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. [1]
Propagating plants from cuttings is an ancient form of cloning. [2] [3] There are several advantages of cuttings, mainly that the produced offspring are practically clones of their parent plants. If a plant has favorable traits, it can continue to pass down its advantageous genetic information to its offspring. This is especially economically advantageous as it allows commercial growers to clone a certain plant to ensure consistency throughout their crops. [4]
Cuttings are used as a method of asexual reproduction in succulent horticulture, commonly referred to as vegetative reproduction. A cutting can also be referred to as a propagule. Succulents have evolved with the ability to use adventitious root formation in reproduction to increase fitness in stressful environments. Succulents grow in shallow soils, rocky soils, and desert soils. [5] Seedlings from sexual reproduction have a low survival rate; however, plantlets from the excised stem cuttings and leaf cuttings, broken off in the natural environment, are more successful. [5]
Cuttings have both water and carbon stored and available, which are resources needed for plant establishment. The detached part of the plant remains physiologically active, allowing mitotic activity and new root structures to form for water and nutrient uptake. [5] Asexual reproduction of plants is also evolutionarily advantageous as it allows plantlets to be better suited to their environment through retention of epigenetic memory, heritable patterns of phenotypic differences that are not due to changes in DNA but rather histone modification and DNA methylation. [6] Epigenetic memory is heritable through mitosis, and thus advantageous stress response priming is retained in plantlets from excised stem. [6]
Adventitious root formation refers to roots that form from any structure of a plant that is not a root; these roots can form as part of normal development or due to a stress response. [7] Adventitious root formation from the excised stem cutting is a wound response.
At a molecular level when a cutting is first excised at the stem there is an immediate increase in jasmonic acid, known to be necessary for adventitious root formation. [8] When the cutting is excised from the original root system the root inhibiting hormones, cytokinin and strigolactone, which are made in the root and transported to the stem, decrease in concentration. [7] Polyphenol degradation decreases, increasing auxin concentration. The increased auxin concentration increases nitric oxide concentration which initiates root formation through a MAPK signal cascade and a cGMP-dependent pathway that both regulate mitotic division and are both necessary for the initiation of adventitious root formation. [9] The root primordia form from cambial cells in the stem. [7] In propagation of detached succulent leaves and leaf cuttings, the root primordia typically emerges from the basal callous tissue after the leaf primordia emerges. [5]
It was known as early as 1935 that when indolyl-3-acetic acid (IAA), also known as auxin, is applied to the stem of root cuttings, there is an increase in the average number of adventitious roots compared to cuttings that are not treated. Researchers also applied this compound to stems without leaves that normally would not have any root formation and found that auxin induced root formation, thus determining auxin is necessary for root formation. [10] Identification of this hormone has been important to industries that rely on vegetative propagation, [7] as it is sometimes applied to fresh cuttings to stimulate root growth.
Some plants form roots much more easily than others. Stem cuttings from woody plants are treated differently, depending on the maturity of the wood:
Most plant cuttings are stem pieces, and have no root system of their own, and are therefore likely to die from dehydration if the proper conditions are not met. They require a moist medium, which, however, cannot be too wet lest the cutting rot. A number of media are used in this process, including but not limited to soil, perlite, vermiculite, coir, rock wool, expanded clay pellets, and even water given the right conditions. Most succulent cuttings can be left in open air until the cut surface dries, which may improve root formation when the cutting is later planted.
