1. Fungi Lab

2. Tentative Phylogeny Fig 28.8

3. Generalized fungal lifecycle Spore-producing structures Spores ASEXUAL REPRODUCTION GERMINATION Zygote Mycelium GERMINATION MEIOSIS Spore-producing structures Spores Key Haploid (n) Heterokaryotic (unfused nuclei from different parents) Diploid (2n) PLASMOGAMY (fusion of cytoplasm) Heterokaryotic stage KARYOGAMY (fusion of nuclei) SEXUAL REPRODUCTION Zygote Mycelium

4. Phylogeny of fungi Chytrids Zygote fungi Arbuscular mycorrhizal fungi Sac fungi Club fungi Chytridiomycota Zygomycota Glomeromycota Ascomycota Basidiomycota

5. Fungal Divisions Chytridyomycota – Aquatic, with flagellated zoospores Diploid phase- sporophyte Zygomycota = zygospores. Resistant zygote sporangium Glomeromycota= zygospores arbuscular mycorrhizae. Ascomycota = ascospores Endogenous meiospores Basidiomycota = basidiospores Exogenous meiospores Deuteromycetes – imperfect, no sexual reproduction

6. Chytridiomycota Chytrids use an absorptive mode of nutrition and have chitin cell walls. There are a few unicellular chytrids, but most form ceonocytic hyphae. Chytrids share key enzymes and metabolic pathways with other fungal groups, but not with the slime molds Ancestral to other three groups on land Forms flagellated zoospores

7. Allomyces Life cycle #13 #14 Diploid Haploid

8. Allomyces gametophyte (n) slide

9. Gametophyte

10. Sporophyte Meiosporangia

11. Allomyces (2n) Fresh Sample

12. Fungal Divisions Chytridyomycota – Aquatic, with flagellated zoospores Diploid phase- sporophyte Zygomycota = zygospores. Resistant zygote sporangium Glomeromycota= zygospores arbuscular mycorrhizae. Ascomycota = ascospores Endogenous meiospores Basidiomycota = basidiospores Exogenous meiospores Deuteromycetes – imperfect, no sexual reproduction

13. Zygomycete lifecycle #16 #15

14. Zygosporangium formation +, - suspensor hyphae grow together. Each tip cuts off a gametangia with complete septa. Gametangia fuse into one large heterokaryont. Nuclei pair up form many diploid nuclei. Resistant wall forms on Zygosporangium Before germination meiosis takes place Forms sporangia, releasing haploid spores

15. Asexual Spore formation Haploid nuclei migrate to swollen hyphal tip. Hyphal tip forms complete septum, now a sporangium. Each nucleus forms a spore around itself with cytoplasm, endospores. Sporangium wall breaks. Spores blow away.

16. Phycomyces suspensors

17. Phycomyces on low power Zygosporangia

18. Phycomyces Gametangia fusing

19. Pilobolus Sporangium with mitospores Swollen sprangiophore

20. Spore dispersal

21. Positive Phototropism

22. Fungal Divisions Chytridyomycota – Aquatic, with flagellated zoospores Diploid phase- sporophyte Zygomycota = zygospores. Resistant zygote sporangium Glomeromycota= zygospores arbuscular mycorrhizae. Ascomycota = ascospores Endogenous meiospores Basidiomycota = basidiospores Exogenous meiospores Deuteromycetes – imperfect, no sexual reproduction

23. Mycologists have described over 60,000 species of ascomycetes, or sac fungi. They range in size and complexity from unicellular yeasts to elaborate cup fungi and morels. Ascomycota: Sac fungi produce sexual spores in saclike asci

24. Ascomycetes are characterized by an extensive heterokaryotic stage during the formation of ascocarps. Fig. 31.10

25. Ascus formation Hyphal tip makes complete septum, Nuclei fuse – a single 2n nucleus Meiosis – 4 haploid nuclei One mitotic division – 8 haploid nuclei Each nucleus cuts off some cytoplasm and forms new wall, inside original hyphae wall. 8 ascospores are forcibly ejected by osmotic pressure. Different forms of ascocarp have evolved.

26. Ascospore formation Zygote Meiosis Mitosis Spore wall N+N

27. Peziza sp. apothecia

29. Apothecia- #18

30. Asci – Slide #18

31. Morchella sp.

32. Morchella x-section

33. Morchella slide

34. Sordaria- perithecia

35. Sordaria slide #

36. Fresh Sordaria slide

37. Saccharomyces cervisea Budding

38. Conidia Many Ascomycetes reproduce asexually by producing enormous numbers of Conidia, asexual spores, (exogenous mitospores) which are usually dispersed by the wind. Conidiophore continuously divides forming more spores at tip.

39. Fungal Divisions Chytridyomycota – Aquatic, with flagellated zoospores Diploid phase- sporophyte Zygomycota = zygospores. Resistant zygote sporangium Glomeromycota= zygospores arbuscular mycorrhizae. Ascomycota = ascospores Endogenous meiospores Basidiomycota = basidiospores Exogenous meiospores Deuteromycetes – imperfect, no sexual reproduction

40. Basidiomycota Typical Mushroom Almost no asexual reproduction Many mycorrhizae species Oldest organism ? Mushrooms caps have basidia on gills. The spores drop beneath the cap and are blown away.

42. The life cycle of a Basidiomycete usually includes a long-lived dikaryotic mycelium. Fig. 31.12

43. Basidia formation

44. Coprinus

45. Basidiospores

47. Lichens Symbiosis of –Phycobiont, algae / cyanobacteria –Mycobiont - fungi. Not individual organisms Primary colonizers of new land in succession, and in tundra areas Soredia asexually reproduce lichen –Fungi often reproduce on their own. Lichen acids, dyes

48. Fig. 31.17

49. Three growth forms: 1.Crustose – flat on stones 2.Foliose- leaf-like as in picture 3.Fruticose- upright growing Phycobiont in inner layers protected by fungi on top and bottom

50. (a) A fruticose (shrub-like) lichen (b) A foliose (leaf-like) lichen (c) Crustose (crust-like) lichens

51. Physcia # 28 Ascocarp Phycobiont

52. Umbilicaria sp. Upper Cortex Phycobiont layer Filamentous Hyphal layer medulla Lower Cortex

53. Glomeromycota Has some characteristics similar to zygomycetes. DNA comparisons show then to be their own group Form Arbscular endomycorrhizae

55. Endotropic Mycorrhizae

56. Arbuscular mycorrhizae 2.5  m Plant cell wall