During vegetative reproduction, the number of individuals increases as a result of one or another division of the body of one parent organism. Thus, vegetative reproduction is one of the types of asexual reproduction, when the daughter organism is an exact genetic copy of the maternal one.
In the case of angiosperms, vegetative propagation is carried out by shoots, roots and leaves, i.e. vegetative organs. Most often, reproduction occurs by shoots.
In angiosperms, herbaceous plants vegetative propagation is often carried out by underground shoots (rhizomes, bulbs, tubers). These organs serve not only to accumulate a supply of nutrients for the development of green parts of plants in the next growing season. They can also be considered as organs of vegetative reproduction.
The buds of underground shoots give rise to aboveground green shoots. Such new shoots may become separated from the parent plant, i.e., give rise to a new plant.
So plants that have underground rhizomes are very tenacious. If you pull out the parent plant, new green shoots will develop in the soil from the buds of the remnants of the rhizome.
Baby bulbs often form in bulbs from buds. Having separated from each other, each of them gives rise to a new plant.
The tubers also have buds (eyes), which under favorable conditions germinate and develop into a separate plant. If a potato tuber is cut into several parts, each of which contains eyes, you can get several individual plants.
Also many angiosperms plants are able to reproduce vegetatively by above-ground shoots. For example, strawberries form tendrils, which are creeping green stems. At their nodes shoots with leaves and adventitious roots develop. Each such daughter shoot can be separated from the parent plant.
In woody plants, vegetative propagation can occur through the rooting of aboveground shoots, usually branches. Branches pressed to the soil can take root and develop into a separate bush or tree.
A number of angiospermscan propagate by root cuttings or root suckers. A root cutting is a separated part of a root with adventitious buds. From these buds shoots develop, which subsequently take root. Propagation by root cuttings is typical for dandelion, raspberry, rose hip, etc.
However, in the same raspberries, propagation by root suckers is more common. Offshoots from cuttings differ in that they are not separated from the parent plant. The root shoot spreads into the surface layers of the soil. Adventitious buds grow on it, which give rise to above-ground shoots, each of which can be separated from the parent plant. It is the root suckers that produce dense young growth near trees or stumps.
Some angiosperms can propagate vegetatively from leaf cuttings. Once in favorable conditions, the separated leaf can take on adventitious roots; adventitious buds also develop on it, from which shoots grow.
Vegetative propagation of plants is widespread not only in nature. Man actively uses this ability of plants in agriculture. Vegetative propagation allows you to get a harvest faster and preserve valuable characteristics of the variety. The following types of vegetative propagation are used in agriculture: stem cuttings, layering, rhizomes, bulbs, tubers, grafting, etc.
Vegetative propagation the formation of a new organism from a part of the maternal one. The methods of V. r. observed in nature are varied. The simplest of them is the restoration of the organism from one vegetative cell as a result of its sequential division and differentiation of the resulting cells. V. r. characteristic of microorganisms, low-organized animals, and almost all plants. In animals V. r. carried out by budding (for example, in sponges, coelenterates, bryozoans) or division (for example, in protozoa); in unicellular plants (algae, fungi, etc.) - more often by division, less often by budding; in lower multicellular plants, by disintegration of the body into separate sections capable of regeneration(recovery). Higher plants can reproduce by rhizomes, suckers, bulbs, tubers, and other vegetative organs (See Vegetative Organs). In many cultivated plants, V. r. - the only possible way to preserve valuable varietal characteristics and properties. In higher plants, reproduction occurs by layering (fir, rhododendrons, wild forms of grapes, etc.), that is, by parts of organs whose connection with the mother plant is maintained until they begin to feed on their own; lashes or mustaches (strawberries - rice. 1
, blackberries, sweet potatoes, creeping buttercups, budra, etc.); root suckers (many deciduous and coniferous trees and grasses - rowan, rose, alder, tausagyz, field sow thistle, etc.). Many vegetable and ornamental plants (onions, tulips, lilies, potatoes, sweet potatoes and many others) reproduce by bulbs and tubers; as a rule, perennial plants (lily of the valley, mint, asparagus, bamboo and many weeds) propagate by rhizomes. In plant growing, propagation by cuttings (stem, root and leaf) is widespread. Natural reproduction by leaves is characteristic of bryophyllum, in which the shoots formed on the leaf blades fall off and take root in the soil. In fruit growing, own-root methods of V. r. are used. (propagation by layering and cuttings) and grafting (see Grafting in plant growing) .
