Plant propagation

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Gentian seedlings in a plant nursery Gentiana punctata seedlings (13900812284).jpg
Gentian seedlings in a plant nursery

Plant propagation is the process by which new plants grow from various sources, including seeds, cuttings, and other plant parts. Plant propagation can refer to both man-made or natural dispersal of seeds.

Contents

Propagation typically occurs as a step in the overall cycle of plant growth. For seeds, it happens after ripening and dispersal; for vegetative parts, it happens after detachment or pruning; for asexually-reproducing plants, such as strawberry, it happens as the new plant develops from existing parts. [1] Plant propagation can be divided into four basic types: sexual, asexual (vegetative), layering, and grafting.

Countless plants are propagated each day in horticulture and agriculture. The materials commonly used for plant propagation are seeds and cuttings.

The use of plant propagation has become increasingly more popular for medical plant breeding. Due to the large amount of the world that utilizes traditional medicine which includes the use of medicinal plants it has become very important to utilize the use of plant propagation. This also has to do with the herbal medicine community, which is becoming more popular. [2] The use of plant propagation is also important in the production of food production. Taking in to account the dietary change each year the world is constantly changing and needing more and more production to occur. Plant propagation has become an important role in our food sources. [3]

Sexual propagation

One way to germinate an avocado seed GrowingAvocadoFromSeed.JPG
One way to germinate an avocado seed

Seeds and spores can be used for reproduction (e.g. sowing). Seeds are typically produced from sexual reproduction within a species because genetic recombination has occurred. A plant grown from seeds may have different characteristics from its parents. Some species produce seeds that require special conditions to germinate, such as cold treatment. The seeds of many Australian plants and plants from southern Africa and the American west require smoke or fire to germinate. Some plant species, including many trees, do not produce seeds until they reach maturity, which may take many years. Seeds can be difficult to acquire and some plants do not produce seed at all. Some plants (like certain [4] plants modified using genetic use restriction technology) may produce seed, but not a fertile seed. [5] In certain cases, this is done to prevent the accidental spreading of these plants, for example by birds and other animals.

Asexual propagation

Rose cuttings under plastic bottle greenhouse Rose cuttings with plastic bottle greenhouse.JPG
Rose cuttings under plastic bottle greenhouse

Plants have a number of mechanisms for asexual or vegetative reproduction. Some of these have been taken advantage of by horticulturists and to multiply or clone plants rapidly. Humans may utilize these processes as propagation methods, such as tissue culture and grafting. [6] Plants are produced using material from a single parent and as such, there is no exchange of genetic material, therefore vegetative propagation methods almost always produce plants that are identical to the parent. Vegetative reproduction uses plant parts such as roots, stems, and leaves.

In some plants, seeds can be produced without fertilization and the seeds contain only the genetic material of the parent plant. Therefore, propagation via asexual seeds or apomixis is asexual reproduction but not vegetative propagation.

Softwood stem cuttings rooting in a controlled environment Cuttings greenhouse.jpg
Softwood stem cuttings rooting in a controlled environment

Techniques for vegetative propagation include:

Heated propagator

Electric propagator, filled with pepper plant seedlings, in front of a house window. ElectricPropagator.JPG
Electric propagator, filled with pepper plant seedlings, in front of a house window.

A heated propagator is a horticultural device to maintain a warm and damp environment for seeds and cuttings to grow in. They generally provide bottom heat (maintained at a particular temperature) and high humidity, which is essential in successful seed germination and in helping cuttings to take root. In colder climates they are sometimes used for plants like peppers and sweet peas which need warmer environments (about 15°C, for the plants listed) in order to germinate. If excessive condensation forms on the inside of the lid, the gardener can open the ventilating holes to regulate the temperature a little.

Non-electric propagators (mainly a seed tray and a clear plastic lid) are a lot cheaper to purchase than a heated propagator, but without the constant regulated warmth and bottom heat provided by a heated propagator, growth of seedlings tends to be slower and less consistent (with increased risk of seeds failing to germinate). [7] [8]

Seed propagation mat

An electric seed-propagation mat is a heated rubber mat covered by a metal cage that is used in gardening. The mats are made so that planters containing seedlings can be placed on top of the metal cage without the risk of starting a fire. Another example is a seedling heat mat, multiple layers of durable, water resistant plastic material with insulated heating coils embedded inside (similar to underfloor heating systems, but with rubber mat instead of flooring). [9] In extreme cold, gardeners place a loose plastic cover over the planters/mats which creates a sort of miniature greenhouse. The constant and predictable heat allows people to raise seedlings in the winter months when the weather is generally too cold for seedlings to survive naturally outside. When combined with a lighting system, many plants can be grown indoors using these mats. [10] This can increase the variety of plants that a gardener can use.

