Vegetative reproduction

Vegetative reproduction is an increase in the number of organisms of a given species by separation from the vegetative body( the vegetative body is the most part of any organism: all but the sex cells or organs) of viable parts with the further regeneration of the parts to the whole daughter organism. Even some lower animals can reproduce in a similar way, for example, amoeba. In the case of flowers, vegetative reproduction is carried out with the help of stem and leaf cuttings, layers, parts of bushes, tubers and rhizomes. In industrial-laboratory cultivation of some plant species, the tissue method is also used, when instead of the whole organ or shoot a piece of tissue is taken, but at home it is impossible to propagate plants with its help.

Something scary seems to many people the words "cloning", "clone", and after all, from a purely biological point of view, a clone is any occurrence of a new plant vegetatively. Well, artificial vegetative reproduction is inherently cloning: the genetic material of the mother and daughter remains the same! The only exception is often attributed in the plant breeding literature to vegetative reproduction by special vaccination.

Most often we meet with cuttings. Cuttings are the rooting of parts of the stem( stem cuttings,) or leaf( leaf cuttings).However, only very few species can be cut directly into the soil, most of them require more care. For them, special land mixtures are often made, but it is convenient to use well-calcined sand or substratum fillers( like vermiculite) for rooting, which makes it possible to follow the condition of the lower sections: they must neither decay nor dry up.

The best period for cuttings of many ornamental plants is from mid-June to early July, when young shoots are lignified, others are preferable to cut in February-March, but there are species for which autumn will be the most favorable period, and some shrub and tree species are bettertake root in January - February.

Preparation of green cuttings is best done from the end of spring to mid-summer, harvesting of lignified cuttings - in the period of rest of plants. You can store the cuttings in the refrigerator or on the balcony at 2-6 ° C in plastic bags, and some even in glass jars covered with a dense cloth. Instead of fabric and conventional packages, you can use the recently appeared in the sale of special membranes. Nevertheless, the probability of successful rooting of the newly cut cuttings is much higher: it is very difficult to protect the long-term stalk from withering completely.

The average length of the stem cut should be 5 -15 cm( they should fit at least 1-2 internodes), and the length of some lignified cuttings and up to 20-25 cm, it should have several kidneys( at least 2-3).Leaf cuttings of herbaceous ornamental plants can consist of only a part of the leaf, and in shrub or tree species it is desirable to take cuttings with a "heel" - part of the shoot.

Separate from the mother plant cuttings with a sharp knife or razor, but sometimes tear off. The latter method is not very desirable, since it can cause excessive damage to the plant( it is relatively safe to separate lateral shoots of some plants).They use it often because of widespread superstition, as if the stolen plant, which is not bought, will best accrue in the house. Alas, only a few species can be treated this way painlessly.

If the plant has ducks and the cut stem is covered with droplets of their secret( i.e., the juice contained therein), it must be rinsed in warm water. There are other ways: remove the juice with a damp sponge, leave the stalk in a cold place for several hours or hold the cut for a few seconds over an open flame of a match, a cigarette lighter or a candle.

In a pot or drawer, the cuttings should be planted shallowly( up to 5 cm) at a distance of about 4 cm from each other. Then they are sprayed with water and for most species covered with a film: for cuttings, an increased atmospheric humidity is desirable. As already mentioned above, rooting of cuttings is difficult for some species without treatment with phytohormones of a number of auxins.

The basis for successful cuttings is the observance of optimal temperature, lighting and humidity regimes.

Moisture of the substrate( water should be warmer than room temperature) should be about 70%, air humidity for the cuttings should be about 90%, but as usual, do not get too carried away by watering: cuttings from excess moisture can corrupt. If you grow them under a film or frames, be sure to ventilate from time to time.

For cold-resistant species it is sufficient to maintain a constant temperature of about 18 - 20 ° C, that is, close to room temperature. For heat-loving crops, the soil should be warmed up better: some do not normally take root if the temperature does not exceed the usual temperature by 3-4 ° C.In addition, with the exception of cuttings of especially photophilous species, it is desirable( and some also necessary) to shade.

If everything is done correctly, after a couple of weeks( exact terms depend on the plant species), roots will appear. After rooting cuttings are planted in small pots.

Reproduction by layers in room conditions is relatively rare, more often it is dealt with by growing open ground plants: this method is applicable mainly to shrub and tree forms. However, many ampel plants( like ivy) can also be successfully multiplied by layers, that is, side shoots, which are bent down and buried with earth, and after the formation of the roots are cut off. In order to keep the springs under the soil layer, it can be pinned with a stud( preferably wooden).