Layering is a part of a ground stem with buds that is not separated from the mother plant during the rooting period. Stems to be rooted are hilled. Rooted stems are separated from the mother plant, cut into pieces (having roots) and immediately planted on a plantation or grown in a nursery (1-2 years). Many types of agricultural products and ornamental plants (blackberry, ivy, sumac, mackerel, rhododendron, etc.) are propagated by natural layering ( rice. 2
). In fruit growing, propagation by vertical and horizontal layering is most often used; This is how many varieties of gooseberries, some apple tree rootstocks are propagated, and in ornamental gardening - lilac, viburnum, honeysuckle, etc. Many varieties of blackberries and blackberry-like raspberries are propagated by apical layering. When cuttings, parts of the plant (cuttings) are used that, under certain conditions, are capable of restoring roots (on stems), or buds (on roots), or buds and roots (on leaves). There are stem, leaf and root cuttings. Stem cuttings can be without leaves (winter), with leaves (summer, or green), herbaceous and woody. Leafless cuttings are usually harvested in the fall, often from annual shoots, which are cut into pieces 20-30 in length. cm, planted in autumn or spring, keeping them buried in the basement, in the snow. Winter cuttings are used to propagate grapes, some varieties of gooseberries, some types of apple and plum rootstocks, quince, figs, pomegranates, spirea, jasmine, poplar, willow, etc. For green cuttings, leafy shoots are used, cutting them into pieces 5-10 in length cm, sometimes a part of the bark with wood and one bud (leaf cuttings) is cut from the stem. Green cuttings are used to propagate gooseberries, cherries, plums, quince, sea buckthorn, olives, many ornamental shrubs and herbaceous flowering plants - chrysanthemum, geranium, carnation, dahlia, phlox, etc. The process of root formation in green cuttings of many plants is stimulated with the help of growth substances (See. Growth substances). In cherries, plums, lilacs, etc., green cuttings take root more easily during the period when the cuttings are in a phase of intensive growth in length; in apple trees, gooseberries, etc. - at the end of this phase, and in black currants and some varieties of gooseberries - during the entire growth phase. Temperature (optimal 20-25°C), air and substrate humidity, and light conditions are of great importance when propagating from green cuttings. For green cuttings, artificial fog is used, created by automated systems above the rooting site of the cuttings. In an atmosphere of fog, the rooting rate of cuttings increases sharply, and labor costs are reduced by 2-3 times. A leaf stalk is a leaf or part of a leaf. The leaf is planted in the rooting medium (usually sand) with the petiole or laid with the underside, slightly cutting the convex veins of the leaf. Then lightly sprinkle with sand and water. Begonia, sedum, Uzambara (African) violet, etc. are propagated by leaf cuttings. Root cuttings are parts of the root; They are usually harvested in the fall, 10-15 in length cm, stored buried in sand and peat, planted in fertile soil in the spring. Root cuttings are used to propagate raspberries (red), blackberries, young apple tree seedlings, some varieties of cherries, plums, etc. Lit.: Krenke N.P., Plant regeneration, M. - L., 1950; Turetskaya R. X., physiology of root formation in cuttings and growth stimulants, M., 1961; Hartman X. T., Kester D. E., Reproduction of garden plants, trans. from English, M., 1963; Zhukovsky P. M., Botany, 4th ed., M., 1964. M. T. Tarasenko.
Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .
There are several main ways to propagate plants: they can be sown in the ground (open or closed) with seeds or seedlings can be obtained from them, bulbs, tubers or rhizomes can be divided. There are also less common options - propagation of vegetables by cuttings, layering and grafting. Vegetative methods of plant propagation are those that involve parts of crops.
They are resorted to for a number of reasons:
- there are crops that do not produce seeds, for example garlic, horseradish, multi-tiered onions;
- some vegetables (potatoes, spicy varieties of onions), sown with seeds, form small productive organs in the first year - such as sets;
- gardeners cultivate plants that, when grown from seeds, produce strong splitting (as when sowing seeds collected from hybrids), for example rhubarb;
- There are crops that have very small seeds that are difficult to germinate, and it takes 70-90 days to grow seedlings. These include artichoke, rosemary, tarragon, etc. Therefore, it is simply more convenient to grow them using the vegetative method of propagating cultivated plants.
