1 Chapter 20 Kingdom Fungi FUNGI: FRIENDS AND FOES TRAITS OF TRUE FUNGI True Fungi Are Eukaryotic, Spore- producing Heterotrophs with Chitinous Walls Most Fungi Have Bodies Called Mycelia Mycelia Compete Well with Bacteria ECOLOGICAL STRATEGIES OF FUNGI REPRODUCTIVE STRATEGIES FUNGAL ORIGIN, CLADES, AND GRADES True Fungi Are a Monophyletic Kingdom of Life Sexual Reproduction and Flagellation Define Traditional Phyla Fungal Systematics Is a Work in Progress Dikaryomycetes and Coenomycetes Are Grades of Fungal Evolution PHYLUM CHYTRIDIOMYCOTA PHYLUM ZYGOMYCOTA PHYLUM GLOMEROMYCOTA PHYLUM ASCOMYCOTA Ascomycetes Make Septate Hyphae and Conidia Ascomycetes Have a Short but Powerful Dikaryotic Stage There Are Three Main Types of Ascomata Many Ascomycetes Engage in Symbiosis Most Mitosporic and Dimorphic Fungi Are Ascomycetes PHYLUM BASIDIOMYCOTA Hymenomycetes Make Long-lived Dikaryons Hymenomycetes Make varied Fruiting Bodies Ballistospore Release Aids in Dispersing Basidiospores Many Ustilaginomycetes Cause Smut Diseases Urediniomycetes Cause Rust Diseases SUMMARY IN DEPTH: Microsporidia: Fungi in Disguise? IN DEPTH: The Hat Thrower
2 KEY CONCEPTS 1. Kingdom Fungi (the true fungi) is a monophyletic group of eukaryotic heterotrophs that reproduce with spores and have chitinous cell walls. The most familiar fungi are kitchen molds and mushrooms. The kingdom may include 1.5 million species, of which about 80,000 species have been named and described. 2. Some fungi destroy crops and stored food. Others are valuable decomposers or symbionts that cohabit with algae and cyanobacteria or assist plant growth. Baker's yeast is a fungus, and penicillin is a fungal product. 3. Most fungi develop a mycelium, composed of branching threads (hyphae) that collect nutrients and produce reproductive structures. Some fungi have a simpler thallus or live as microscopic unicells (yeasts). Dimorphic fungi make both mycelia and yeasts. 4. Many fungi make asexual spores to multiply and sexual spores for diversity. Exceptions include mushroom fungi, which use sexual spores to multiply, and mitosporic fungi, which have not been observed to reproduce sexually. However, nearly all tested fungi show signs of recent genetic recombination. 5. Two large phyla (Ascomycota and Basidiomycota) contain 95% of named species in kingdom Fungi and are informally called dikaryomycetes because their sexual life cycle has a unique dikaryotic stage. The remaining 5% of named species are divided between three phyla (Glomeromycota, Zygomycota, and Chytridiomycota) and are informally called coenomycetes because their hyphae lack the regular septation found in dikaryomycetes. 6. Kingdom Fungi excludes some organisms that traditionally are called fungi, and adds other organisms that were previously left out. New studies are changing classification within the kingdom.
3 20.1 FUNGI: FRIENDS AND FOES Everyone has met the fungi, for better or worse (Fig. 20.1). We all know about mushrooms and moldy food, but fungi are much more important than that. Many
- Spring '19
- partner, Zygomycetes, aseptate hypha