Vegetative reproduction. What does the term mean? The value of vegetative reproduction

Reproduction is one of the characteristic features of all living organisms along with breathing, nutrition, movement and others. Its importance can not be overestimated, because it ensures the continuity of generations, and hence the very existence of life on planet Earth.

In nature, this process is carried out in different ways. One of them is asexual vegetative reproduction. It occurs mainly in plants. The significance of vegetative propagation and its variety will be examined in our publication.

What is asexual reproduction

The school biology course defines vegetative propagation of plants (Grade 6, section "Botany") as one of the asexual species. This means that in the course of its implementation, no sex cells participate. And, accordingly, recombination of genetic information is impossible.

This is the oldest method of reproduction, characteristic of plants, fungi, bacteria and some animals. Its essence lies in the formation of subsidiary individuals from the mother.

In addition to the vegetative, there are other ways of asexual reproduction. The most primitive of these is cell division in two. So single-celled animals and plants multiply, as well as bacteria.

Another type of this method is multiple division. It consists in the fact that from the same mother cell several children are formed simultaneously. This happens, for example, in malarial plasmodium, which parasitizes in blood cells.

A special form of asexual reproduction is the formation of spores. Horsetails, ferns, mosses and mosses reproduce this way.

Asexual vegetative reproduction

Often with asexual reproduction, a new organism develops from a whole group of parental cells. This kind of asexual reproduction is called vegetative.

Next, we describe the species and examples of organisms that are characterized by vegetative reproduction. The table listing them will help to get a general idea of the prevalence of this type of reproduction.

Reproduction by parts of vegetative organs

The vegetative organs of plants are the shoot consisting of a stem and leaf, and the root is an underground organ. By splitting off from them a multicellular part or petiole, a person can carry out vegetative reproduction.

What is cuttings for example? This is the method of said artificial vegetative propagation. So, to increase the number of bushes of currants or gooseberries, you need to take part of their root system with the kidneys, from which the escape will eventually recover.

But for the reproduction of grapes, stem stalks are suitable. After some time, the root system of the plant will be restored. A prerequisite is the presence of kidneys on any kind of petiole.

But for the reproduction of many indoor plants, leaves are often used. For sure, many bred in this way the violet of violets.

Reproduction by modified shoots

Many plants form a modification of the vegetative organs, which allow them to perform additional functions. One of these functions is vegetative reproduction. What is a special modification of shoots, we understand, if we consider separately rhizomes, bulbs and tubers.

Rhizome

This part of the plant is located underground and resembles a root, but, despite the name, is a modification of the escape. It consists of elongated internodes, from which the subordinate roots and leaves depart.

Examples of plants that reproduce with the help of rhizomes are lily of the valley, iris, mint. Sometimes this organ can also be found in weeds. Everyone knows how difficult it is to get rid of wheat grass. Squeezing it out of the ground, a person, as a rule, leaves parts of the overgrown rhizome rootgrass under the ground. And after a certain time they sprout again. Therefore, to get rid of this weed, it must be carefully dig.

Bulb

Leeks, garlic, narcissus also reproduce with the help of podemismal modifications of shoots, which are called bulbs. Their flat stem is called the Don. On it there are juicy fleshy leaves, storing nutrients, and kidneys. They give rise to new organisms. The bulb allows the plant to survive under the ground a difficult period for reproduction - drought or cold.

Tuber and mustache

To multiply potatoes, you do not need to sow seeds, despite the fact that it forms flowers and fruits. This plant reproduces by subterranean modifications of shoots - tubers. To multiply potatoes, it is not even necessary for the tuber to be whole. Enough of its fragment containing kidneys, which will germinate underground, restoring the entire plant as a whole.

And strawberries and strawberries, after flowering and fruiting, form terrestrial whips (whiskers), on which new shoots appear. By the way, they can not be confused with the antennae of grapes, for example. In this plant they perform a different function - the ability to gain a foothold on the support, for a more comfortable position in relation to the sun.

Fragmentation

Not only can plants reproduce by separating their multicellular parts. This phenomenon is observed in animals. Fragmentation as vegetative reproduction - what is it? This process is based on the ability of organisms to regenerate - the restoration of lost or damaged parts of the body. For example, from the part of the body of the earthworm, a whole individual can recover, including the integument and internal organs of the animal.

Pocification

Pocification is another way of reproduction, but vegetative kidneys to it have nothing to do with. Its essence is as follows: on the body of the mother's body protrusion is formed, it grows, acquires the features of an adult organism and splits off, starting an independent existence.

This process of budding occurs in freshwater hydra. But other representatives of coelenterates - coral polyps - formed protrusion is not split off, but remains on the mother's body. As a result, bizarre forms of reefs are formed.

Increasing the amount of dough, which is prepared with yeast, by the way, is also the result of their vegetative reproduction, by budding.

The value of vegetative reproduction

As you can see, vegetative reproduction in nature is widespread enough. This method leads to a rapid increase in the number of individuals of a particular species. In plants, for this, even there are a number of adaptations, in the form of modifications of the root and shoot.

Using artificial vegetative reproduction (which such a concept supposes already was said earlier), a person multiplies plants that he uses in his economic activities. It does not require an individual of the opposite sex. And for the germination of young plants or the development of new individuals, the habitual conditions in which the maternal organism lives are quite common.

However, all varieties of asexual reproduction, including vegetative reproduction, have one feature. Its result is the emergence of genetically identical organisms, which are an exact replica of the mother. To preserve the biological species and inherited features, this method of reproduction is ideal. But with the variability everything is much more complicated.

Asexual reproduction, on the whole, deprives organisms of the possibility of the appearance of new signs, and therefore of one of the ways of adaptation to changing environmental conditions. Therefore, most species in living nature are capable of sexual processes.

Despite this significant drawback, with the cultivation of cultivated plants, the most valuable and widely used is still vegetative reproduction. This method suits a person due to a wide variety of possibilities, small in duration, and the number of organisms that reproduce in the manner described.