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 is formed from a protuberance or bud arising from the parent organism. In this reproduction, the bud formed in the parent organism either gets detached to form a new individual or remains attached by forming groups or colonies. As it is asexual reproduction, individuals formed by it are genetically and morphologically identical to their parents. It occurs mainly in a specialized area of parents, but in some species, it arises from any part of the parent’s body. It is also known as gemmation. Gemmation occurs in both unicellular and multicellular organisms. Organisms such as specific bacteria, yeast, Hydra, flatworm, jellyfish, etc., reproduce via this method.
Types of budding
It can be of two types. These include; external and internal budding
It is also known as exogenous gemmation. In this type, outgrowth or bud is formed 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 commonly occurs in Saccharomyces cerevisiae, and the symmetrical type is commonly found in Hydra, etc.
It is also known as endogenous gemmation. 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 of Gemmation
A few single-celled organisms (e.g., specific bacteria, yeast, protozoans, etc.) and many animals (e.g., hydra, jellyfish, flatworm, etc.) frequently reproduce by this method. Similarly, in horticulture and agriculture, the term refers to the grafting of a plant in which the bud of the plant is joined 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 process. 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 be propel to form 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 budding. 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 is also found 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 include; flatworms, polyps of jellyfish, polyps of sea anemones, etc.
Budding in plants
It is also one of the forms of vegetative reproduction. This occurs naturally or induced artificially in horticulture and agriculture. It is the process in which the bud of one plant grafts onto the another plant as both plants grow together. Mostly buds of one plant insert into the bark of the stem of another plant.
Different types of budding in plants include; T, patch, chip, ring, and flap budding.
This method is also known as shield budding. Vegetative propagation in which bud inserts into the shaped incision made in the rootstock. Examples include; oranges, roses, plums, and peaches.
This method involves a patch of bark with a bud being inserted into a similar depatched rootstock. Examples include; citrus, mango, rubber, walnut, etc.
This method involves a bud and a root inserted in a rootstock. Examples include grapes.
It involves bud and a bark ring from bud wood inserted into the rootstock. Examples include chincona.
It is a type of bud grafting in which bud inserts into the flap of bark lifted from the rootstock and is also known as forkert budding.
Advantages of Gemmation
- Under favorable conditions, one can obtain a large population.
- Only single parent needed
- It occurs in a short duration of time as no mating required.
- It is faster than sexual reproduction.
Disadvantages of Gemmation
- As identical offspring are produced, 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 the two mode of asexual reproduction include;
|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;
|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.|
- 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/genes12050661
- 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