Plants that have a taproot system. Root and root systems. Modified shoots underground

TAPROOT

TAPROOT, the first ROOT of a plant that develops from a PRIMARY ROOT. The taproot grows straight down and remains the main root of the plant, spreading out 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 called a root vegetable in which STARCH accumulates. Such root vegetables are edible for both animals and humans.

Scientific and technical encyclopedic dictionary.

See what "ROD 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 embryo. Some plants, such as oak trees, have a tap or main root ... ...

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

See the beginning, the reason, the origin to uproot, put down roots ... Dictionary of Russian synonyms and expressions similar in meaning. under. ed. N. Abramova, M .: Russian dictionaries, 1999. root beginning, reason, origin; radical; spine, core, ... ... 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

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

- (Radix). This part in most plants is very clearly expressed 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 ones, ... ... Encyclopedic Dictionary of F.A. Brockhaus and I.A. Efron

pivotal- see the rod; a / i, o / e. Pivot / th root of the bush. Rod / th question. Rod / th transformer (with rod) Mixed mixture (used in the manufacture of rods) ... Dictionary of many expressions

Root- the main vegetative organ of a plant, which, in a typical case, performs the function of soil nutrition. The root is an axial organ with radial symmetry and growing in length indefinitely due to the activity of the apical meristem. It differs from the shoot morphologically in that leaves are never formed on it, and the apical meristem is always covered with a root cap.

In addition to the main function of absorbing substances from the soil, the roots also perform other functions:

1) the roots strengthen ("anchor") the plants in the soil, make it possible to grow vertically and take the shoots up;

2) various substances are synthesized in the roots, which then move to other plant organs;

3) reserve substances can be deposited in the roots;

4) the roots interact with the roots of other plants, microorganisms, fungi that live in the soil.

The set of roots of one individual forms a single one in morphological and physiological terms root system.

Root systems include roots of various morphological nature - main root, lateral and clauses roots.

Main root develops from the embryonic root. Lateral roots are formed on the root (main, lateral, subordinate), which in relation to them is denoted as maternal... They arise at some distance from the apex, in the direction from the base of the root to its apex. Lateral roots are laid endogenously, i.e. in the internal tissues of the maternal root. If branching took place in the apex itself, it would make it difficult for the root to advance in the soil. Adventitious roots can occur on stems, leaves, and roots. In the latter case, they differ from lateral roots in that they do not show a strict order of origin near the apex of the maternal root and can arise in old root areas.

By origin, the following types of root systems are distinguished ( rice. 4.1):

1) main root system represented by the main root (first order) with lateral roots of the second and subsequent orders (in many shrubs and trees, most dicotyledonous plants);

2)adventitious root system develops on stems, leaves; found in most monocotyledonous plants and many dicotyledonous plants propagating vegetatively;

3)mixed root system formed by the main and adventitious roots with their lateral branches (many herbaceous dicotyledons).

Rice. 4.1. Types of root systems: A - main root system; B - system of adventitious roots; C - mixed root system (A and B - tap root systems; B - fibrous root system).

Distinguish in form pivotal and fibrous root systems.

V pivotal the root system, the main root is highly developed and clearly visible among the rest of the roots. V fibrous the root system, the main root is invisible or not, and the root system is composed of numerous adventitious roots ( rice. 4.1).

The root has potentially unlimited growth. However, under natural conditions, the growth and branching of roots is limited by the influence of other roots and soil environmental factors... The bulk of the roots is located in the upper soil layer (15 cm), the richest in organic matter. The roots of trees deepen by an average of 10-15 m, and in width they usually extend beyond the radius of the crowns. The root system of maize goes to a depth of about 1.5 m and about 1 m in all directions from the plant. A record depth of root penetration into the soil was noted in the desert mesquite shrub - more than 53 m.

One rye bush grown in a greenhouse had a total root length of 623 km. The total growth of all roots in one day was approximately 5 km. The total area of all roots in this plant was 237 m 2 and was 130 times larger than the surface of the aboveground organs.

Zones of young root end - these are parts of a young root different in length, performing different functions and characterized by certain morphological and anatomical features ( rice. 4.2).

