Fungal reproduction is incredibly diverse, as are its species. This is one of the five kingdoms that is most diverse in terms of the characteristics of its organisms, and this is because they reproduce in two ways with different mechanisms. This entry will explain a little about how fungi reproduce.
fungi kingdom
Fungi are part of the domain Eukaryota and the kingdom Fungi, one of the five Kingdoms of living things commonly used in biology. More than 100.000 species have been recorded and described within this kingdom, so its classification encompasses several levels of the classification system (taxonomy) that many scientists have agreed upon over the years.
Everything has been an evolution, including biological studies, before living species were grouped into only three main kingdoms, the animal kingdom, the plant kingdom and the mineral kingdom and fungi were related to plants (so they entered the plant kingdom), however it was shown that they do not have autotrophic nutrition but rather feed on organic matter and transform it into energy and nutrients for them to continue living and reproducing.
Then they were related to animals but as they were studied it was shown that they have cell walls that are composed of chitin (this is something they share with plants), cell walls function as layers that resist natural forces to the that are exposed day by day, taking into account that fungi can be found in many types of environments, with a wide variety of conditions. In fact, taking into account their environment they are divided into:
- saprophytic fungi: These can arise from residues of other organisms, in fact they depend on them to live. They can be leaves of dead trees or plants, corpses of animals and people, excrement as well.
- Lichenized fungi: They come from a symbiosis between a fungus and an algae, a kind of yeast falls within this classification.
- Mycorrhizal fungi: Here too a symbiosis is produced but it is not with the algae but with the plants, these fungi benefit from the minerals and water from the roots of the plants from which they are born and they from them.
- Parasitic fungi: The parasites, unlike the previous ones, do not grant benefits to the organisms with which they make the symbiosis, in fact they damage them although they depend on them. Here the symbiosis is characterized by the fungus being the parasite and the other organism a host.
Another difference between fungi and plants is how they reproduce. Plants have stomata, produce flowers, sprout seeds, and from these seeds, more fungi emerge. Animals mate and sometimes reproduce asexually (in some species), while fungi reproduce by means of spores within sporangia. These spores can be produced through both sexual and asexual reproduction. Some plants and bacteria also produce spores.
Although the evolutionary history of this kingdom has been studied even more than that of the others, the Fungi kingdom does not have as much mention as the animal or plant kingdoms. Mycology is the science that is responsible for studying them and has been considered one of the most diverse and with the most extensive studies, this goes hand in hand with the number of species of fungi found over time.
In addition to that, it has many interesting characteristics in many more species than those seen in the other kingdoms, for example, the feeding or type of reproduction that fungi have, they function as main decomposers of the dead matter of beings from the other kingdoms and have a vital importance in the biogeochemical cycle.
How do mushrooms reproduce?
Fungal reproduction occurs primarily through spores. Spores are microscopic bodies formed in fungi by mitosis and can have their own characteristics depending on the type of fungus, thus giving rise to several types of spores:
- Ascospore: these are the ones that are produced in asci, which would be the ascomycete fungi
- basidiospore: these are the basidia, which would be the fungi of the basidiomycetes class
- conidium: these are asexual spores that are produced mostly in deuteromycete fungi
- Ecidospore: They occur in the puccinia species
- Sporengiospore: They are wives of the species of fungi belonging to the zygomycetes
- Glomerospore: Glomal fungi reproduce with this type of spores, they belong to the Zygomcota division.
- Oospores: The fungi that produce these spores are part of the oomycete group and are classified as pseudofungi.
- Teliospore: This type of spores, like the basidiospores, are part of the reproduction in basidiomycete fungi.
- Zygospore: These are seen in zygomycete fungi
- Zoospore: Spores of this type are produced by fungi classified within the Chytridiomycota group and the Opisthosporidia group.
After the spores are produced within the sporangia, they disperse to survive in any type of conditions in which the main fungus can be found, this dispersion can be done by the wind, by plants or even by animals, they can really be maintained for enough time while they get an ideal condition.
When the conditions are in favor of their germination, a hypha is produced that can grow up to 5 mm per second (this in the case of tropical fungi), when they are growing they are called mycelia.
Fungi can reproduce sexually, asexually, or even both ways in some species. These latter species alternate between the two depending on the conditions at the time of spore production, because sexual reproduction has some advantages while asexual reproduction has others that may be more beneficial for the fungus. The reproduction of these organisms is varied, just like the entire fungal kingdom.