In temperate countries, stem cuttings may be taken of soft (green or semi-ripe) wood and hard wood, which have specific differences in practice. Certain conditions lead to more favorable outcomes for cuttings; timing, size, location on the plant, and amount of foliage are all important. Stem cuttings of young wood should be taken in spring from the upper branches, while cuttings of hardened wood should be taken in winter from the lower branches. Common bounds on the length of stem cuttings are between 5–15 centimetres (2.0–5.9 in) for soft wood and between 20–25 centimetres (7.9–9.8 in) for hard wood. Soft wood cuttings do best when about two thirds of the foliage are removed, [13] while hard wood stem cuttings need complete foliage removal. The cut needs to be done either immediately below a node, [14] or up to 1/2 inch below a node. [15]
Besides placing the cuttings directly into soil, it is also possible to root cuttings in water. The water needs to be replaced often, to prevent bacteria buildup and the possibility of root rot. It also requires enough oxygen in the water for the same reason. A moist atmosphere (use of plastic sheeting) is hence not needed with this technique. [16] [17]
The environment for softwood and semi-hardwood cuttings is generally kept humid—often attained by placing the cuttings under a plastic sheet or in another confined space where the air can be kept moist—and in partial shade to prevent the cutting from drying out. Cuttings in the medium are typically watered with a fine mist to avoid disturbing the plants. Following the initial watering, the aim is to keep the soil moist but not wet or waterlogged; the medium is allowed to almost dry out before misting again. [13]
A rooting hormone may be administered to "encourage" growth and can increase the success rate of plant growth. [18] Though not essential, several compounds may be used to promote the formation of roots through the signaling activity of plant hormone auxins. Among the commonly used chemicals is indole-3-butyric acid (IBA) used as a powder, liquid solution, or gel. This compound is applied either to the cut tip of the cutting or as a foliar spray. Rooting hormone can be manufactured naturally, such as soaking the yellow-tipped shoots of a weeping willow tree in water, or by preparing a tea from the bark of a willow tree. Shoots or bark do better when soaked for 24 hours prior to using. [19] The extract obtained from the crushing of leaves and bulbs of coco-grass ( Cyperus rotundus ) is used as an excellent rooting of cuttings and seedlings of various plant species. [20] [21] Honey, though it does not contain any plant hormones, can also aid in rooting success through its natural antiseptic and antifungal properties. [22] [23] Cinnamon [ citation needed ] or an Aspirin tablet in water [24] can also aid the rooting process. [25]
Many vegetative parts of a plant can be used. The most common methods are:
Although some species, such as willow, blackberry and pelargoniums can be grown simply by placing a cutting into moist ground, the majority of species require more attention. Most species require humid, warm, partially shaded conditions to strike, thus requiring the approach above to be followed. Particularly difficult species may need cool air above and warm soil. In addition, with many more difficult cuttings, one should use the type of cutting that has the most chance of success with that particular plant species. [28]
There are ways of improving the growth of stem cutting propagations. Intensifying light allows cuttings to root and sprout faster, though the heat thus generated could cause the propagation material distress. [29] Azalea cuttings can be mildly heated in water to disinfect it from the fungus pathogen Rhizoctonia, and this could potentially be used for other plants. [30]
Depending on the type of cutting (i.e. tree, shrub, succulent, cacti) different potting soil mixes can be used. Many commercial companies sell medium specifically for growing cuttings.
Although several options can be used here, usually plastic is used to cover the softwood and semi-hardwood cuttings. The soil below the trays (to increase air moisture) and the soil in the trays themselves is kept moist but not waterlogged (=completely saturated). The trays the cuttings sit in are best placed on stones to prevent capillary action (as this can keep the soil inside the trays too wet). Soil in the trays should be kept at 85 to 95% saturation. [31] Automated (overhead) misting systems, boom systems or fog systems [32] can be used in greenhouses.
A typical misting frequency during sticking and callusing includes misting for 5–8 seconds every 5–10 minutes over a 24-hour period. After 3 to 4 days, misting is reduced to 3–5 seconds every 10–20 minutes during the day and less frequently at night. When roots become visible (stage 3) misting can be reduced, and by stage 4 (toning), little to no misting should be done (by day 10 to 14 for most species [31] ). [32] When using plastic tents, far less misting is needed (once or twice a day). [33] The greenhouse or cold frame should be ventilated once in a while [34] to prevent formation of molds (manually).
Air temperature for softwood and semi-hardwood cuttings is optimal at around 70 °F [35] [36] [37] [38] (21.1 °C) but temperatures as low as 55 °F (12.7 °C) are acceptable. Heating the air above 75 °F (23.8 °C) stimulates the growth of pathogens. [35] Ventilating (manually or through automatic window openers) the greenhouse or cold frame can lower the air temperature. Automated thermostat systems can also be used in greenhouses to keep the heat at a specific temperature. Bottom heating (soil) tends to be ideal for root initiation since growing media temperature is best maintained at 20-22 °C. [31]
Whereas cuttings need to be kept warm and some amount of light needs to be provided, it needs to be kept out of direct sunlight. [39] Some ways to accomplish this include using white wash, semi-white plastic, retractible shade curtains (which can be deployed if the sun temporarily pierces through), ... Optimum light levels are around 120 to 200 μmol/m2s at the first stage (sticking [32] ). Once callus has been formed (stage 2: callusing [32] ) and roots start to form and take up water (stage 3: root development phase), light intensity levels can be gradually increased (to 200 to 800 μmol/m2s). [40] [41] Most propagators find that 5 to 10 moles per day (i.e. observed using a Daily Light Integral sensor) will result in a consistent rooting and growth [31]
Plants which can be propagated from stem, leaf and/or tip cuttings include: [42] [ failed verification – see discussion ]
To note, some plants listed above, such as Coleus, Maranta, Nerium and Golden Pothos, among others, may require water for them to root before they can be transplanted to soil.
