Taproot. Types of root systems Root system taproot rhizome

The root is a vegetative organ of a plant with positive geotropism (growing in the direction of gravity), having a cylindrical shape and radial symmetry. As long as there is an apical (apical) meristem at the root tip, the root is capable of growth. The key difference between a root and a shoot is that the apical meristem is protected by a root cap that covers it. Remember also that leaves can never be found on the root. The main functions of the root:

• Support function - fixes the plant in the soil (anchoring)
• Absorption of water and minerals dissolved in it from the soil solution
• Synthesis of organic substances - in the cells of the root, compounds important for the plant are formed (alkaloids, hormones, amino acids)
• Storage of nutrients - the root accumulates starch, oils
• Vegetative propagation - can be carried out by parts of the root

Sometimes adventitious buds are laid on the roots - this is the name of the buds that are laid outside the typical places for the development of the kidneys (outside the leaf axil and the top of the shoot). Shoots sprout from them, often called root shoots or root offspring.

• Symbiosis with bacteria, fungi

Nodule (nitrogen-fixing) bacteria are combined on the roots into special formations - nodules. These bacteria are able to convert atmospheric nitrogen (molecular substance) into nitrogen-containing complex substances that are absorbed by plants. With the mycelium of fungi, the root forms a symbiosis, which is called mycorrhiza (or fungus root).

Root system and origin of roots

The root system is made up of all the roots of a plant. It provides reliable anchoring of the plant in the soil. There are three main types of plants:

• Tap root system

Well expressed, developed main root, stands out from the rest of the roots. Lateral and adventitious roots are not distinguished, they occupy a subordinate position in relation to the main one. It is typical for dicotyledonous plants: clover, medicinal dandelion, burdock.

• fibrous root system

The main root is not developed or quickly dies off, adventitious roots growing from the shoot predominate. Roots are equivalent to each other. The fibrous system is characteristic of most monocotyledonous plants: onion, cereals, large plantain, caustic buttercup.

• Mixed root system

You can distinguish the main root, it stands out in size. However, multiple adventitious and lateral roots are well developed. A mixed root system is typical for strawberries, strawberries.

Root zones are a reflection of its growth and development. I always tell my students that imagination is the most important thing. Imagine a root growing deep into the soil. He faces many problems and tasks that root zones help to solve. As it grows deeper, the root zones replace each other in the direction of growth. So, what are the zones of the roots?

• Breeding zone (division)

This zone is represented by small, rapidly dividing cells of the apical (apical) meristem located at the top of the growth cone. Such young cells are especially vulnerable, therefore, in order to protect the breeding zone, it covers the root cap. Its cells constantly die from contact with the soil, forming a mucous membrane that promotes root growth deep into the soil and reduces friction on the soil.

The root cap in cereal plants is formed from meristematic cells, the totality of which is called calyptrogen. Dicotyledonous plants have a dermatocalyptrogen, from which, in addition to the root cap, a protoderm develops, from which the rhizoderm (epiblema) further differentiates.

• Growth zone (stretching)

In this zone, the divided "young cells - grow up", gain cytoplasmic mass, increase in size. It is due to their growth that the root division zone is pushed deep into the soil, which ensures root growth.

• Suction zone

Here, cell differentiation occurs, the main types of tissues are formed. Rhizoderm cells (epiblema) form root hairs - a hair-like outgrowth. It is important to note that the root hair is an outgrowth of a single cell. However, there are a lot of cells, and together all their root hairs significantly increase the root absorption area. Growing into the soil, root hairs perform one of the most important functions of the root - the absorption of water and mineral salts dissolved in it from the soil solution. The length of the suction zone is 1-1.5 cm.

• Venue

As the root grows deep into the soil, the root hairs fall off, the once active suction zone now becomes another extremely important zone - conduction. In terms of length, the root conduction zone surpasses all others: it stretches up to the root collar - the place where the root passes into the stem, reaches tens of centimeters.

Dive (dive) of the root

This is the removal of the top of the main root along with the breeding zone. Thus, gardeners stop the growth of the main root and stimulate the development of lateral and adventitious roots, the root system is branched, and the plant gives a good harvest.

