Growth and Reproduction
Fungi reproduce by releasing spores into the environment. Spores are produced either sexually or asexually and are carried by wind, water, and organismal vectors throughout the environment. If a spore lands in a moist place that contains food it will germinate to produce mycelia. Thus spores function in the dispersal and reproduction of fungi (Campbell, 618).
Gilled mushrooms produce millions of spores on the exterior of microscopic club-shaped cells called basidia (Arora, 4) which line the gills (Arora, 5). As the spores are discharged they are carried away by wind currents to different localities. Those that land in favorable environments are likely to germinate. As a spore germinates it sends out a germ tube that subsequently branches to form many threadlike cells called hyphae (Arora, 5). The hyphae spread throughout the soil or woody substrate absorbing nutrients through their cell walls (Barron, 26). If two spores of different but compatible strains fuse the resulting hyphae will contain the nuclei of each parent strain. The resultant hyphae grow rapidly forming an intricate network of filaments called the mycelium (Arora, 5). Before mating occurs in sexually reproducing fungi, each individual communicates with the other by means of chemical pheromones (Tree of Life, http://tolweb.org/tree?group=fungi).
When conditions are favorable (for most species damp and cool) some hyphae form bundled knots of tissue that develops over time into fruiting bodies. In the early stages of development fruiting bodies are referred to as buttons. As buttons they have a cap and stalk but the cap has not expanded. Over time the stalk elongates pushing the cap upward above the ground or other substrate in which it is growing. To finish, the cap expands breaking the veil (if present) thereby exposing the gills (Arora, 5). The gills that hang down on the underside of the mushroom’s cap produce another generation of spores that are eventually carried away by wind to new sites to begin the cycle anew (Barron, 26).
In addition to serving as a mechanism for dispersal/reproduction some spores function as resistant cells that allow the fungus to survive periods of time when environmental conditions are not suitable for growth (Tree of Life, http://tolweb.org/tree?group=fungi).
For a more detailed look at reproduction click on one of the following links: Basidiomycetes or Ascomycetes
Works Cited
Arora, David. Mushrooms Demystified. 2nd ed. Berkley, Ten Speed Press, 1986.
Barron, George. Mushrooms of Northeast
North America. Edmonton: Lone Pine,
1999.
Campbell, Neil A. Biology. 4th ed. Menlo Park: The Benjamin/Cummings Publishing
Company, 1996.
Tree of Life Web Project. 2006. The University of Arizona College of Agriculture and
Life Sciences and The University of Arizona Library. 21 April 2006.
<http://tolweb.org/tree/>