Fungi reproduce at a fast rate. This explains why mold quickly invades exposed food items like bread. Fungi replicate using different strategies that cut across sexual and asexual reproduction. Their unique methods and rate of reproduction set them apart from plants and animals.
Fungi reproduction has more depths than their replication. They play key roles in the ecosystem and human life which makes their reproduction significant.
In this article, I’ll discuss the different methods and processes of fungi reproduction, their classifications, and factors that affect the choice of reproduction type.
How do fungi reproduce sexually?
Sexual reproduction in fungi is a complex process. In typical plants and animals, individuals are differentiated into males and females with their respective reproductive organs and cells. However, this is not the case in the fungi kingdom.
Instead of reproductive cells, fungi have specialized reproductive structures. Identical structures from different individuals fuse to form a zygospore.
The zygospore is genetically different from its parent haploids. Also, it further undergoes a different physiological process to bear its offspring.
Sexual reproduction in fungi is divided into four different stages.
Plasmogamy
Plasmogamy is the first stage of sexual reproduction in fungi. It is the coming together of two protoplasts (two compatible haploid nuclei) without fusion. They form a dikaryon with two nuclei (of each mating type). This is the longest phase of sexual reproduction.
Karyogamy
Karyogamy is the second and last stage of fusion of the nuclei of two identical haploid eukaryotic cells. The haploid nuclei fuse and form a diploid nucleus called the zygote. The diploid nucleus contains two sets of chromosomes that come from the parents.
The zygote grows into a mature diploid zygomycete that enters the next step of meiosis.
Meiosis
The last stage of sexual reproduction in fungi is meiosis. This process takes place in the gametangia organs where gametes of different mating types are formed. Meiosis is a process of cell division that results in the formation of four daughter cells.
This process of cell division reduces the number of chromosomes to one set per cell, forming another set of haploid nuclei. These nuclei are incorporated into meiospores that are released into the environment.
How do fungi reproduce asexually?
Asexual reproduction is simpler, faster, and more efficient. Also, it is the more common form of reproduction in fungi. There are four methods of asexual reproduction in fungi. They are:
Budding
In budding, a new organism forms from a bud (an outgrowth) on the parent organism. The bud develops into a new organism but remains attached to the parent fungi until it matures. After maturity, the bud falls off and develops into an independent organism.
An example of fungi that reproduce using this method is yeast.
Fragmentation
Fragmentation is a method of asexual reproduction that involves the splitting of a new organism from the parent fungi. The parent mycelium splits into smaller pieces, and each piece can develop into an independent mycelium. This form of reproduction is typical of molds.
Fission
In fission, a parent fungal cell elongates and cleaves into two identical daughter nuclei. The process of cell division begins from the nucleus into the cytoplasm and the cell membrane to form two independent daughter cells.
This form of reproduction is seen in a species of unicellular yeast known as the fission yeast.
Spore formation
Some fungi produce asexual non-motile spores. These spores mature and develop into haploid individuals. The spores are carried by water or air to a different location where they develop into hyphae and an independent fungus if the conditions are favorable.
Fungi produce three different types of spores: sporangiospores, zoospores, blastospores, arthrospores, chlamydospores, and conidiospores.
Classification of fungi based on reproduction
Fungi can be classified into four phyla based on their methods of reproduction. They are:
Ascomycota
Phylum ascomycota or sac fungi produces sexual pores in a sac-like structure called the ascus. These fungi can also reproduce asexually by producing spores called conidia. This phylum comprises parasitic, saprophytic, and mutualistic species.
Basidiomycota
The club fungi make up the phylum Basidiomycota. These fungi can reproduce sexually or asexually, depending on the surrounding factors. They may produce sexual spores on a basidium or asexual conidia. Members of this phylum are mushrooms, smuts, and bracket fungi.
Zygomycota
The phylum zygomycota is also called the bread molds. This is the type of fungi you are very familiar with, the mold that grows on your bread loaves and chocolate bars.
Members of this phylum reproduce sexually by forming a thick-walled zygospore after the fusion of two gametangia. They can also reproduce asexually by forming non-motile sporangiospores inside a sporangium.
Chytridiomycota and Neocallimastigomycota
These fungi are different from the three phyla listed above. They have flagellated spores and reproduce asexually by forming zoospores that move by swimming with their flagella.
Unlike other types of fungi, members of these phyla rarely reproduce sexually. And when they do, it occurs through the formation of planogametic copulation.
Factors that affect reproduction in fungi
Some factors affect the choice of reproduction in fungi. These factors also influence the rate and success of replication. These factors are:
Environmental conditions
Changes in temperature, light intensity, humidity, and even the presence of certain chemicals in the surroundings of the fungi can change the choice of reproduction.
If a fungus naturally reproduces asexually and the environmental conditions become harsh, it would rather produce sexual spores, which can withstand harsh conditions better.
Availability of mate
Sexual reproduction in fungi requires mating mates. However, some species can reproduce without mates, and some require compatible mates. In the presence of a compatible mate, sexual reproduction will occur. Otherwise, the fungus will switch to asexual reproduction.
Nutrient availability
Nutrient abundance or deficiency can also trigger a change in the choice of reproduction a fungus employs.
When there is an abundance of nutrients, a fungus would reproduce sexually. But, in a scarcity or deficiency, it switches to sexual reproduction to produce offspring with enhanced adaptability.
Age of mycelia
Aged or stressed mycelia have a higher tendency to undergo sexual reproduction. They do this in a bid to produce offspring with new and improved genetic combinations that can withstand harsh conditions. Conversely, younger and healthier mycelia will reproduce asexually.
Which is the most preferred form of reproduction in fungi?
The preferred form of reproduction for a fungus that can carry out both forms of reproduction is asexual. Through this method, the fungi can produce many spores within a short time, unlike sexual reproduction.
Most fungi use sexual reproduction when the conditions become unfavorable and when they need to create more varied species.
FAQs
How frequently do fungi reproduce?
Fungi reproduce and spread quickly when the conditions are favorable. They use asexual reproduction to increase their population and use sexual reproduction to increase their genetic variation
What are imperfect fungi?
Imperfect fungi, fungi imperfect or deuteromycota refer to a group of fungi that are out known to reproduce asexually. They do not have a known sexual phase or possess the structures used to describe other fungi.
Some of this type of fungi live on land and some live in water. Regardless of the “imperfect” tag, these microorganisms can have a positive impact in several industries and human life. For instance, some species are useful in cheese ripening
How do lichens reproduce?
Lichens reproduce sexually and asexually. In sexual reproduction, the lichen releases spores through the air, and these spores can grow into new lichen under favorable conditions.
Asexually, fragments of the thallus separate and form a new lichen. These fragments can be taken to a different location by water, air, rain, or by the activities of creatures that live on the trees or rocks.
Conclusion
The method of reproduction a fungus carries out helps it to adapt to different environmental conditions and ecological niches. Also, the method of reproduction varies with the type of fungi.
Most fungi can reproduce both sexually and asexually, depending on the condition of their environment. Some types reproduce only asexually by budding or the formation of spores. Also, some types reproduce sexually through the fusion of identical haploids (+ and -) to form a zygospore.
Learn about the similarities and differences between algae and fungi.
Thanks for reading.