Different methods of propagating vegetable crops
In practice, propagation of vegetable crops by dividing bulbs is common. For example, a multi-bud onion forms a fairly large number of bulbs - 3-12 pieces, into which it can be divided and then planted in beds. You can divide the bulbs not only by the number of children, but also into parts - by the number of embryos. Using this method of plant propagation, cut off the upper part of the bulb “up to the shoulders”; on the cross section you will see the rudiments, into which you will need to disassemble the bulb. When they dry out a little in the air, plant them in the same way as sets (bulbs grown from seeds and having a diameter of 1.5-2.2 cm) or selections (bulbs with a diameter of 3-4 cm).
There is a rule that, if followed, will allow you to grow a good harvest of shallots, multi-tiered onions and garlic: before sowing the bulbs, calibrate them by size and plant them at a depth that is 3 times their height. Then the plants will develop equally and at the same time produce a harvest.
What other methods of plant propagation do gardeners use? Perennial crops, such as asparagus, rhubarb, lovage, mint, thyme, etc., reproduce by dividing the rhizomes. It contains a sufficient supply of nutrients to support the vital activity of young plants until they develop their own root system. Divide the rhizomes into parts in the fall or spring and immediately plant them in a garden bed where they will grow for several years.
Artichoke and lemon balm provide root shoots. But their root system is quite weak, so in order for it to take root after the separation of the daughter plant from the mother plant, it must be grown in a nursery.
Vegetable plants such as potatoes, Jerusalem artichoke and stachys are propagated by dividing the tubers, based on the biological characteristics of these crops. A tuber is a modified thickened shoot, so potatoes are not a root crop, like carrots or beets (their fruit is a thickened root), but a tuber crop. At its top there are buds - eyes, which are unevenly distributed throughout the tuber. With 12 eyes 6-7 pcs. will fall on the top third, on the middle third - 1-2 pieces, on the bottom third - 2-3 pieces. When cutting the tuber, make sure that there are several eyes for each part.
How else does a person propagate cultivated plants that have tubers? Potatoes can also be propagated by eyes and sprouts (layers). In the first case, cut out the eyes in the form of cones, and the tubers themselves can be used for food. Leave the eyes in the air for several hours so that they wilt a little, pour them into a box in a small layer and store at a temperature of 3-4 ° C. During planting, place 2-3 eyes in each hole. By providing optimal care, you will get a good potato harvest.
Using this method of propagating vegetable plants, potatoes must undergo vernalization to produce sprouts. To do this, leave the tubers in the light for about 30 days at a temperature of 16-17 ° C. After the formation of sprouts 10-15 cm long on them, lay the potatoes in layers, alternating each of them with humus or peat. After 4-6 days, the root system will develop on the sprouts. Separate them from the tuber (try not to damage the eyes) and plant them in a plot (at a distance of 20 cm from each other, and there should be 50 cm between rows) or in a nursery for growing (this is how sweet potatoes are usually cultivated). Further care does not differ from the generally accepted one.
When practicing plant propagation in different ways, experienced gardeners use grafting. Reproduction by grafting is a method better known in fruit growing. It was first applied to vegetables by I.V. Michurin. Of course, grafting is not so common in vegetable growing, however, tomatoes can be grafted onto potatoes, sunflowers onto Jerusalem artichokes, cucumbers and melons onto pumpkins. This method is used to the greatest extent in breeding, but it is not found in the practice of amateur vegetable growing.
Method of propagating vegetable plants by cuttings
What other methods of plant propagation are there, and how to use them? Tomatoes can be propagated by cuttings, especially if the plants are very elongated or if there are not enough seeds. Cut off the top and shoots of the seedling and root. From such cuttings, completely conditioned bushes will grow. At the same time, the mother plant planted in the ground will also develop normally and bear fruit.
Using the method of propagating plants by cuttings is associated with one difficulty - maintaining viability until they develop a full-fledged root system. This can only be achieved if they are provided with heat, light and moisture, which is possible in a greenhouse. In the process of propagating various cultivated plants by cuttings, he will need boxes filled with perlite or vermiculite, that is, sterile, light and loose substrates that can create optimal conditions for a new root system. You can use compost, humus, and rotted sawdust pre-treated with fertilizers.
In addition to tomatoes, stem cuttings are used for potatoes, lovage, marjoram, and tarragon. It is important to choose the right cuttings, which should be neither too young (they do not give roots well) nor too old (they dry out, since a large amount of nutrients is used to maintain the developed vegetative organs - leaves). Therefore, choose healthy shoots, free from pests and diseases, that are just beginning to become woody. To stimulate the formation of roots, use heteroauxin, for which dissolve 2 tablets in a glass of hot water, pour in water at room temperature, bringing the amount to 10 liters, and keep the cuttings in the liquid for 6 hours.
