1. Basidiomycetes AN INTRODUCTION TO FUNGI, ALGAE AND PLANTS:
THEIR MORPHOLOGY, CLASSIFICATION AND EVOLUTION
THIRD EDITION
JOHN C. SEMPLE
AsterGraphics, Waterloo
ISBN   
© J.C. Semple, 2004

2. Dikaryomycota – two haploid nuclei
Dominant stage of many species  haploid
Mating: plasmogamy  karyogamy
Between these stages the cell is dikaryotic
Dikaryotic hyphae contain two types of haploid nuclei
Plasmogamy is separate from karyogamy

3. Two groups of Basidiomycetes
Holobasidiomycetes
Heterobasidiomycetes

4. AN INTRODUCTION TO
FUNGI, ALGAE AND PLANTS:
THEIR MORPHOLOGY, CLASSIFICATION AND EVOLUTION
THIRD EDITION
JOHN C. SEMPLE
AsterGraphics, Waterloo
ISBN   
© J.C. Semple, 2004

5. Holobasidiomycete characteristics
Basidium lacking septa
Synchronous spore maturation
Mushrooms
many are mycorrhizal with trees
some saprobes, some pathogens
Bracket fungi – saprobic on trees
Puffballs
Sterigma (pl. sterigmata)

6. Heterobasidiomycete characteristics
Basidia having septa
Asynchronous spore maturation
Rusts and smuts – obligate plant pathogens
Sterigma (pl. sterigmata)
septa

7. Holobasidiomycetes – mushroom life cycle
Dikaryotic hyphae
Basidiomata initiation is triggered by environmental conditions, including moisture
Hymenium – fertile layer

8. Basidium development in the hymenium
karyogamy
meiosis 2
meiosis 1
nuclear migration

9. Nuclei are extremely flexible: they migrate through the sterigma / spore junction
basidiospore
sterigma

10. The hymenium can be on ...
Gills
Pores
Teeth

11. Gilled mushrooms
Agaricales
Lactarius
indigo

12. Gills are covered with basidia
Coprinus cinereus

13. Holobasidiomycetes – Polyporales
Pore shape is important in identification
Fomes fomentarius

14. Pores are lined with basidia

15. Tooth mushrooms – Hydnales
Teeth are covered with basidia
Hydnum repandum

16. Auriscalpium vulgare

17. Getting spores out of tight places
Gills and pores can be tightly packed / tiny, and shielded from breezes

18. Cystidia keep gills properly spaced

19. Getting spores out of tight places
Buller’s drop is a launching mechanism

20. Hilar appendage on ballistic basidiospores

22. The importance of being vertical
Basidiomata can reorient their growth so gills/pores are perpendicular

23. Some mushroom caps seem poorly designed for air dispersal of spores
Coprinus comatus
Common in Saskatchewan, especially in autumn on/near tree stumps

24. Autolysis can modify cap shape
Inky cap – water dispersal

25. Partial veil Universal veil

26. How mushroom caps get spots and scales

27. Water-dispersed spores: puffballs
Lycoperdon gemmatum

28. Water-dispersed spores: birds’ nests
Splash cup
Funicular thread

29. Heterobasidiomycetes have septate basidia

30. Heterobasidiomycetes – obligate plant pathogens – rusts and smuts
Puccinia graminis f. sp. tritici
Aecial stage, on barberry
Ustilago maydis on corn

31. Wheat stem rust Puccinia graminis f. sp. tritici
Five spore stages
Pycnia, aecia, uredia, telia, basidia
Two hosts
Barberry – sporidia/pycnia, aecia
Wheat – uredia, telia, basidia
Uredial stage is most damaging to crops

32. Wheat stem rust uredia
Rust-coloured urediospores

33. Nutrient extraction by haustoria

34. Overwintering as teliospores
meiosis
karyogamy

35. Some rust fungi require two hosts!
Heteroecious  “other houses”
“Microcyclic” rusts have reduced numbers of spore types

36. Sexual recombination in wheat stem rust

37. ... house-eating HolobasidiomyceteS
Poria incrassata
Serpula lacrymans
DRY ROTS

38. Fungi imperfecti (Deuteromycetes)
Next time
Fungi imperfecti (Deuteromycetes) or
Life without sex
(really)