In the roots, the process of respiration takes place, just as in other organs. For normal growth and development, fresh air containing oxygen must be supplied to the root. With a poor soil structure, its saturation with water leads to a real oxygen starvation of the roots - asphyxia, and not all plants are resistant to this phenomenon. There are species that do not tolerate flooding at all and require good soil aeration - pedunculate oak, beech.

Note for yourself the importance of aerating the roots of the plant by looking at the following experiment. With the help of a pear on the left side of the picture, air is pumped into the water, partially dissolving in water - the roots receive oxygen, the plant develops. On the right, root respiration is difficult, plant development is slowed down, and if root asphyxia continues, the plant will die.

Root modifications

© Bellevich Yury Sergeevich 2018-2020

This article was written by Yury Sergeevich Bellevich and is his intellectual property. Copying, distribution (including by copying to other sites and resources on the Internet) or any other use of information and objects without the prior consent of the copyright holder is punishable by law. To obtain the materials of the article and permission to use them, please contact

Being underground and remaining absolutely invisible, the root forms entire systems that are directly dependent on the habitat. If necessary, the type can be modified to provide the plant with everything necessary for growth and development.

Root and its meaning

The root is the underground part of the plant. It securely holds the shoot in the ground. The length of the trunk of some trees can be several tens of meters, but even strong gusts of wind are not terrible.

The main function of the root is to absorb and transport water with nutrients dissolved in it. This is the only way to get the required amount of moisture into the plant.

Root types

According to the structural features, three types of roots are distinguished.

The main root of a plant is always one. In gymnosperms and angiosperms, it develops from the germinal root of the seed. It has lateral roots. They increase the absorbent surface area, allowing the plant to absorb the most water.

There are a lot of them directly from the shoot, they grow in a bunch. All types of roots have the same features of the internal structure. This element of the plant consists of forming a root cap, which protects the educational cells of the division zone from death. The elongation zone also consists of young, constantly dividing cells. Elements of conductive tissue and mechanical are in the zone of absorption and conduction. They make up the bulk of any kind of roots.

To provide the plant with the necessary amount of water, only one root is not enough for it. Therefore, different ones are combined, forming systems.

Rod and fibrous root system

The fibrous system is represented by adventitious roots. They are typical for representatives of the class Monocots - Lily and Onion. Anyone who has tried to pull a wheat shoot out of the ground knows that this is quite difficult to do. The bundle of adventitious roots grows strongly, occupies a large area, providing the plant with the necessary amount of nutrients. Bulbs of garlic or leeks, being also have developed adventitious roots, combined in

Consider the following type. The tap root system consists of two types of roots: main and lateral. The only main root is the stem and explains the name of this plant organ. It can penetrate deep into the soil, not only reliably holding its owner, but also extracting scarce moisture from the lower layers of the soil. A few tens of meters is not an obstacle for him.

The tap root system is characteristic of most angiosperms, since it is universal. The main root gets water from the depth, the lateral ones - from the topsoil.

Advantages

The tap root system is typical for plants growing in conditions of moisture deficiency. If there is no rain, the upper layers of the soil are dry, water can only be obtained deep from the ground. This function is performed by the main root. The tap root system is sometimes longer than the shoot itself. For example, a camel thorn about 30 cm high has a root more than 20 m long.

Lateral roots are also important. They increase the suction surface, sometimes occupying a significant area.

Which plants do not have a tap root system? Those that live in conditions of excessive moisture. Such plants simply do not need to get water from the depths. However, the tap root system significantly loses to the fibrous root system in terms of the total length of the roots.

Root modifications

The tap root system, the structure of which fully corresponds to the functions performed, is sometimes modified. The well-known carrot roots are thickened main roots. They store water and nutrients that allow plants to survive adverse environmental conditions. Such a modified tap root system is also characteristic of beets, radishes, radishes, and parsley.

Root crops are especially common in perennial and biennial plants. So, having sown carrot seeds in the spring, you can already get a harvest in the fall. But if the plant is left in the ground for the winter, then in the spring it will sprout again and give seeds. In a cold winter, carrots survive due to the thickened main root - the root crop. It allows you to hold out on stocks until the onset of heat.

The type of plant root system depends on the conditions in which it grows, and the characteristic features of the structure provide vital processes and increase the chances of survival in any climate and with any available amount of moisture and nutrients.

