Fungi (plural of fungus) represents a diverse group of eukaryotic organisms that are classified under the kingdom with the same name. Some are unicellular, such as yeast, and may be considered both useful, as when used as baker’s yeast, or seen as harmful, as when seen on a child’s tongue as thrush. Other common fungi include some molds, mildews, symbiotic associations with algae called lichen, and mushrooms. The Shiitake and Portabella mushrooms you see in the produce section of your supermarket are edible fungi. They are also used in some antibiotics and are particularly useful in helping along the decaying process in organic matter.
Fungi seems to be everywhere we look. There are the fairy rings in your yard, the mildew on the grout of your bathroom tiles, and mushrooms and mold blanketing the forest floors. So how do these fungi proliferate so? Spores.
Spores are a special type of reproductive cell that may be either sexual or asexual. These microscopic cells are usually measured in mircons, or one millionth of a meter. Considering their size, its no surprise that some puffballs, a globular fungi that feed off of decaying trees, can disperse up to seven trillion spores when disturbed. These spores may “hibernate” until conditions are favorable and then germinate, producing mycelium. The mycelium consists of thread-like filaments called hyphae and make up the body of the fungus. The mycelium can produce fruiting bodies, such as mushroom caps, which will develop more spores. And the cycle repeats.
These spores move around their environment much like any seed. In some cases we move them purposefully ourselves, harvesting them for food, antibiotics (the first penicillin was derived from a mould), or to facilitate the production of beer and wine. In the wild, there are other mechanisms.
Since they are incredibly lightweight and small, a gentle wind can disperse millions of spores all around the forest floor. Spores carried by the wind are a concern to many immunologist due to the fact that they have been linked to allergies. Spores may also travel by water in streams or during a heavy rain. Wind is the most common vector by which the fungal spores are dispersed and leads to a more widespread distribution. Water will “weigh” the spore down and confine its travels to the immediate surrounding area. Animals and insects may also carry the spore to other locations, either by the spore sticking to its body or by ingesting the spore and then releasing it in another area. Spores have been shown to travel great distances, even between continents.
An easy way to see fungal dispersal in action is to put on some gloves and pick some mushrooms from around your neck of the woods. Find a safe place to work where there are no children or animals that could ingest the mushrooms. Then take a white sheet of paper and place the mushroom caps on the paper with the gills facing down. Cover the mushrooms with a large bowl and then remove the bowl the next morning. You will see the gill patterns on the paper. These are the spores that were dispersed overnight