In shoots turn shoots with well-developed leaves about 30 cm long. If the stem is long, for example in ivy, several layers can be made from it.

Citrus fruits and some other plants can be propagated similar, but still in a slightly different way. On the branch, cut a narrow cortex ring or cut out the windows in it( less often simply pull it with wire, making only small incisions), and put a patch of moistened moss or a bag without a bottom, or a container with a small amount of soil, so that they are wellThey covered the window or the place of the incision. Somewhere a month or more on the treated portion of the stem, the subordinate roots begin to form;when they are strong, this part of the plant can be cut and planted in a pot( in the case of a moss dressing, it is placed in the ground with the delenks).This method is called airborne multiplication.

Another method of vegetative propagation is used for highly expanding bushy plants( mainly ornamental plants) - this is the division of the bush. It is carried out in the following way: the mother plant is carefully taken out of the pot, released almost completely from the earth coma( it must be wet, so that the soil is more easily separated from the roots) and cut with a sharp knife into parts. Plants with a well-developed root system can also be separated by hands.

After this place, cut or scrap is sprinkled with charcoal, so that the wounds "dry up" more quickly, and the plants are planted in separate containers.

You need to water your daughter plants more often than usual. If the species does not have contraindications to spraying, it must be carried out.

Very similar to the tubers. They are planted in sandy loose ground and cut into pieces with a knife after the formation of sprouts so that on each part there is a sprout or kidney, then dried( the sections are best sprinkled with coal) and planted in pots.

Bulb propagation in most cases is a natural form of vegetative reproduction: babies( small daughter bulbs) form on the mother bulb independently, during the transplantation of bulbous species they are simply separated and placed in another container, first in the sand, then into the appropriate soil mixture. Sometimes the formation of children is provoked artificially by cutting the bulb's bottom or by its radial incisions: then very many of them can form.

The first five days of watering the separated tubers is not necessary, so that the damaged surface does not rot, and later they should be moistened with plenty of water.

Many species can be propagated by grafting - engrafting a part of one plant to another. Although in a strictly scientific sense this is not a complete breeding, for many species it gives excellent results: it helps to increase the resistance of plants and activate their growth. As a rule, vaccination is also done to give the plant a stronger foreign root system.

The best results are achieved when the graft and rootstock belong to different species of the same family.(Just in case, it is worth remembering the terms: a plant, part of which is grafted, is called a graft, and the one to which it is grafted is a stock.)

There are three main methods of grafting and several of their modifications: ocularization( engraftment of the kidney under the bark), inoculation of the cuttings and ablation - fusion of branches not separated from the stem.

When budding, take the kidney with a so-called scute - a small part of the stem. On the stock, make a T-cut( preferably with a special eyepiece knife), bend the bark to the side and plant under it the edge of the flap, and then press and wrap it with a narrow band. If part of the shield protrudes above the upper boundary of the cut, it is better to cut it. The bud can not be touched when taping is applied. For strapping, polyethylene, polyvinylchloride, linden bacon, rubber bands, twine and the like can be used, which tightly surrounds the site of inoculation.

Whether the kidney has got accustomed, it is possible to define in two weeks: if it has darkened, and the leaf petiole does not fall away when touched, the vaccination failed. The kidney should be green.

For budding, the best time is August, because the soil is sufficiently developed by that time, and the bark is easily separated from the wood.

Varieties of grafting cuttings are distinguished by the way of joining the graft to the rootstock. This can be done with an oblique cut, wedge, cuttings under the bark or with a groove.

Upper shoots for scions should have 2-3 buds. From the mother plant, they can be cut off in advance.

A graft is made with an oblique cut in the event that the graft and rootstock have approximately the same diameter. Sections are made at the same angle, and then they are joined so that no cracks remain, and they are tied up.

With a larger difference in the thickness of the stem, grafting with a wedge is used. In cut at the correct height, priovoe cut out a wedge-shaped depression, repeating the shape of the cut of the scion, and combine the parts.

If the difference in diameters of the graft and rootstock is quite large, it is better to make vertical incisions along the sides of the horizontally cut rootstock, bend the bark and insert a cut-off graft( or scion) into them and then tie it with tape.

When grafting, the horizontally truncated rootstock is cut vertically in the middle and split, and a slantwise cut graft is inserted into the cleavage. This option is often used for cacti. Cacti plant the tip.

The best period for grafting the cuttings shoot is April-May.

If the graft and the rootstock do not get well with each other, it is possible to inoculate the inoculation( ablation).At the same time, near the placed plants, the sections of the bark with wood are cut and the sections are wound together. When they grow together, the graft is cut from below, and the stock is topped.