TAPROOT

TAPROOT, the first ROOT of the plant that develops from the PRIMARY ROOT. The taproot grows straight down and remains the main root of the plant, spreading lateral roots to expand the spread of the root system. In biennial plants, whose leaves and stems usually die off in the first winter, the root is kept alive underground, ready to sprout new leaves the following year. In some vegetable crops (such as beets, carrots and parsnips), the taproot develops into a fleshy organ - a root crop in which STARCH accumulates. These roots are edible for both animals and humans.

Scientific and technical encyclopedic dictionary.

See what "ROOT ROOT" is in other dictionaries:

The main main part of the root system of many plants, which is a direct continuation of the stem in the ground and develops from the original root of the seed germ. In some plants, as, for example, in oaks, the taproot or main root ... ...

A postmodern metaphor that captures the presumption of axiologically colored perception of depth, characteristic of classical metaphysics, as a symbol of the location of the essence and the source of the phenomenon rooted in it, which is associated with the interpretation ... ... History of Philosophy: Encyclopedia

See beginning, reason, origin uproot, take root... Dictionary of Russian synonyms and expressions similar in meaning. under. ed. N. Abramova, M .: Russian dictionaries, 1999. root, beginning, reason, origin; radical; spine, stem, ... ... Synonym dictionary

This term has other meanings, see Root (meanings) ... Wikipedia

Axial root, underground vegetative organ of higher plants, with unlimited growth in length and positive geotropism. The root fixes the plant in the soil and ensures the absorption and conduction of water with dissolved ... ... Wikipedia

Axial root, underground vegetative organ of higher plants, with unlimited growth in length and positive geotropism. The root fixes the plant in the soil and ensures the absorption and conduction of water with dissolved ... ... Wikipedia

Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

- (Radix). This part in most plants is expressed very clearly and differs well from the rest, but there are also many that are either completely devoid of K. or represent transitions to the stem and generally have non-typical K. Not to mention the lower, ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

rod- see rod; a / i, o / e. The tap root of a shrub. Rod / th question. Rod / th transformer (with rod) Mixture (used in the manufacture of rods) ... Dictionary of many expressions

The roots of a plant are its vegetative organs that are underground and conduct water and, accordingly, minerals to the rest, terrestrial, plant organs - stems, leaves, flowers and fruits. But the main function of the root is still to fix the plant in the ground.

On the distinctive features of root systems

Common in different root systems is that the root is always divided into main, lateral and adnexal. The main root, the root of the first order, always grows from the seed, it is he who is most powerfully developed and always grows vertically downwards.

Lateral roots depart from it and are called roots of the second order. They can branch, and adventitious roots, called third-order roots, depart from them. They (adventitious roots) never grow on the main, but in some plant species they can grow on stems and leaves.

This whole set of roots is called the root system. And there are only two types of root systems - rod and fibrous. And our main question concerns how the taproot and fibrous root systems differ.

The tap root system is characterized by the presence of a pronounced main root, while the fibrous root system is formed from adventitious and lateral roots, and its main root is not expressed and does not stand out from the total mass.

In order to better understand how the tap root system differs from the fibrous one, we propose to consider a visual diagram of the structure of one and the second systems.

Such plants as roses, peas, buckwheat, valerian, carrots, maple, birch, currants, watermelon have a tap root system. The urinary root system is found in wheat, oats, barley, onions and garlic, lilies, gladiolus and others.

Modified shoots underground

Many plants underground, in addition to the roots, have so-called modified shoots. These are rhizomes, stolons, bulbs and tubers.

Rhizomes grow mostly parallel to the soil surface, they are needed for vegetative propagation and storage. Outwardly, the rhizome looks like a root, but in its internal structure it has fundamental differences. Sometimes such shoots can come out of the ground and form a regular shoot with leaves.

Underground shoots are called stolons, at the end of which bulbs, tubers and rosette shoots are formed.

A bulb is a modified shoot, the storage function of which is carried out by fleshy leaves, and adventitious roots extend from a flat bottom below.

A tuber is a thickened shoot with axillary buds that performs the function of storage and reproduction.

root system name all the roots of a plant. It is formed by the main root, lateral roots and adventitious roots. The main root of the plant develops from the germinal root. Adventitious roots usually grow from the lower parts of the plant stem. Lateral roots develop on the main and adventitious roots.