The survival rate of cuttings will increase if you soak them in a 0.005% sodium humate solution. To obtain a liquid of this concentration, dilute 10 g of the drug in 150 ml of water and leave for 1 day, then drain the solution, and pour 20 ml of sediment into 10 liters of water.
Cuttings come not only from stems, but also from roots. This is how artichokes, rosemary and horseradish are grown. For example, prepare horseradish cuttings 15-20 cm long in the fall and store them in the basement in the sand until the next season. Before planting, wipe them with a cloth, removing all the buds in the middle. And in artichoke, root cuttings are grouped around the mother plant; they can simply be separated with a knife and planted in a permanent place.
Methods of vegetative propagation of plants
Vegetative propagation of plants is carried out using various methods: rhizomes, cuttings, tendrils or bulbs. The cuttings option is the most common when it comes to house plants.
What does the concept of vegetative propagation mean?
Vegetative propagation is one of the methods of propagation that involves growing a new plant using its mother part. The second name for this technique is asexual reproduction. It has a number of advantages, the main one of which is the complete preservation of all generic characteristics of the mother plant.
Source: Depositphotos
Vegetative propagation of plants is possible in several ways
The most popular methods of vegetative propagation:
- Seeds.
- Dividing the bush.
Scheme 1 Reproduction using air layering. 1 - Maternal branch; 2 - Formation of roots at the site of bark removal;
3 - The transplant process itself.
- Air layering (see diagram 1.) To carry out this type of propagation, make an incision on a branch 1.5 cm long. Lubricate the area where the bark was removed with phytohormone. The plastic film is well secured to the stem of the plant and sphagnum moss or other substrate is sprinkled. Tie the other end of the film and wait for the roots to form.
- Vaccination (see diagram 2)
- Offspring (see diagram 3).
Scheme 4. Reproduction by tendrils or ground stolons contributes to the rapid rooting of a young plant
- Whiskers or ground stolons (see diagram 4)
- Leaves.
Since the simplest method is dividing the bush, let's talk about this method in more detail.
Dividing a bush as a method of vegetative propagation
Scheme 5. Dividing a bush is a simple method of vegetative propagation. 1 - main plant; 2 - the process of dividing a plant bush.
Dividing a bush is the most primitive, simple and cheapest propagation method. Dividing is very easy:
- Carefully remove the plant from the pot and shake off the soil mixture.
- Divide the plant into 2 equal parts. Please note that each part must have young buds.
- Transplant both parts into different pots with previously prepared soil.
Nothing else is needed to successfully divide the bush. With the right approach to propagation, both plants will take root well in new pots, and all you have to do is regularly care for them.
Vegetative propagation by leaf cuttings
There is also nothing difficult about this propagation technique. It is suitable for mature healthy plants with developed fleshy leaves. Reproduction is done like this:
- Lightly press a healthy, dense leaf into wet sand.
- When the leaf sprouts roots, plant it in previously prepared soil.
- Until the leaf gets stronger, water it with a sprayer twice a day. Cover the cutting with a plastic cup, creating greenhouse conditions.
When the plant becomes noticeably stronger, remove the glass and begin caring for it as usual.
Propagation by cuttings
Most often in nature, plants reproduce by cuttings - when the wind breaks the shoots, the roots remaining in the soil become tied into new young stems. Propagation by cuttings is carried out as follows:
- Separate a twig with several buds from the mother shoot.
- Place the twig in clean water at room temperature.
- When adventitious roots form on the branch, transplant it into a plastic cup with a damp substrate.
- When the plant gets stronger, transplant it to a permanent place.
Vegetative or asexual propagation is practiced for both indoor plants and outdoor trees, flowers and shrubs. This is a universal technique that allows you to experiment with the characteristics of varieties, create hybrid varieties, or develop new plants previously unknown to science. This is also the safest propagation option - the risk of accidentally harming the plant is minimal.
Vegetative propagation plants- this is the development of new plants from vegetative organs or their parts. Vegetative propagation is based on the plant’s ability to regenerate, i.e., to restore a whole organism from a part. During vegetative propagation, new plants are formed from shoots, leaves, roots, tubers, bulbs, and root suckers. The new generation has all the qualities that the mother plant has.
