Exploring Kingdom Fungi

• Kingdom Fungi is a diverse group of living organisms
• These notes outline the characteristics, structure, function, nutrition, reproduction, and classification of fungi

Kingdom Fungi Key Facts:

• Ontario produces roughly 50% of Canada's commercial mushrooms, making it the mushroom capital
• Fungi are more closely related to animals that to plants
• Includes mushrooms, molds, mildew, yeasts, truffles, and rusts
• Fungi cause 80% of all plant diseases
• The black truffle (Tuber melanosporum) is a species of fungus, prized as an expensive flavor in cooking
• Black truffles are located at the roots of oak trees with trained animals and cost $1500 per kilogram

Phylogeny

• Fungi are more closely related to animals than to plants
• Animal cells contain centrioles whereas fungal cells do not

Characteristics of Fungi

• Fungi consist of thread-like structures called hyphae
• Hyphae are covered by cell walls made of chitin
• Hyphae can have cross walls called septa, or exist as one multi-nucleated cell
• Cytoplasm flows continuously through hyphae, allowing the swift movement of materials
• Hyphae branch extensively, forming a mesh-like mass called a mycelium, which is used for feeding
• A mushroom represents the fruiting body of a fungus, an above-ground extension of mycelium
• Underground mycelia often work with plant roots in a symbiotic relationship as mycorrhizae

Nutrition

• Saprophytic heterotrophs (decomposers): break down dead organisms, for nutrition
• Some are parasitic: ringworm, athlete's foot
• Mycorrhizae: demonstrate a partnership between fungus and plant roots, in which the Plant provides food and Fungus enhances absorption of nutrients and water

Reproduction

• Capable of both Asexual and Sexual reproduction
• Asexual reproduction occurs through: budding, fragmentation, or spore production
• Sexual reproduction occurs through spore production
• Fungi can reproduce asexually: new fungi can grow from broken hyphae pieces, or from spores
• Fungi can reproduce sexually
• Opposites sexes of hyphae fuse to form a diploid
• The zygospore then produces haploid spores which are genetically unique, increasing genetic diversity

Classification

• Fungi are organized into 5 Phyla based on method of reprodution
• Phylum Zygomycota
• Phylum Ascomycota
• Phylum Basidiomycota
• Phylum Chytridiomycota
• Phylum Glomeromycota