How do spores dispersed

However, their flagella do play a role in finding food. Flagellated spores are usually chemotaxic and will swim towards a chemical source. It is difficult to know where to put some mechanisms of dispersal.

There are actually more than one mechanism involved in the group of fungi known as the bird's nest fungi Fig. The common name is due to the strong resemblance that the fruiting body has with a birds nest. Prior to , they were thought to be flowering plants and the eggs, which contains the spores of the fungus, were thought to be the seeds of the plant. The actual dispersal mechanism of this fungus was not discovered until the 's by Dr.

Harold Brodie, a mycologist that would devote his career on studying this group of fungi. How Dr. Brodie determined the mechanism is an interesting story. However, before telling his story, let's look at the actual fruiting body of the bird's nest fungus. The 'eggs' that contain the spores are called peridioles. There are usually several peridioles per nest attached to the inside by means of a slender connection that is folded up called a funiculus. If we moisten a peridiole and pull the funiculus out, it may stretch up to 6 to 8 inches and at its base is a stick area, the hapteron that will adhere to any surface that it touches.

Before Dr. Brodie determined the mechanism, mycologists believed that the peridioles must have been shot into the air by some explosive force generated by the fungus itself since such of mechanisms are known to occur in some groups of fungi. However, long observations failed to detect any such explosive mechanism.

Brodie determined that the nest was so constructed that when a raindrop splashes into the nest, the force will eject the peridiole out of the nest up to a distance of feet. The force of ejection causes the funiculus to unwind and if the now wet and sticky hapteron comes in contact with any object as it flies through the air, it will stick to that object. Once attached the cord stretches and winds around the object. This all takes place very quickly. The peridiole is now in contact with a substrate where it can grow or it is in a position where it may be eaten by an animal.

Once in the animal, the peridiole can pass through the digestive system unharmed and grow on the dung pad. The most interesting dispersal mechanism can be found in the group of fungi that are commonly referred to as stinkhorns because of their unpleasant odor. These fungi produce their spores in a usually liver-brown slime, which is on top of a colorful part of the fruitbody.

When the spores are mature and exposed to the external environment, the odor of the spores will attract flies that will eat up the slime and spores thereby dispersing the fungus Figures. Another mechanism that is also very interesting that involves insect was discovered during the 's by Dr.

Barbara Roy, now at the University of Oregon. She discovered that a plant pathogen, Puccinia monoica induces the host, usually a species of the genus Arabis , to produce a " pseudoflower ". The pseudoflower is actually a modification of the leaves that mimics the appearance of the flower and attracts insect pollinators that have come to pollinate the pseudoflower.

Instead what occurs is that the insect completes the sexual cycle of the fungus. An easy to read article and a nice picture may be found here. Even on what looks like a windless day, there are always slight breezes. While a human may not feel them, they are usually strong enough to be felt by a spore that is only about a hundredth of a millimetre long. These micro-breezes may pick up the spore and carry it higher into the air and away from the parent mushroom. The spore may come to rest a metre or a kilometre or even further away from the mushroom.

It may come to rest on a grass blade, be eaten by a kangaroo that then moves away a few more kilometres and deposits it in a dropping. Basidiomycetes with similar mechanisms are the boletes , polypores , paint fungi , stereoid fungi , coral fungi and jelly fungi. A basidiomycete with a very different active method of spore dispersal is the Cannonball Fungus Sphaerobolus stellatus. The "egg" inside the two millimetre diameter cup contains a mass of spores and is forcible flicked out of the cup.

In a cup fungus the surface of the cup is lined with the spore-producing asci. As the spores in an ascus are maturing, fluid pressure builds up in the ascus. At maturity, the pressure is sufficient to force the spores out through the top of the ascus. In some species of cup fungi there is a little lid at the top of the ascus which is forced open to allow the spores out.

In others the tip of the ascus ruptures more irregularly. The spores may be shot several centimetres up into the air and, as in the case of the mushroom, air currents carry the spores further afield. From the structure of a cup fungus, you will realise that many asci can simultaneously shoot their spores. Often when you pick up fresh cup fungi the mechanical disturbance of picking up a specimen is enough to jolt thousands of mature asci into releasing their spores and, if you are attentive, you will see a small cloud of spores arising from the fungal surface.

As well as the simple cup fungi, the "compound" or "distorted" cup fungi such as Cyttaria , Morchella and Leotia release their spores in the same way. Many, but by no means all, of the flask fungi release their spores actively. Flask fungi differ fundamentally from the cup fungi. In the latter the asci line the surface of an open cup or disk but in the flask fungi the asci are contained within a chamber that has only a narrow opening at the top.

So there is no mass firing of asci. Instead, when an ascus is mature its tip extends to the opening, shoots out its spores and then collapses back into the chamber. Then another ascus can have its turn and so on. Spore Dispersal. Most fungi rely on gravity to carry their spores down and into air currents which will then carry them away to other places.

Gill fungi , boletes and polypores all have their spore producing surfaces on the undersurface of the fruiting bodies, so that the spores drop out into air currents below.