All fungi reproduce using spores, which are more fragile than seeds but far easier to produce

Friday, March 14, 2014 by: David Gutierrez, staff writer
Tags: fungi, plant reproduction, spores

(NaturalNews) Like nearly every species of fungus, primitive plants reproduce by means of structures known as "spores" rather than the seeds we are more familiar with. These plants, including mosses and ferns, are much more similar to the ancestral plants that dominated the land before the evolution of seeds. Yet, in spite of the fact that seed-bearing plants have become so much more successful and have overtaken the earth, spores provide enough key advantages over seeds that these primitive plants continue to thrive and flourish in many parts of the world.

In biological terms, a spore is defined as a usually single-celled reproductive structure that possesses the ability to develop into a new organism, either on its own or through combination with another spore. This means that pollen is technically a specialized type of spore that combines with another specialized (female) spore to produce a seed. More colloquially, however, spores and seeds are considered separate reproductive strategies.

The advantages of seeds over the more primitive spores are fairly obvious: Seeds possess a hard coating that protects the embryonic plant from predation and the elements. In addition, seeds contain a fairly large quantity of food to help jump-start the young plant. This combination allows seeds to remain dormant for long periods of time until conditions are most favorable for growth and then sprout fairly quickly. In contrast, spores are easily destroyed and die quickly unless they are dispersed immediately into favorable conditions that include large amounts of water. This is why spore-bearing plants are almost unheard of in deserts (although certain varieties of fungus are hardier).

But this main advantage of seeds is also their weakness: That hard coating and extra food storage are very energetically expensive to produce. In contrast, a spore-bearing plant or fungus can produce literally millions of spores at very minimal energetic and nutritional costs. When you can produce that many spores, it doesn't particularly matter that the vast majority of them will die without ever producing a new organism.

Like seeds, spores are dispersed by a wide variety of strategies. The most common method of dispersal is through explosive discharge, either in a cloud or in the form of liquid droplets. Wind dispersal is also very common, and insect dispersal has also been documented.

Sources:

http://www.gardenguides.com