidial scars are present
on the conidiophores.
• Conidium is pyriform to ellipsoidal, 2-3 celled,
hyaline and developed either laterally or terminally
on the conidiophores.
• Conidia not borne within a pycnidium or acervulus.
• Size of conidium is 19.2 - 27.3 × 8.1 – 10.3µm.
• Chlamydospores can be produced on medium.

32. Fusarium
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Deuteromycotina
Class : Hyphomycetes
Order : Moniliales
Family : Tuberculariaceae
Genus : Fusarium

33. Fusarium
• Mycelium is septate, branched, transparent
and restricted to vascular tissues of host.
• Sex organs and sexual reproduction absent.
• Two types of conidia (Micro and Macro
conidia) are produce on conidiophores.
• Micro conidia are 5-15 × 2-4µm in size.
• Macro conidia are 15 -20 × 3-5µm in size.
• Chlamydospores are produce inside tissues
and arranged in a chain.

34. Micro conidia Macro conidia
Chalamydospore
Chalamydospores

35. Colletotrichum
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Deuteromycotina
Class : Coelomycetes
Order : Melanconiales
Family : Melanconiaceae
Genus : Colletotrichum

36. Colletotrichum
• Mycelium is septate, branched, dense, inter
or intracellular and colored.
• Asexual reproduction by conidia.
• Conidia form in Acervulus on
conidiophores. Conidiophores are non
septate.
• Acervulus are dark color. Setae are present.
• Conidia are single cell, long or sickle
shaped.

38. Cercospora
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Deuteromycotina
Class : Hyphomycetes
Order : Moniliales
Family : Dematiaceae
Genus : Cercospora

39. Cercospora
• Mycelium is multicellular, branched and septete.
• Mycelium form stromata under the epidermis of host leaves.
• No sexual reproduction.
• Asexual reproduction by conidia.
• No Pycnidia or Acervulus.
• Conidia form on conidiophores.
• Mycelium, conidiophore and conidia are black in color.
• Conidiophores come out from the host groups.
• Conidiophores are geniculate and branched.
• Conidia are curved. Base of conidia are round shaped and top
is acute.
• Conidia are generally 4-5 celled but some time may be 12-15
celled.

41. Rhizoctonia
Classification:
Kingdom : Mycota
Division : Eumycota
Subdivision : Deuteromycotina
Class : Hyphomycetes
Order : Myceliasterilia
Family : Rhizoctoniaceae
Genus : Rhizoctonia

42. Rhizoctonia
• The fungus mostly present in the soil as
parasite and cause root rot and damping off
diseases in plants.
• Mycelium is septate, branched, inter or
intercellular.
• No sexual reproductive organs is present.
Scelerotia form which germinate and form
mycelium.

43. Rhizoctonia