1. Filamentous fungi - a background
Lecture 2

2. Fungi are important in nature
As decomposers
As pathogens of plants, animals and humans, and in food spoilage
As producers of secondary metabolites, e. g. penicillin
In cheese, bread and wine making

3. Four phyla of fungi Chytridiomycota - no sexual spore
Zygomycota - zygospore
Ascomycota - ascospore
Basidiomycota - basidiospore

4. Fungal reproduction Asexually, by forming conidia
Sexually (three steps):
Plasmogami (dikaryon)
Karyogami (zygote forms)
Meiosis (sexual spore forms):
Zygospore
Ascospore
Basidiospore

5. Chytridiomycota

6. Zygomycota

7. Gametangia fuse to produce a zygospore (Rhizopus stolonifer)

8. Ascomycota

9. Ascomycota - 32 300 described species
Powdery mildews
Nectria cankers of trees (Nectria galligena)
Brown rot of stone fruit (Monilia fructicola)
Chestnut blight (Cryphonectria parasitica)
Dutch elm disease (Ophiostoma ulmi)
Most yeasts
Morels and truffles

10. Characteristics of Ascomycota
Septate hyphae
Uninucleate or multinucleate hyphae
Heterothallic or homothallic
Sexual spore = ascospore, produced in sac called ascus. Usually 8 ascospores per ascus.
Ascocarp (fruiting body) can be of three different types: cleistothecium, perithecium or apothecium.

12. Botrytis cinerea - a fungus -causes grey mold

13. Powdery mildew of cucumber

14. Cleistothecia of powdery mildew

15. Anthracnose of cucurbits
Anthracnose of melon caused by Colletotrichum orbiculare

16. Eye spot disease of strawberry Ramularia grevilleana, Mycosphaerella fragariae

17. Canker, Nectria galligena

18. Perithecium of Nectria galligena

19. Penicillium and Aspergillus

20. Examples of conidiophores of other imperfect fungi or Deuteromycetes

21. Wilts caused by Fusarium oxysporum
Darkened vascular tissue of cucumber caused by F. ox. f.sp. cucumerinum
Wilt of field grown melon caused by F. ox. formae speciales melonis

22. Life cycles of fusarium wilts

23. Basidiomycota - 22 300 described species
Mushrooms, stinkhorns, puffballs (Basidiomycetes)
Rusts (Teliomycetes)
Smuts (Ustomycetes)
Basidiospores (sexual spore) made on club-like structure, called basidium.

24. Basidiomycota

25. Characteristics of Basidiomycota
Mycelium is septate
Septa are perforated - sometimes with dolipore (doughnut shaped)

26. Characteristics of Basidiomycota
Mycelium passes two phases - monokaryotic and dikaryotic.
Two hyphal ends of the monokaryotic mycelium (of different mating types) fuse and produce the dikaryotic mycelium.
The dikaryotic mycelium can divide at the apical cell and form clamp connections.

27. Basidiomycetes have clamp connections

28. “Fairy ring”
Fruiting bodies

29. Fly agaric (flugsvamp)

30. Hallocinogenic fungi Psilocybe mexicana Psilocybin
Mushrooms are part of many religious ceremonies in Mexico and Central America. Psilocybe mexicana is a fungus that contains the hallucinogenic drug psilocybin, which is related to LSD and mescaline.

31. Rhizoctonia solani
It is a basidiomycete; teliomorph (Thanatephorus cucumeris) is rare.
Has very characteristic mycelium; typical of basidiomycete.
Differentiated into anastomosis groups (AG) (fusion of hyphae only occur if same anastomosis group)

32. The disease cycle of Rhizoctonia solani

33. Characteristics of the rusts (Teliomycetes)
Sori, in which uredospores are formed.
Were thought to be obligate parasites, but some can be grown in the laboratory.
Can live on one host - autoecious, or two hosts - heteroecious.
New races appear constantly; difficult to control.
Spore forms: basidiospore (n), aeciospore (n+n), uredospore (n+n) and teliospore (2n).

34. Rusts

35. Wheat stem rust (Puccinia graminis)

36. Stem rust of wheat

38. Rust of roen (rönn)

39. Rust of raspberry

40. Disease cycle of cedar-apple rust

41. Rust of rose

42. Uredospores of rose rust

43. Teleutospores, rose rust

44. Corn smut

45. Corn smut

46. The life cycle of smut fungi
Teliospores (2N)
(sexual spores)
Infection
Meiosis
Mating
Budding cells (1N)
Filamentous
Dikaryon (N+N)
The life cycle of smut fungi
Chlamydospores (1N)
(asexual spores)