Vegetative propagation of plants occurs naturally or with human help. People widely use vegetative propagation of indoor, ornamental, and vegetable plants. For this, first of all, those methods that exist in nature are used.
Wheatgrass, lily of the valley, and kupena reproduce by rhizomes. Rhizomes have adventitious roots, as well as apical and axillary buds. The plant, in the form of a rhizome, overwinters in the soil. In spring, young shoots develop from the buds. If the rhizomes are damaged, each piece can produce a new plant.
Some plants reproduce from broken branches (willow, poplar).
Reproduction by leaves occurs less frequently. It is found, for example, in meadow heart. In moist soil, an adventitious bud develops at the base of the broken leaf, from which a new plant grows.
Potatoes are propagated by tubers. When planting a club, part of the buds develops into green shoots. Later, from another part of the buds, rhizome-like underground shoots - stolons - are formed. The tops of the stolons thicken and turn into new tubers (Fig. 144).
Onions, garlic, and tulips reproduce by bulbs. When planting bulbs in the soil, adventitious roots grow from the bottom. Daughter bulbs are formed from axillary buds.
Many shrubs and perennial herbs are propagated by dividing the bush, for example peonies, irises, hydrangeas, etc.
Scientists have developed methods of vegetative propagation that are extremely rare in nature (cuttings) or do not exist at all (grafting).
Cutting-forging
When cuttings, part of the mother plant is separated and rooted. A cutting is a part of any vegetative organ - a shoot (stem, leaf), root. The cuttings usually already have buds, or they may appear under favorable conditions. A new plant grows from the cuttings, completely similar to the mother one.
Many indoor plants, tradescantia, pelargonium, and coleus, are propagated by green leafy shoot cuttings (Fig. 145). Gooseberries, currants, nil, willow and other plants are propagated by leafless cuttings (a section of a young stem with several buds).
Begonia, glock blue, Uzambara violet, sansevieria (pike tail) and many other indoor plants are propagated by leaf cuttings. To do this, a separate leaf is planted in damp sand, covered with a glass cap, or placed in water (Fig. 146).
Raspberries are propagated by root cuttings.
Layerings
Layerings are used for propagating gooseberries, currants, and linden. In this case, the lower branches of the bush are bent to the ground, pressed and sprinkled with soil. It is recommended to make cuts on the underside of the bent branch to stimulate the formation of adventitious roots. After rooting, the cutting branch is separated from the mother plant and transplanted to a permanent place (Fig. 147).
Plant grafting
When grown from seeds, apple trees, pears and other fruit plants do not retain the valuable qualities of the original plant. They become wild, so such plants are propagated by grafting. The plant that is grafted onto is called the rootstock, and the plant that is grafted onto is called the scion. A distinction is made between grafting with an eye and grafting with a cutting (Fig. 148).
Inoculation
Eye grafting is carried out as follows. In the spring, during sap flow, a T-shaped cut is made on the bark of the rootstock. Then the corners of the bark are folded back and a bud cut from the scion with a small section of bark and wood is inserted under it. The bark of the rootstock is pressed, and the wound is bandaged with a special adhesive tape. The part of the rootstock located above the scion is removed.
Grafting with cuttings
Grafting with cuttings is done in different ways: by butt (cambium on cambium), split, under the bark. With all methods, it is important to observe the basic condition: the cambium of the scion and the cambium of the rootstock must match. Only in this case will fusion occur. As with kidney grafting, the wound is bandaged. The sites of correctly performed grafting quickly grow together. Material from the site
Plant tissue culture
In recent decades, such a method of vegetative propagation as tissue culture has been developed. The essence of the method is that a whole plant is grown from a piece of educational (or other) tissue or even from one cell on a nutrient medium under careful observation of lighting and temperature conditions. At the same time, it is important to prevent the plant from being damaged by microorganisms. The value of the method is that, without waiting for seeds to form, you can get a large number of plants.
Vegetative propagation of plants is of great biological and economic importance. It promotes fairly rapid dispersal of plants.
During vegetative propagation, the new generation has all the qualities of the mother’s organism, which allows the preservation of plant varieties with valuable traits. Therefore, many fruit crops reproduce only vegetatively. When propagated by grafting, the new plant immediately has a powerful root system, which allows it to provide young plants with water and minerals. Such plants turn out to be more competitive compared to seedlings emerging from seeds. However, this method also has disadvantages: with repeated repetitions of vegetative propagation, “aging” of the original plant occurs. This reduces its resistance to environmental conditions and diseases.