See also

Related Research Articles

<span class="mw-page-title-main">Fruit tree propagation</span> Usually carried out vegetatively by grafting or budding a desired variety onto a suitable rootstock

Fruit tree propagation is usually carried out vegetatively (non-sexually) by grafting or budding a desired variety onto a suitable rootstock.

<span class="mw-page-title-main">Cultivar</span> Plant or grouping of plants selected for desirable characteristics

A cultivar is a kind of cultivated plant that people have selected for desired traits and which retains those traits when propagated. Methods used to propagate cultivars include division, root and stem cuttings, offsets, grafting, tissue culture, or carefully controlled seed production. Most cultivars arise from purposeful human manipulation, but some originate from wild plants that have distinctive characteristics. Cultivar names are chosen according to rules of the International Code of Nomenclature for Cultivated Plants (ICNCP), and not all cultivated plants qualify as cultivars. Horticulturists generally believe the word cultivar was coined as a term meaning "cultivated variety".

<span class="mw-page-title-main">Horticulture</span> Small-scale cultivation of plants

Horticulture is the cultivation of plants in gardens or greenhouses, as opposed to the field-scale production of crops characteristic of agriculture. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and non-food crops such as grass and ornamental trees and plants. It also includes plant conservation, landscape restoration, landscape and garden design, construction, and maintenance, and arboriculture, ornamental trees and lawns.

<span class="mw-page-title-main">Vegetative reproduction</span> Asexual method of reproduction in plants

Vegetative reproduction is any form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or specialized reproductive structures, which are sometimes called vegetative propagules.

<i>Bauhinia <span style="font-style:normal;">×</span> blakeana</i> Species of legume

Bauhinia × blakeana, commonly called the Hong Kong orchid tree, is a hybrid leguminous tree of the genus Bauhinia. It has large thick leaves and striking purplish red flowers. The fragrant, orchid-like flowers are usually 10 to 15 centimetres across, and bloom from early November to the end of March. Although now cultivated in many areas, it originated in Hong Kong in 1880 and apparently all of the cultivated trees derive from one cultivated at the Hong Kong Botanical Gardens and widely planted in Hong Kong starting in 1914. It is referred to as bauhinia in non-scientific literature though this is the name of the genus. It is sometimes called the Hong Kong orchid. In Hong Kong, it is most commonly referred to by its Chinese name of 洋紫荊 (yèuhng jígīng).

<span class="mw-page-title-main">Waratah</span> Genus of plants in the family Proteaceae from southeastern Australia

Waratah (Telopea) is an Australian-endemic genus of five species of large shrubs or small trees, native to the southeastern parts of Australia. The best-known species in this genus is Telopea speciosissima, which has bright red flowers and is the New South Wales (NSW) state emblem. The waratah is a member of the family Proteaceae, flowering plants distributed in the Southern Hemisphere. The key diagnostic feature of Proteaceae is the inflorescence, which is often very large, brightly coloured and showy, consisting of many small flowers densely packed into a compact head or spike. Species of waratah boast such inflorescences ranging from 6–15 cm in diameter with a basal ring of coloured bracts. The leaves are spirally arranged, 10–20 cm long and 2–3 cm broad with entire or serrated margins. The name waratah comes from the Eora Aboriginal people, the pre-European inhabitants of the Sydney area.

<span class="mw-page-title-main">Cutting (plant)</span> Method of propagating plants

A plant cutting is a piece of a plant that is used in horticulture for vegetative (asexual) propagation. A piece of the stem or root of the source plant is placed in a suitable medium such as moist soil. If the conditions are suitable, the plant piece will begin to grow as a new plant independent of the parent, a process known as striking. A stem cutting produces new roots, and a root cutting produces new stems. Some plants can be grown from leaf pieces, called leaf cuttings, which produce both stems and roots. The scions used in grafting are also called cuttings.

<i>Canarium ovatum</i> Species of flowering plant

Canarium ovatum, the pili, is a species of tropical tree belonging to the genus Canarium. It is one of approximately 600 species in the family Burseraceae. C. ovatum are native to the Philippines. They are commercially cultivated in the Philippines for their edible nuts and is believed to be indigenous to that country. The fruit and tree are often vulgarized with the umbrella term of "Java almond" which mixes multiple species of the same genus, Canarium.

Plant breeders use different methods depending on the mode of reproduction of crops, which include:

<i>Malus sieversii</i> Species of plant

Malus sieversii is a wild apple native to the mountains of Central Asia in southern Kazakhstan. It has recently been shown to be the primary ancestor of most cultivars of the domesticated apple. It was first described as Pyrus sieversii due to its similarities with pears in 1833 by Carl Friedrich von Ledebour, a German naturalist who saw them growing in the Altai Mountains.

<i>Leucadendron</i> Genus of flowering plants in the family Proteaceae, endemic to South Africa

Leucadendron is a genus of about 80 species of flowering plants in the family Proteaceae, endemic to the Cape Provinces and KwaZulu-Natal in South Africa, where they are a prominent part of the fynbos ecoregion and vegetation type.