The root system of plants performs two main functions.

First, it holds the plant in the soil. Secondly, the roots absorb the water and minerals that the plant needs from the soil.

If a plant develops a powerful main root, then a tap root system.

If the main root remains undeveloped or dies, and adventitious roots develop, then the plant develops fibrous root system.

The tap root system is characterized by a well-developed main root.

In appearance, it looks like a rod. The main root grows from the germinal root.

The tap root system is formed not only by the main root, but also by small lateral roots extending from it.

The tap root system is characteristic of many dicotyledonous plants.

A well-developed main root is found in beans, clover, sunflowers, carrots, and dandelions.

However, in many perennial plants with an original tap root system, sooner or later the main root dies off. Instead, numerous adventitious roots grow from the stem.

There is a subtype of the tap root system - branched root system.

In this case, several lateral roots get strong development. While the main root remains shortened. The type of branched root system is characteristic of many trees. Such a root system allows you to firmly hold the powerful trunk and crown of the tree.

The tap root system penetrates deeper into the soil than the fibrous root system.

Fibrous type of root system

The fibrous root system is characterized by the presence of many approximately identical adventitious horses, which form a kind of bundle.

Adventitious roots grow from the aboveground and underground parts of the stem, less often from the leaves.

Plants with a fibrous root system may also have a live main root. However, if it persists, it does not differ in size from the rest of the roots.

A fibrous root system is characteristic of many monocot plants. Among them are wheat, rye, onions, garlic, corn, potatoes.

Although the fibrous root system does not penetrate the soil as deeply as the tap root system, it occupies a larger area near the soil surface and braids the soil particles more densely, which improves the absorption of the aqueous solution.

Root systems and their classification. Types of root systems

Root changes:

A root crop is a thickened main root.

The main root and the lower part of the stem are involved in the formation of the root crop.

Most root plants are biennial. Root crops consist mainly of storage basic tissue (turnips, carrots, parsley).

Root tubers (root cones) are formed as a result of thickening of the lateral and adventitious roots.

With their help, the plant blooms faster.

Hook roots are a kind of adventitious roots. With the help of these roots, the plant "sticks" to any support.

Stilted roots - act as a support.

Plank roots are lateral roots that run at or above the soil surface, forming triangular vertical outgrowths adjacent to the trunk. Characteristic of the large trees of the tropical rainforest.

Aerial roots - lateral roots, grow in the aerial part.

They absorb rainwater and oxygen from the air. They are formed in many tropical plants in conditions of a lack of mineral salts in the soil of the tropical forest.

Mycorrhiza is the cohabitation of the roots of higher plants with fungal hyphae. With such a mutually beneficial cohabitation, called symbiosis, the plant receives water from the fungus with nutrients dissolved in it, and the fungus receives organic substances.

Mycorrhiza is characteristic of the roots of many higher plants, especially woody ones. Fungal hyphae, braiding thick lignified roots of trees and shrubs, act as root hairs.

Bacterial nodules on the roots of higher plants - the cohabitation of higher plants with nitrogen-fixing bacteria - are modified lateral roots adapted to symbiosis with bacteria.

Bacteria penetrate the root hairs into young roots and cause them to form nodules. In this symbiotic cohabitation, bacteria convert the nitrogen in the air into a mineral form available to plants.

And plants, in turn, provide bacteria with a special habitat in which there is no competition with other types of soil bacteria. Bacteria also use substances found in the roots of higher plants.

Most often, bacterial nodules are formed on the roots of plants of the legume family. In connection with this feature, legume seeds are rich in protein, and members of the family are widely used in crop rotation to enrich the soil with nitrogen.

Respiratory roots - in tropical plants - perform the function of additional respiration.

Types of root systems

In the tap root system, the main root is highly developed and clearly visible among other roots (typical for dicots).

A variety of tap root system - branched root system: consists of several lateral roots, among which the main root is not distinguished; characteristic of trees.

In the fibrous root system, in the early stages of development, the main root, formed by the germinal root, dies off, and the root system is composed of adventitious roots (typical for monocots). The tap root system usually penetrates deeper into the soil than the fibrous root system, however, the fibrous root system braids adjacent soil particles better.

Adventitious roots grow directly from the stem.

They grow from a bulb (which is a special stem) or from garden cuttings.

aerial roots. Roots that grow from the stem but do not penetrate the ground.