The poet Theodore Roethke wrote about plant cuttings and root growth behavior in his poems "Cuttings" and "Cuttings (Later)" found in his book The Lost Son: And Other Poems. [43]
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the surface of the soil, but roots can also be aerial or aerating, that is, growing up above the ground or especially above water.
Tubers are a type of enlarged structure that plants use as storage organs for nutrients, derived from stems or roots. Tubers help plants perennate, provide energy and nutrients, and are a means of asexual reproduction.
Vegetative reproduction is a 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.
Auxins are a class of plant hormones with some morphogen-like characteristics. Auxins play a cardinal role in coordination of many growth and behavioral processes in plant life cycles and are essential for plant body development. The Dutch biologist Frits Warmolt Went first described auxins and their role in plant growth in the 1920s. Kenneth V. Thimann became the first to isolate one of these phytohormones and to determine its chemical structure as indole-3-acetic acid (IAA). Went and Thimann co-authored a book on plant hormones, Phytohormones, in 1937.
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 and natural processes.
Aerial roots are roots growing above the ground. They are often adventitious, i.e. formed from nonroot tissue. They are found in diverse plant species, including epiphytes such as orchids (Orchidaceae), tropical coastal swamp trees such as mangroves, banyan figs, the warm-temperate rainforest rata, and pohutukawa trees of New Zealand. Vines such as common ivy and poison ivy also have aerial roots.
Aeroponics is the process of cultivating plants in an air or mist environment, eliminating the need for soil or an aggregate medium. The term "aeroponic" originates from the ancient Greek: aer (air) and ponos. It falls under the category of hydroponics, as water is employed in aeroponics to deliver nutrients to the plants.
In biology, stolons, also known as runners, are horizontal connections between parts of an organism. They may be part of the organism, or of its skeleton. Typically, animal stolons are exoskeletons.
Micropropagation or tissue culture is the practice of rapidly multiplying plant stock material to produce many progeny plants, using modern plant tissue culture methods.
Layering is a vegetative propagation technique where the stem or branch of a plant is manipulated to promote root development while still attached to the parent plant. Once roots are established, the new plant can be detached from the parent and planted. Layering is utilized by horticulturists to propagate desirable plants.
A primordium in embryology, is an organ or tissue in its earliest recognizable stage of development. Cells of the primordium are called primordial cells. A primordium is the simplest set of cells capable of triggering growth of the would-be organ and the initial foundation from which an organ is able to grow. In flowering plants, a floral primordium gives rise to a flower.
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.
This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnifying lens. This page provides help in understanding the numerous other pages describing plants by their various taxa. The accompanying page—Plant morphology—provides an overview of the science of the external form of plants. There is also an alphabetical list: Glossary of botanical terms. In contrast, this page deals with botanical terms in a systematic manner, with some illustrations, and organized by plant anatomy and function in plant physiology.
Important structures in plant development are buds, shoots, roots, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born, it has all its body parts and from that point will only grow larger and more mature. However, both plants and animals pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification.
Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues, or organs under sterile conditions on a nutrient culture medium of known composition. It is widely used to produce clones of a plant in a method known as micropropagation. Different techniques in plant tissue culture may offer certain advantages over traditional methods of propagation, including:
Dracaena pinguicula, synonym Sansevieria pinguicula, also known as the walking sansevieria, is a xerophytic CAM succulent native to the Bura area of Kenya, near Garissa. The species was described by Peter René Oscar Bally in 1943.
Crassula ovata, commonly known as jade plant, lucky plant, money plant or money tree, is a succulent plant with small pink or white flowers that is native to the KwaZulu-Natal and Eastern Cape provinces of South Africa, and Mozambique; it is common as a houseplant worldwide. Much of its popularity stems from the low levels of care needed; the jade plant requires little water and can survive in most indoor conditions. It is sometimes referred to as the money tree; however, Pachira aquatica also has this nickname.
Kalanchoe longiflora, also known as tugela cliff-kalanchoe or long-flower kalanchoe, is a species of the succulent genus Kalanchoe, in the family Crassulaceae. An obscure shrub native to South Africa, it is known for its multi-coloured foliage and yellow flowers, which bloom in autumn to winter.
A canopy root, also known as an arboreal root, is a type of root that grows out of a tree branch underneath an epiphytic mat. These adventitious roots form in response to moist, dark, nutrient-rich conditions that are found in “canopy soils”. Canopy roots have been found in species of maple, poplar, alder, myrtle, beech, and spruce, among many others. They are structurally similar to roots found on the forest floor and likely serve a similar purpose for water and nutrient uptake, though their specific functions are still being studied.
{{cite journal}}
: CS1 maint: DOI inactive as of September 2024 (link)