<span class="mw-page-title-main">Basal shoot</span> Shoot growing from an adventitious bud

Basal shoots, root sprouts, adventitious shoots, and suckers are words for various kinds of shoots that grow from adventitious buds on the base of a tree or shrub, or from adventitious buds on its roots. Shoots that grow from buds on the base of a tree or shrub are called basal shoots; these are distinguished from shoots that grow from adventitious buds on the roots of a tree or shrub, which may be called root sprouts or suckers. A plant that produces root sprouts or runners is described as surculose. Water sprouts produced by adventitious buds may occur on the above-ground stem, branches or both of trees and shrubs. Suckers are shoots arising underground from the roots some distance from the base of a tree or shrub.

Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur.

<span class="mw-page-title-main">Grafting</span> Horticultural technique of joining plant tissues to grow together

Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion while the lower part is called the rootstock. The success of this joining requires that the vascular tissues grow together. The natural equivalent of this process is inosculation. The technique is most commonly used in asexual propagation of commercially grown plants for the horticultural and agricultural trades. The scion is typically joined to the rootstock at the soil line; however, top work grafting may occur far above this line, leaving an understock consisting of the lower part of the trunk and the root system.

<i>Asclepias speciosa</i> Species of flowering plant

Asclepias speciosa is a milky-sapped perennial plant in the dogbane family (Apocynaceae), known commonly as the showy milkweed and is found in the western half of North America.

<span class="mw-page-title-main">Propagation of Christmas trees</span> Agricultural practice

The Propagation of Christmas trees is the series of procedures carried out to grow new Christmas trees.

Botany is a natural science concerned with the study of plants.The main branches of botany(also referred to as "plant science") are commonly divided into three groups: core topics, concerned with the study of the fundamental natural phenomena and processes of plant life, the classification and description of plant diversity; applied topics which study the ways in which plants may be used for economic benefit in horticulture, agriculture and forestry; and organismic topics which focus on plant groups such as algae, mosses or flowering plants.

<span class="mw-page-title-main">Propagation of grapevines</span>

The propagation of grapevines is an important consideration in commercial viticulture and winemaking. Grapevines, most of which belong to the Vitis vinifera family, produce one crop of fruit each growing season with a limited life span for individual vines. While some centenarian old vine examples of grape varieties exist, most grapevines are between the ages of 10 and 30 years. As vineyard owners seek to replant their vines, a number of techniques are available which may include planting a new cutting that has been selected by either clonal or mass (massal) selection. Vines can also be propagated by grafting a new plant vine upon existing rootstock or by layering one of the canes of an existing vine into the ground next to the vine and severing the connection when the new vine develops its own root system.

<span class="mw-page-title-main">Vivipary</span> Plant seeds developing before detachment

In plants, vivipary occurs when seeds or embryos begin to develop before they detach from the parent. Plants such as some Iridaceae and Agavoideae grow cormlets in the axils of their inflorescences. These fall and in favourable circumstances they have effectively a whole season's start over fallen seeds. Similarly, some Crassulaceae, such as Bryophyllum, develop and drop plantlets from notches in their leaves, ready to grow. Such production of embryos from somatic tissues is asexual vegetative reproduction that amounts to cloning.

Nurse grafting is a method of plant propagation that is used for hard-to-root plant material. If a desirable selection cannot be grown from seed, it must be propagated asexually (cloned) in order to be genetically identical to the parent. Nurse grafting allows a scion to develop its own roots instead of being grafted to a rootstock.

References

  1. "Vegetative plant propagation". Science Learning Hub. Retrieved 2021-06-15.
  2. Wang, Wenle; Xu, Jinfan; Fang, Huiyong; Li, Zhijun; Li, Minhui (2020-09-01). "Advances and challenges in medicinal plant breeding". Plant Science. 298: 110573. doi:10.1016/j.plantsci.2020.110573. ISSN   0168-9452.
  3. Bradshaw, John E. (2017). "Plant breeding: past, present and future". Euphytica. 213 (3). doi:10.1007/s10681-016-1815-y. ISSN   0014-2336.
  4. Hybrids of plant species being sterile, hybrids of same species are not
  5. GMO plant made to produce infertile seeds
  6. "Asexual Propagation". horti culture. Retrieved 9 April 2022.
  7. "13 heated propagators for nurturing your plants in 2023". BBC Gardeners World Magazine. Retrieved 18 October 2023.
  8. "Heated propagators: tried and tested". The English Garden. 17 January 2018. Retrieved 18 October 2023.
  9. Sheehan, Lindsay (6 January 2021). "5 Best Seedling Heat Mats For Faster Germination". Rural Sprout. Retrieved 17 October 2023.
  10. Dyer, Mary H. (5 October 2022). "What Does A Heat Mat Do – Using A Heat Mat For Seedlings". Gardening Know How. Retrieved 17 October 2023.

Bibliography