Chapter 25 Fungi

Fig. 31-1

Fig Reproductive structure Spore-producing structures Hyphae Mycelium 20 µm

Fig (b) Coenocytic hypha Septum (a) Septate hypha Pore Nuclei Cell wall

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

Fig µm

Fig µm Parent cell Bud

Fig Chytrids (1,000 species) Zygomycetes (1,000 species) Hyphae 25 µm Glomeromycetes (160 species) Fungal hypha Ascomycetes (65,000 species) Basidiomycetes (30,000 species)

Fig Rhizopus growing on bread SEXUAL REPRODUCTION Young zygosporangium (heterokaryotic) Gametangia with haploid nuclei Mating type (–) Mating type (+) Diploid (2n) Haploid (n) Heterokaryotic (n + n) PLASMOGAMY Key Diploid nuclei Zygosporangium 100 µm KARYOGAMY MEIOSIS Sporangium Spores Dispersal and germination ASEXUAL REPRODUCTION Dispersal and germination Sporangia Mycelium 50 µm

Glomeromycetes The glomeromycetes (phylum Glomeromycota) were once considered zygomycetes They are now classified in a separate clade Glomeromycetes form arbuscular mycorrhizae

Fig µm

Fig Tuber melanosporum, a truffle Morchella esculenta, the tasty morel

Fig Key Haploid (n) Diploid (2n) Dikaryotic (n + n) Conidiophore Mycelium ASEXUAL REPRODUCTION Germination Hypha PLASMOGAMY Haploid spores (conidia) Conidia; mating type (–) Mating type (+) SEXUAL REPRODUCTION Dikaryotic hyphae Ascus (dikaryotic) Mycelia KARYOGAMY Diploid nucleus (zygote) Germination Asci Dispersal Ascocarp Eight ascospores Four haploid nuclei MEIOSIS

Fig a Maiden veil fungus (Dictyphora), a fungus with an odor like rotting meat

Fig b Puffballs emitting spores

Fig c Shelf fungi, important decomposers of wood

Basidium Fig SEXUAL REPRODUCTION Diploid (2n) Haploid (n) Dikaryotic (n +n) Key PLASMOGAMY Mating type (+) Haploid mycelia Dikaryotic mycelium Mating type (–) Basidia (n+n) Gills lined with basidia Basidiocarp (n+n) KARYOGAMY Diploid nuclei MEIOSIS Basidium containing four haploid nuclei Dispersal and germination Basidiospores (n) Basidium with four basidiospores Basidiospore 1 µm Haploid mycelia

Fig

Fig a A fruticose (shrublike) lichen

Fig b Crustose (encrusting) lichens

Fig c A foliose (leaflike) lichen

Fig Algal cell Ascocarp of fungus Soredia Fungal hyphae Fungal hyphae Algal layer 20 µm

Fig a (a) Corn smut on corn

Fig b (b) Tar spot fungus on maple leaves

Fig c (c) Ergots on rye

Fig Staphylococcus Zone of inhibited growth Penicillium

Fig. 31-UN6a

Fig. 31-UN6b

Fig. 31-UN6c

Fig. 31-UN6d

Fig. 31-UN6e

You should now be able to: 1.List the characteristics that distinguish fungi from other multicellular kingdoms 2. Describe the life cycles of Rhizopus stolonifer and Neurospora crassa 3. Distinguish among zygomycetes, ascomycetes, and basidiomycetes 4. Describe some of the roles of fungi in ecosystems, lichens, animal-fungi mutualistic symbioses, food production, and medicine and as pathogens