In this sense, its reproduction can be generally differentiated into two phases: one perfect and one imperfect, or teleomorphic or anamorphic phase:
- Perfect phase: This is called teleomorph and is sexual, where there is a genetic variety, it is useful when the fungus seeks to survive and produces several organisms so that a new generation is created or more fungal diversity is created. This is also a little slower, something that works when the fungi are in a place where the environmental conditions vary.
- Imperfect phase: This is called anamorph and is asexual, where there is no genetic variety because the spore is produced by a fungus and its characteristics will be identical. This type of reproduction is faster than sexual reproduction and is common in those species of fungi that need to reproduce very quickly in another living being or in a large number of plants.
Sexual reproduction
Sexual reproduction can be defined as that where an organism is created that depends on two others, these combine their genetic material to create this third organism and thus share the material. It is a cell division that generally occurs in living beings of the Eukaryota domain. In this type of reproduction, twins (which are special cells) and even more cells are born.
In this sense, sexual reproduction in animals requires two organisms, two fungi in this case, to exchange progametangia so they can fuse (if compatible) and form another cell called a zygosporangium. Here, the fungi can be very different from their parents or they can share similar characteristics that allow them to be classified as order, family, genus, and species.
Sexual reproduction has several types of mechanisms in fungi, just as it can occur in the previous way, fungi can create gametes that are female or male within the gametangia. When these come into contact within this structure (one being male and the other female) a fusion occurs, this initial union is called plasmogamy and when the fusion is made a cell is created that has two sets of chromosomes.
The above is only seen in some species of fungi, in the species that are classified as true, reproduction forms a diploid zygote (with two sets of chromosomes) that does not resist for long until it becomes an adult fungus, they actually generate other spores for new fungi to arise, this is called meiosis and occurs when the zygote is inside a resistant spore.
At the beginning it was indicated that there are several forms of spores, these can have different sizes and the fungi that produce them can be of any type, it is because of this variety that there are different types of sexual reproduction of fungi based on that form of spores:
- When playback is by planogametes the fungus forms motile gametes that make contact with cytoplasm and then fuse.
- When playback is by gametangy an antheridium (which is what the male ones are called) and an oogonium (which corresponds to the female ones) are formed, they come into contact through a fertilization tube and the antheridium yields gametic nuclei to the oogonium.
- When one is given gametangial copulation the cells come into contact, form a zygote and this is protected by a spore within the gametangia.
- Sexual reproduction can also be seen with spermatization where the cells that form the fungi are very similar to human sperm, they differ in that they do not have a flagellum but when they reach the oogonium it fertilizes it.
- Finally, sexual reproduction by somatogamy It is characterized by the union of hyphae directly, which are generally vegetative. This is a reproduction that is observed in fungi with more complexity and formation than others, although the union is quite simple.
Asexual reproduction
Asexual reproduction in animals , humans, fungi, or any living being is based on the formation of another living being from one or more cells of a single parent organism; that is, another organism is not necessary for this type of reproduction to occur. It happens through mitotic processes or processes such as fission or cell division, where a parent cell fragments and divides into two or more daughter cells.
It loses its initial identity because it fragments and ceases to be the original organism, sponges have this type of reproduction and the cells divide by buds that are created within their body before separating. This is known as budding and it is the opposite of what plants do. Here the spores also grow in sporangia and are then released or dispersed to later germinate until they become a fungus identical to the one that originated it.
Asexual reproduction can take several forms:
- It may be through the mechanism of fragmentation of the mycelium where it is divided into several pieces from which an individual can emerge and from there they reproduce more quickly and in greater quantity.
- Another mechanism is gemmation which is a form of reproduction that fungi have in common with other organisms such as bacteria, here the fungus creates a yolk in which half of its genetic material and part of its cytoplasm are found.
- Reproduction can also occur through conidia: which is the production of asexual spores that are found in conidiophores, this can be done by budding or they can fragment to reproduce astrospores that, when they grow, form other fungi equal to the original. Here you can see conidiogenesis that can be thallic or blastic, they are two forms of asexual reproduction within this classification.
- The sporangia they are also part of another mechanism, within them the spores are housed that are asexual but these are mobile unlike those found in conidiophores. They can move to grow in another environment but remain within membranes.