The root tip is always covered from the outside root cap protecting the apical meristem. The cap consists of living cells and is constantly renewed: as old cells slough off from its surface, the apical meristem forms new young cells to replace them from the inside. The outer cells of the root cap peel off while still alive, they produce abundant mucus, which facilitates the movement of the root among the solid particles of the soil. The cells of the central part of the cap contain many starch grains. Apparently, these grains serve statoliths, i.e., they are able to move in the cell when the position of the root tip in space changes, due to which the root always grows in the direction of the action of gravity ( positive geotropism).

Under the cover is division zone, represented by the apical meristem, as a result of the activity of which all other zones and root tissues are formed. The division zone is about 1 mm in size. The cells of the apical meristem are relatively small, multifaceted, with dense cytoplasm and a large nucleus.

Following the division zone is stretch zone, or growth zone... In this zone, the cells almost do not divide, but strongly stretch (grow) in the longitudinal direction, along the axis of the root. The cell volume increases due to the absorption of water and the formation of large vacuoles, while the high turgor pressure pushes the growing root between the soil particles. The extension of the stretch zone is usually small and does not exceed a few millimeters.

Rice. 4.2. General view (A) and longitudinal section (B) of the root end (scheme): I - root cap; II - division and extension zones; III - suction zone; IV - the beginning of the zone of conduction: 1 - growing lateral root; 2 - root hairs; 3 - rhizoderm; 3а - exoderm; 4 - primary cortex; 5 - endoderm; 6 - pericycle; 7 - axial cylinder.

Next comes absorption zone, or suction zone... In this zone, the integumentary tissue is rhizoderm(epible), whose cells carry numerous root hairs... Root stretching stops, root hairs tightly cover soil particles and, as it were, grow together with them, absorbing water and mineral salts dissolved in it. The absorption zone extends up to several centimeters. This zone is also called zone of differentiation, since this is where the formation of permanent primary tissues occurs.

The lifespan of the root hair does not exceed 10-20 days. Above the suction zone, where root hairs disappear, zone... Through this part of the root, water and salt solutions absorbed by the root hairs are transported to the overlying organs of the plant. Lateral roots are formed in the conduction area (fig. 4.2).

The cells of the suction and conduction zones occupy a fixed position and cannot move relative to the soil areas. However, the zones themselves, due to the constant apical growth, continuously move along the root as the root end grows. Young cells from the side of the stretch zone are constantly included in the absorption zone, and at the same time aging cells are excluded, passing into the composition of the conduction zone. Thus, the root suction apparatus is a mobile formation that continuously moves in the soil.

In the same way consistently and regularly in the root end, internal tissues arise.

Primary root structure. The primary structure of the root is formed as a result of the activity of the apical meristem. The root differs from the shoot in that its apical meristem deposits cells not only inward, but also outward, replenishing the cap. The number and location of initial cells in root apexes vary considerably in plants belonging to different taxonomic groups. Derivatives of initials, already near the apical meristem, differentiate into primary meristems – 1) protoderm, 2) main meristem and 3) procambium(rice. 4.3). Three tissue systems are formed from these primary meristems in the absorption zone: 1) rhizoderm, 2) primary cortex and 3) axial (central) cylinder, or stele.

Rice. 4.3. Longitudinal section of the tip of the onion root.

Rhizoderma (epible, root epidermis) - suction tissue formed from protoderm, the outer layer of the primary root meristem. Functionally, rhizoderm is one of the most important plant tissues. Through it, water and mineral salts are absorbed, it interacts with the living population of the soil, substances that help soil nutrition are released from the root into the soil through the rhizoderm. The absorbing surface of the rhizoderm is greatly increased due to the presence of tubular outgrowths in some of the cells - root hairs(fig.4.4). The hairs are 1–2 mm long (up to 3 mm). One four-month-old rye plant had approximately 14 billion root hairs with an absorption area of 401 m2 and a total length of more than 10,000 km. In aquatic plants, root hairs may be missing.

