Types of Fungi

Basidomycetes: Club Fungi Mushrooms are the most common club fungi. Others include rusts and smuts that harm crop plants. The visible mushroom is merely a fruiting body. The bulk of the organism is underground, a mat of hyphae (strands) called a mycellium that can be quite large. One example in Oregon covers 2200 acres (3 ½ square miles), to a depth of 3 feet, and it is at least 2400 years old.

Mushrooms Spores Mycelium

Mushroom Life Cycle Haploid hyphae meet and form a dikaryon: hyphal cells with 2 nuclei. After growth, the dikaryon sends up mushrooms as fruiting bodies. The 2 nuclei fuse in some of the mushroom cells, creating a diploid nucleus. The diploid nuclei undergo meiosis, resulting in new haploid cells. The haploid meiotic products turn into spores, which blow away and germinate into new hyphae.

Zygomycetes Zygomycetes form a diploid spore (think “zygote”) that undergoes meiosis after germination. Zygomycetes also have asexual, haploid spores. Bread mold is a common zygomycete. Another important zygomycete group is the mycchorrhyzae, fungi that infect the roots of most plants. These fungi have a symbiotic relationship with the plants: the fungi gather nutrients form the soil as an extension of the roots, and the plant supplies nutrients from photosynthesis.

Bread Mold Spores—reproduction Mycelium—absorbs nutrients (NOT roots)

Ascomycetes Ascomycetes are sac fungi: they produce spores in sacs. Truffles and morels are good examples of ascomycetes: they taste good! Penicillium, the mold that gave penicillin, the first antibiotic, is an ascomycete. Pennicillium also gives flavor to certain cheeses. Sac fungi also include some important single celled yeasts. Saccharomyces cerevesiae is used to make bread rise and also to ferment beer and wine. Candida albicans produces the common human yeast infections.

Yeast: unicellular fungi; used in making bread Ringworm and Athletes Foot: Parasites Lichens: composed of fungi and algae Example of symbiotic relationship—both benefit. Fungus provides moisture and algae provides food through photosynthesis.

Importance: 1. Beneficial a. Food—Mushrooms b. Yeast—Baking and brewing c. Cheeses—Bleu Cheese d. Penicillin—Antibiotic e. Cyclosporine—Drug used to prevent organ transplant rejection f. Decomposers—Recycle nutrients by breaking down bodies and waste of other organisms

2. Harmful: a. Mildew b. Human diseases—Ringworm and Athletes Foot c 2. Harmful: a. Mildew b. Human diseases—Ringworm and Athletes Foot c. Plant diseases—Mold, Powdery Mildew, Rusts