Reproduction: Fungi
Fungi reproduce asexually by one of two mechanisms, either by fragmentation of the colony, or by the formation of spores from specific structures on the colony. Fungi are composed of hyphae. Each cell in each hypha has the potential to become walled off from the rest of the fungus and on separation establish a new organism. This is analogous to asexual multiplication in bacteria.
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animation of hyphal fragmentation (18 Kb).
Fungi have a second mechanism for multiplication. You may see these on the fungi growing on the agar plates you expose to the environment. Fungi develop structures that produce cells (spores) that separate from the host. The structures either produce the spores in sacs or extrude them.
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animation showing the formation of conidia (14 Kb).
Sexual reproduction in all eukaryotes is essentially similar. Equivalent quantities of DNA from two different parents are combined to form the new offspring. I will leave the explanation to the discussion of meiosis. It is interesting to note that the mechanisms surrounding meiosis were first elucidated using fungi such as Neurospora and Aspergillus
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animation showing the process of meiosis (33 Kb).
The potential rate of reproduction in fungi is extremely high. One spore may form 106 spores on an agar plate within about 2 weeks under ideal nutrients, temperature and humidity. The spores would be formed following asexual processes.
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animation of asexual reproduction in fungi (108 Kb).
The rate of sexual reproduction is slower. The sexual phase of a bracket fungus is the bracket. Under ideal temperature, humidity and nutrients, one mature bracket has been recorded to release 108 spores per year.
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animation of spore dispersal by fungi (4 Kb).
Just imagine what it would mean if each of these spores formed a new colony?
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