The hair wall is very thin and consists of cellulose and pectin substances. Its outer layers contain mucus, which contributes to the establishment of closer contact with soil particles. The mucus creates favorable conditions for the settlement of beneficial bacteria, affects the availability of soil ions and protects the root from drying out. Physiologically, rhizoderm is highly active. It absorbs mineral ions with the expenditure of energy. The hyaloplasm contains a large number of ribosomes and mitochondria, which is characteristic of cells with a high level of metabolism.

Rice. 4.4. Cross section of the root in the suction zone: 1 - rhizoderm; 2 - exoderm; 3 - mesoderm; 4 - endoderm; 5 - xylem; 6 - phloem; 7 - pericycle.

From main meristem formed primary cortex... The primary root bark is differentiated into: 1) exoderm- the outer part, lying directly behind the rhizoderma, 2) the middle part - mesoderm and 3) the innermost layer - endoderm (rice. 4.4). The bulk of the primary crust is mesoderm formed by living parenchymal cells with thin walls. The cells of the mesoderm are loosely located, gases necessary for cell respiration circulate along the intercellular system along the root axis. In marsh and aquatic plants, the roots of which lack oxygen, the mesoderm is often represented by aerenchyma. Also, mechanical and excretory tissues may be present in the mesoderm. The parenchyma of the primary cortex performs a number of important functions: it participates in the absorption and conduction of substances, synthesizes various compounds, and spare parts are often deposited in the cells of the cortex. nutrients but, for example, starch.

The outer layers of the primary cortex, underlying the rhizoderm, form exoderm... The exoderm arises as a tissue that regulates the passage of substances from the rhizoderm to the cortex, but after the rhizoderm dies off above the absorption zone, it appears on the root surface and turns into a protective integumentary tissue. The exoderm is formed as a single layer (less often several layers) and consists of living parenchymal cells tightly closed together. As the root hairs die off, the cell walls of the exoderm are covered from the inside with a layer of suberin. In this respect, the exoderm is similar to a cork, but unlike it, it is primary in origin, and the cells of the exoderm remain alive. Sometimes in the exoderm there are permeable cells with thin non-corked walls, through which selective absorption of substances occurs.

The innermost layer of the primary cortex - endoderm... It surrounds the stele in the form of a continuous cylinder. Endoderm in its development can go through three stages. At the first stage, its cells are tightly adjacent to each other and have thin primary walls. On their radial and transverse walls, thickenings in the form of frames are formed - Caspari belts (rice. 4.5). The belts of neighboring cells are closely interconnected, so that they are created around the stele. continuous system... Suberin and lignin are deposited in the Caspari belts, which makes them impermeable to solutions. Therefore, substances from the cortex to the stele and from the stele to the cortex can only pass through the symplast, that is, through the living protoplasts of the endoderm cells and under their control.

Rice. 4.5. Endoderm at the first stage of development (diagram).

At the second stage of development, suberin is deposited along the entire inner surface of endoderm cells. At the same time, some cells retain their primary structure. it passage cells, they remain alive, and through them a connection is made between the primary cortex and the central cylinder. As a rule, they are located opposite the rays of the primary xylem. In roots that do not have a secondary thickening, the endoderm can acquire a tertiary structure. It is characterized by a strong thickening and lignification of all walls, or more often the walls facing outward remain relatively thin ( rice. 4.7). The passage cells are also preserved in the tertiary endoderm.

Central(axial) cylinder, or stele formed in the center of the root. Already close to the division zone, the outermost layer of the stele forms pericycle, whose cells retain the character of the meristem and the ability to form neoplasms for a long time. In a young root, the pericycle consists of one row of living parenchymal cells with thin walls ( rice. 4.4). The pericycle has several important functions. In most seed plants, lateral roots are laid in it. In species with secondary growth, it participates in the formation of cambium and gives rise to the first phellogen layer. In the pericycle, the formation of new cells often occurs, which are then included in its composition. In some plants, the rudiments of adventitious buds also appear in the pericycle. In old roots of monocotyledonous plants, pericycle cells are often sclerified.

There are cells behind the pericycle procambia which differentiate into primary conductive tissues. Phloem and xylem elements are laid in a circle, alternating with each other, and develop centripetally. However, xylem usually overtakes phloem in its development and occupies the center of the root. In the cross section, the primary xylem forms a star, between the rays of which there are phloem areas ( rice. 4.4). This structure is called radial conductive beam.

