Asexual reproduction is the process of producing offspring without the fusion of gametes. It occurs in many different forms. Vegetative propagation, fragmentation , regeneration, binary fission, and budding are some of the forms of asexual reproduction.
Budding refers to asexual reproduction in which a new offspring forms from a protuberance or bud arising from the parent organism. In this reproduction, the bud formed in the parent organism either detaches to form a new individual or remains attached by forming groups or colonies.
As it is asexual reproduction, individuals formed by this type of reproduction are genetically and morphologically identical to their parents. This sexual reproduction occurs mainly in a specialized area of parents, but in some species, it arises from any part of the parent’s body. Another term for this method is gemmation. This method occurs both in unicellular and multicellular organisms. Organisms such as specific bacteria, yeast, Hydra, flatworm, jellyfish, etc., reproduce via the gemmation method.
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Types of budding
Budding a type of asexual reproduction is of two types. These include; external and internal budding
External budding
Exogenous budding is another term for this type. In this type, outgrowth or bud formation occurs outside of the mother’s parent. Thus formed bud remains attached to their parents until they mature and, on maturation, detaches and acts as a new individual. It is either symmetrical or asymmetrical type. The asymmetrical type of budding commonly occurs in Saccharomyces cerevisiae, and the symmetrical type commonly occurs in Hydra, etc.
Internal budding
Endogenous budding is another term for this type. In this type, outgrowth or bud develops within the mother’s parents, also known as gemmule (mass of cell enclosed in an opaque envelope) that gives rise to offspring. This type occurs in sponges (Spongilla, Sycon) and also occurs in the parasite, i.e., Toxoplasma gondii.
Examples
A few single-celled organisms (e.g., specific bacteria, yeast, protozoans, etc.) and many animals (e.g., hydra, jellyfish, flatworm, etc.) frequently reproduce by budding. Similarly, in horticulture and agriculture, the term budding refers to the grafting of a plant in which the bud of the plant joins to the stem of another plant to produce the desired offspring.
Budding in yeast cell
Yeast is a single-celled eukaryotic microorganism that reproduces through this method of asexual reproduction. It generally occurs in nutrient-rich conditions. In this type of reproduction, a squashy zone appears in the cell wall of the mother cell through which buds bulge out. During this period, the nucleus of the mother cell undergoes mitotic division producing daughter nuclei; one of them will propel into the formed bud. Then constriction forms between the newly formed bud and the mother cell body. The newly formed buds grow and detach from the mother cell to form a new individual.
Budding in hydra
Hydra is a freshwater living creature that reproduces through this method of asexual reproduction. In this process, a bud develops due to constant mitotic cell division at a particular site. These buds then develop into tiny structures. When fully developed, it separates from the parent body and becomes a new individual.
Budding in animals
Though it is common in yeast and bacteria, it also occurs in certain animals too. In this process, the parent organism produces bud that matures to produce a new individual. Animals that reproduce through this method of asexual reproduction include; flatworms, polyps of jellyfish, polyps of sea anemones, etc.
Budding in plants
It is also one of the forms of vegetative reproduction. This type of asexual reproduction can occur naturally or induced artificially in horticulture and agriculture. It is defined as the process in which the bud of one plant is grafted into another plant as both plants grow together. Mostly buds of one plant are inserted into the bark of the stem of another plant. Different types of budding in plants include; T-, patch-, chip, ring-, and flap budding.
T-budding
Shield budding is another for this method. Vegetative propagation in which bud insertion occurs into the shaped incision made in the rootstock. Examples include; oranges, roses, plums, and peaches.
Patch budding
This method involves a patch of bark with a bud insertion into a similar depatched rootstock. Examples include; citrus, mango, rubber, walnut, etc.
Chip budding
This method involves a bud and a root inserted in a rootstock. Examples include grapes.
Ring budding
It involves bud and a bark ring from bud wood inserted into the rootstock. Examples include chincona.
Flap budding
It is a type of bud grafting in which bud insertion occurs into the flap of bark lifted from the rootstock. Forkert budding is another term applicable for this type.
Advantages
- Under favorable conditions, this method can produce a large population of offspring.
- Only a single parent needed for this method.
- This type of asexual reproduction occurs in a short duration of time as there is no requirement of mating.
- It is faster than sexual reproduction.
Disadvantages
- As there is production of identical offspring, they contribute less to biodiversity.
- Being genetically identical, any stress in the environment can affect the whole organism.
Differences between budding and binary fission
Budding and binary fission are two types of asexual reproduction that give rise to genetically identical offspring. Differences between these two methods of asexual reproduction include:
| Binary fission | Budding |
| It is the process in which two daughter cells are produced from single mother cells. | It is the process in which offspring is produced from the mother cell from bud-like outgrowth. |
| No mother cell is identified as it divides into two daughter cells. | The parent organism remains the same even after the detachment of the bud. |
| In this process, the division of cytoplasm is even | In this process, the division of cytoplasm is unequal. |
| It occurs mostly in prokaryotes | It occurs mostly in eukaryotes |
Differences between budding and fragmentation
Budding and fragmentation are also the types of asexual reproduction that give rise to genetically identical offsprings. However, differences exist between these types, which include:
| Budding | Fragmentation |
| It is defined as the process in which offspring are produced through bud-like projection developed within the parent body. | It is defined as the process in which offspring are produced from the fragments of the parent body. |
| It occurs both in unicellular and multicellular organisms. | It occurs in multicellular organisms. |
| Buds become mature when attached to their parents and then they get detached from them. | Fragments formed from the parent’s body mature after separating from the parent. |
| In this process, single-daughter individuals are produced. | In this process, several daughter individuals are produced. |
| Examples include; Sea anemone, yeast, etc. | Examples include; Planaria, fungi, lichens, etc. |
References
- Isaksson H, Conlin PL, Kerr B, Ratcliff WC, Libby E. The consequences of budding versus binary fission on adaptation and aging in primitive multicellularity. MDPI, 2021 12(5):661. DOI: 10.3390/genes1205066
- Jahangeer M, Mahmood Z, Mashooq A, Mehmood R, Munir N, Tahir IM, et a. Yeast cells secondary metabolites and their industrial applications; a review. Pakistan Journal of Medical and Biological Sciences, 2019. 2(1):62-67. https://www.researchgate.net/publication/337482316_Yeast_cells_secondary_metabolities_and_their_industrial_applications_a_review