They are used by climbing plants for anchorage, as in ivy.

Supporting (stilted) roots.

A special type of aerial roots. They grow from the stem and then penetrate the ground, which may be covered with water. They support heavy plants such as mangroves.

Related information:

Site search:

What is the difference between a tap root system and a fibrous root system?

The roots of a plant are its vegetative organs that are underground and conduct water and, accordingly, minerals to the rest, terrestrial, plant organs - stems, leaves, flowers and fruits.

But the main function of the root is still to fix the plant in the ground.

On the distinctive features of root systems

Common in different root systems is that the root is always divided into main, lateral and adnexal.

The main root, the root of the first order, always grows from the seed, it is he who is most powerfully developed and always grows vertically downwards.

Lateral roots depart from it and are called roots of the second order. They can branch, and adventitious roots, called third-order roots, depart from them.

They (adventitious roots) never grow on the main, but in some plant species they can grow on stems and leaves.

This whole set of roots is called the root system. And there are only two types of root systems - rod and fibrous. And our main question concerns how the taproot and fibrous root systems differ.

The tap root system is characterized by the presence of a pronounced main root, while the fibrous root system is formed from adventitious and lateral roots, and its main root is not expressed and does not stand out from the total mass.

In order to better understand how the tap root system differs from the fibrous one, we propose to consider a visual diagram of the structure of one and the second systems.

Plants such as roses, peas, buckwheat, valerian, parsley, carrots, maple, birch, currants, watermelon have a tap root system.

The urinary root system is found in wheat, oats, barley, onions and garlic, lilies, gladiolus and others.

Modified shoots underground

Many plants underground, in addition to the roots, have so-called modified shoots. These are rhizomes, stolons, bulbs and tubers.

Rhizomes grow mostly parallel to the soil surface, they are needed for vegetative propagation and storage. Outwardly, the rhizome looks like a root, but in its internal structure it has fundamental differences.

Sometimes such shoots can come out of the ground and form a regular shoot with leaves.

Underground shoots are called stolons, at the end of which bulbs, tubers and rosette shoots are formed.

A bulb is a modified shoot, the storage function of which is carried out by fleshy leaves, and adventitious roots extend from a flat bottom below.

A tuber is a thickened shoot with axillary buds that performs the function of storage and reproduction.

Related articles:

superficial root system

Page 1

A surface root system is also formed in pine when dense heavy calcareous loam is shallow, and on such soils windfall of pine seed plants, and sometimes larch seed plants, is often observed. This phenomenon occurs, for example, in a number of places in the Plesetsk district of the Arkhangelsk region. On the Kola Peninsula (Murmansk region), the windfall of pine seedlings is expressed in places where crystalline rocks emerge on the day surface.

The surface root system of a pine, as we have already said, is also formed with a shallow occurrence of dense heavy carbonate loam. On such soils, pine seedlings, and sometimes larch seedlings, often fall out by the wind, for example, in some places in the Plesetsk district of the Arkhangelsk region.

On the Kola Peninsula (Murmansk region) and in North Karelia, windfall of pine seedlings occurs in places where crystalline rocks come to the day surface.

A surface root system with a weak development of vertically developing roots, only 0 5 - 1 m deep, is also formed by pine on sandy soils poor in moisture, where it can also fall out relatively easily from the wind.

Trees with a shallow root system are more susceptible to windblow, more weakened and more likely to die on the vine.

The disproportion between the increased transpiration after felling and the limited supply of moisture from the soil, as well as the rupture of small roots due to wind swaying of trees, lead to a decrease in growth immediately after felling on shallow, heavy, moist soils. On the contrary, trees on deep drained soils, where they form roots that go deep into the soil and are better provided with moisture, withstand changes in the situation relatively well and are able to increase their growth in diameter after 2-3 years, and sometimes immediately after felling.

These differences are reflected in the anatomical structure of the tree.

Trees with a shallow root system are more susceptible to windblow, more weakened and more likely to die on the root.

Damaged by the hooves of livestock, the surface root system of spruce is not able to resist honey agaric.

There are known facts of the impact of the wind, when from the windblow there are PTCs with weakened drainage, which form the surface root system of trees and are located on windbreak locations.

