Offsets
Encyclopedia
In botany
and horticulture
Offset is a term used to describe a small virtually complete daughter plant that has been naturally asexually produced on the mother plant
. They are clone
s (e.g."hens and chicks"), meaning that they are genetically identical to the mother plant. In the plant nursery
business and gardens they are detached and grown on in order to produce new plants. This is a cheap and simple process for those plants which readily produce offsets as it does not usually require specialist materials and equipment.
s or homologous
structures differentiate into a new plant with the ability to become self-sustaining. This is particularly common in species that develop underground storage organs, such as bulbs, corms and tubers. Tulip
s and lilies are examples of plants, which display offset characteristics by forming cormlets around the original mother corm.
, thus seeking identical copies of parent plant, various cloning techniques (asexual reproduction
) are used. Offsets is a natural means by which plants may be cloned.
In contrast, when propagating plants to create new cultivars, sexual reproduction
through pollination is used to create seed
s. The recombination
of genes gives rise to offspring plant with similar but distinct offspring genome.
Botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...
and horticulture
Horticulture
Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...
Offset is a term used to describe a small virtually complete daughter plant that has been naturally asexually produced on the mother plant
Mother plant
A Mother plant is a plant grown for the purpose of taking cuttings or offsets in order to grow more quantity of the same plant....
. They are clone
Cloning
Cloning in biology is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or...
s (e.g."hens and chicks"), meaning that they are genetically identical to the mother plant. In the plant nursery
Nursery (horticulture)
A nursery is a place where plants are propagated and grown to usable size. They include retail nurseries which sell to the general public, wholesale nurseries which sell only to businesses such as other nurseries and to commercial gardeners, and private nurseries which supply the needs of...
business and gardens they are detached and grown on in order to produce new plants. This is a cheap and simple process for those plants which readily produce offsets as it does not usually require specialist materials and equipment.
Botany of Offsets
Offsets form when meristem regions of plants, such as axillary budAxillary bud
The axillary bud is an embryonic shoot which lies at the junction of the stem and petiole of a plant.As the apical meristem grows and forms leaves, a region of meristematic cells are left behind at the node between the stem and the leaf. These axillary buds are usually dormant, inibited by auxin...
s or homologous
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
structures differentiate into a new plant with the ability to become self-sustaining. This is particularly common in species that develop underground storage organs, such as bulbs, corms and tubers. Tulip
Tulip
The tulip is a perennial, bulbous plant with showy flowers in the genus Tulipa, which comprises 109 species and belongs to the family Liliaceae. The genus's native range extends from as far west as Southern Europe, North Africa, Anatolia, and Iran to the Northwest of China. The tulip's centre of...
s and lilies are examples of plants, which display offset characteristics by forming cormlets around the original mother corm.
Purpose
When propagating plants to increase a stock of a cultivarCultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
, thus seeking identical copies of parent plant, various cloning techniques (asexual reproduction
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
) are used. Offsets is a natural means by which plants may be cloned.
In contrast, when propagating plants to create new cultivars, sexual reproduction
Sexual reproduction
Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms. There are two main processes during sexual reproduction; they are: meiosis, involving the halving of the number of chromosomes; and fertilization, involving the fusion of two gametes and the...
through pollination is used to create seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s. The recombination
Genetic recombination
Genetic recombination is a process by which a molecule of nucleic acid is broken and then joined to a different one. Recombination can occur between similar molecules of DNA, as in homologous recombination, or dissimilar molecules, as in non-homologous end joining. Recombination is a common method...
of genes gives rise to offspring plant with similar but distinct offspring genome.