Information and Science Projects
What is a mushroom? It is the fruit (like an apple) of the mushroom "plant" and contain mushroom "seeds" called spores. The body of the mushroom in called mycelium and its individual parts are microscopic. Since the body of the mushroom is usually dispersed over a relatively large area it is rarely noticed. In nature some species of mushrooms may have a body that spreads over hundreds of square miles!
Mushrooms are fungi, and are usually placed in a Kingdom of there own apart from plants and animals. Mushrooms contain no chlorophyll and most are considered saprophytes. That is, they obtain their nutrition from
metabolizing non living organic matter. This means they break down and "eat" dead plants, like your compost pile does.
The body of the mushroom stores nutrients and other essential compounds, and when enough material is stored and the conditions are right they start to fruit - produce mushrooms.
Mushrooming up over night? If the body is spread out and microscopic, how do mushrooms grow so quickly? There are two basic reasons: 1) Since they store up compounds between fruiting and most fruit once a year, they have a lot of reserve available to support the mushroom. 2) Mushrooms develop differently than plants or animals do. Plants and animals grow through cell division - to get bigger they have to produce more cells. Cell division is relatively slow and requires a lot of energy. They mushroom body also grows by cell division. However, the mushroom fruit does not grow by cell division. Just about as soon as it starts to develop, a mushroom has almost the same number of cells that the mature mushroom will have. The mushroom increases in size through cell ENLARGEMENT! This means that the cells can balloon up very rapidly. Very little energy is required, basically the cells just enlarge with water. So a mushroom can increase in size as fast as water can be pumped into its cells. Almost overnight a mushroom can go from a pin head to a large mushroom.
Mushrooms need water for their fruit to "grow". That is why a saucer and a humidity tent is enclosed with the Mushroom Pot.
Mushrooms have no skin so they can lose water to the atmosphere very easily. That is why they grow in high humidity (lots of water vapor in the air) conditions. If the humidity is too low the cells lose water faster than it can be pumped in and the immature mushroom dries up and dies.
Mushrooms love all the water they can get? NO! Mushrooms need to breath just like humans do, except they do not have lungs. Mushroom cells exchange gases directly with the atmosphere. If the body of the mushroom is submerged in water it is comparable to drowning. No oxygen can be exchanged, anaerobic bacteria (bacteria which do not need oxygen to thrive) build up, and the mushroom is choked to death.
It is almost the same with the mushroom fruit. If it is too dry they lose too much water and desiccate. However, if it is too wet - the humidity is too high - the excess water prevents any gas exchange and the developing mushroom chokes off.
Things you can watch and do with Mushrooms
A. Growth rates.
Like most organisms without thermal regulation (they can not control nor maintain their body temperature), mushrooms grow faster when it is warmer. Try measuring the growth rates of the same variety of mushrooms in a Mushroom Pot at different temperatures. The Sonoma Brown Mushroom PotTM produces a good mushroom to work with.
Once the pinheads (young mushrooms that look like a fat white pencil tip) form, you could measure the length of the young mushroom every 4 or 8 hours. If you measured growth rates at 60 F, 70 F, and 80 F would find a marked difference in growth rates. If the temperature is too low, the mushroom will grow very slowly or not at all. If the temperature is too high, most likely the mushroom will die.
B. Spore Prints.A mushroom produces spores instead of seeds. The spore are produced on the gills you can see on the underside of the mushroom. These spores are microscopic and can only be seen under a microscope. However, each mushroom produces hundreds of thousands of spores, and this mass of spores is easy to see.
Pick a large mushroom off your Mushroom PotTM and place it gills down it on a dark piece of paper. Keep it at room temperature in a low humidity area. If the mushroom is very mature you may see a "spore print" of the gills in an hour or so. It may take a less mature mushroom several hours or overnight to produce this print. Each line you see is made up of mounds of microscopic spores.
Do Mushrooms Really Grow by Cell Enlargement?
With a microscope and a little work and fine motor coordination you can check to see if mushrooms really grow by cell enlargement.
Take a sample of the mushroom as soon as the pin head is visible. Section as thinly as possible with a brand new razor blade, stain you section and measure the cell diameter under a microscope.
As the mushroom grows, take sections from the stalk.
What you need:
Mushroom Growth Kit
Microscope slides & cover slips.
Very sharp razor blade.
Basic supplies for preparing material for microscopy.
"Stains" to try:
1. 3% KOH (potassium hydroxide) or 5-10% NH4OH (ammonium hydroxide)
2. Cotton Blue (Amman's Solution; Aniline Blue)
3. Crestyl Blue (0.5 - 1.0% aqueous solution)
4.Methylene Blue (1% aqueous solution)
Educator's Mushroom Growth Kits
need to bring fungi into your classroom.
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