The windfall often develops in the NTC of spruce forests of accumulative slopes with rich moist loams, where spruce has a thin surface root system. The forest stand of the PTK of denudation slopes with clod-stone substrates is more wind-resistant, where spruce is firmly rooted in crevices of blocks.

Even a grassroots fire destroys thin-barked, with a crown falling low along the trunk, with a thinner surface root system, spruce and fir, and thus immediately removes two main obstacles to the emergence of self-seeding pine.

Old pine trees in any fires have a chance to survive due to a thicker bark, a highly raised crown and a root system that goes very deep into the soil; these old trees remain scattered as seed plants in greater or lesser numbers even after great fires.

After flowering, the plants are transplanted into wide and shallow pots or bowls, since azaleas have a superficial root system, pruning is carried out, removing weak, fattening shoots and pinching the tops of young shoots, stimulating their branching. Pinching is carried out in two or three steps, pinching shoots with three or four developed leaves. At the end of June, tweezing is stopped, since at this time the formation of next year's flower buds begins on the shoots.

Azaleas need moist air. During the period of active growth, from March to September, they are regularly sprayed with soft water. It is not recommended to spray during the flowering period to avoid the appearance of spots on the flowers. For normal flowering, high light intensity and top dressing with complex fertilizer are needed.

Weymouth pine is a relatively wind-tolerant species, but, like Scots pine, it can also produce a shallow root system, for example in shallow soils. Weymouth pine is no less sensitive to factory smoke than common pine.

Significant areas of underground structures, lined with a sufficient layer of earth, are planted with small groups of shrubs with a superficial root system, or perennials.

If necessary, decorative design on them arrange small rockeries. To avoid icing, planting of trees and shrubs is provided at a distance of at least 40 m from open sprinkler devices, and from cooling towers at a distance of at least 15 of their height.

Pages:      1    2    3    4

Root

The root performs the function of absorbing water from the soil with minerals. It fixes and holds the plant in the soil. Reserve nutrients can be deposited in the roots.

Root structure

The root is the axial organ of the plant, on which, unlike the stem, there are no leaves. The root grows in length throughout the life of the plant, moving through the solid particles of the soil. To protect the delicate tip of the root from mechanical damage and reduce friction, a root cap is used.

It is formed by thin-walled cells of the integumentary tissue, which exfoliate and form mucus, which facilitates the movement of the root in the soil. At the growing root, the cap is updated every day.

Under the root cap is a division zone. It is made up of educational fabric.

The cells of this tissue divide.

The resulting cells are stretched in the longitudinal direction and form a zone of stretching and growth. This ensures the growth of the root in length. The cells of the educational tissue form other tissues - integumentary, conductive and mechanical.

The stretch zone is followed by the suction zone.

In this zone, a lot of root hairs are formed from the cells of the integumentary tissue. Wheat, for example, has up to 100 per 1 mm2 of root surface. Thanks to the root hairs, the absorptive surface of the root increases tens and even hundreds of times. Root hairs work like tiny pumps that suck water from the soil with minerals dissolved in it. The suction zone is mobile, it changes its place in the soil depending on the growth of the root. Root hairs live for several days, and then die off, and a suction zone appears on the newly growing root area.

Therefore, the absorption of water and nutrients always occurs from a new volume of soil.

In place of the former suction zone, a conduction zone is formed. Through the cells of this zone, water and minerals are carried upwards, to the above-ground organs, and organic substances are carried downwards, from the leaves to the roots.

Cells of the integumentary tissue of the conduction zone in adult plants, when dying, can overlap each other, forming a plug. As a result, the adult root becomes woody.

The conduction zone accounts for most of the length of long-lived roots.

Types of root systems

The totality of all the roots of a plant is called the root system. There are two types of root systems - rod and fibrous.

In the tap root system, the main root is isolated.

It grows strictly downward and stands out among other roots with greater length and thickness. Lateral roots extend from the main root. The tap root system is characteristic of peas, sunflowers, shepherd's purse, dandelions and many other plants.

The fibrous root system is characteristic of cereals, plantain and other plants in which the main root stops growing immediately at the beginning of embryo development.

At the same time, numerous roots are formed at the base of the shoot, which are called adventitious.

The plant develops a bundle, or lobe, of more or less equal in thickness, length and branching of adventitious roots.