A xylem star can have a different number of rays - from two to many. If there are two, the root is called diarchic if three - triarchic, four - tetrarch, and if a lot - polyarchic (rice. 4.6). The number of xylem rays usually depends on the thickness of the root. In thick roots of monocotyledonous plants, it can reach 20-30 ( rice. 4.7). In the roots of one and the same plant, the number of xylem rays can be different, in thinner branches it is reduced to two.

Rice. 4.6. Types of structure of the axial cylinder of the root (diagram): A - diarchic; B - triarchic; B - tetrarch; D - polyarchic: 1 - xylem; 2 - phloem.

The spatial separation of the strands of the primary phloem and xylem, located at different radii, and their centripetal origin are characteristics structures of the central cylinder of the root and are of great biological importance. The elements of the xylem are as close as possible to the surface of the stele, and solutions coming from the bark can more easily penetrate into them, bypassing the phloem.

Rice. 4.7. Monocotyledon root cross section: 1 - the remains of the rhizoderm; 2 - exoderm; 3 - mesoderm; 4 - endoderm; 5 - access cells; 6 - pericycle; 7 - xylem; 8 - phloem.

The central part of the root is usually occupied by one or several large xylem vessels. The presence of a core is generally atypical for the root, however, in the roots of some monocots, in the middle there is a small area of mechanical tissue ( rice. 4.7) or thin-walled cells arising from procambium (fig.4.8).

Rice. 4.8. A cross section of a corn root.

The primary root structure is characteristic of young roots of all plant groups. In spore and monocotyledonous plants, the primary structure of the root remains throughout life.

Secondary root structure. In gymnosperms and dicotyledonous plants, the primary structure does not last long and above the absorption zone is replaced by a secondary one. Secondary root thickening occurs due to the activity of secondary lateral meristems - cambia and phellogena.

Cambium arises in the roots from meristematic procambial cells in the form of an interlayer between the primary xylem and phloem ( rice. 4.9). Depending on the number of phloem strands, two or more zones of cambial activity are formed simultaneously. At first, the cambial layers are separated from each other, but soon the pericycle cells lying opposite the xylem rays divide tangentially and join the cambium into a continuous layer surrounding the primary xylem. Cambium lays in layers secondary xylem (wood) and out secondary phloem (bast). If this process takes a long time, then the roots reach a considerable thickness.

Rice. 4.9. Establishment and initiation of cambium activity at the root of a pumpkin seedling: 1 - primary xylem; 2 - secondary xylem; 3 - cambium; 4 - secondary phloem; 5 - primary phloem; 6 - pericycle; 7 - endoderm.

The sections of the cambium arising from the pericycle consist of parenchymal cells and are not capable of depositing elements of conductive tissues. They form primary pith rays, which are wide areas of the parenchyma between secondary conductive tissues ( rice. 4.10). Secondary core, or bast-wood beams occur additionally with prolonged root thickening, they are usually narrower than the primary ones. The pith rays provide a connection between the xylem and the phloem of the root; radial transport of various compounds occurs along them.

As a result of cambium activity, the primary phloem is pushed outward and compressed. The star of the primary xylem remains in the center of the root, its rays can persist for a long time ( rice. 4.10), but more often the center of the root is filled with a secondary xylem, and the primary xylem becomes invisible.

Rice. 4.10. Cross section of pumpkin root (secondary structure): 1 - primary xylem; 2 - secondary xylem; 3 - cambium; 4 - secondary phloem; 5 - primary core beam; 6 - cork; 7 - parenchyma of the secondary cortex.

The tissues of the primary cortex cannot follow the secondary thickening and are doomed to death. They are replaced by a secondary integumentary tissue - peridermis, which can stretch on the surface of the thickening root due to the work of phellogen. Phellogen is laid in the pericycle and begins to lay out plug, and inside - phelloderm... The primary cortex, cut off by a cork from internal living tissues, dies off and is discarded ( rice. 4.11).

Phelloderm cells and parenchyma, formed by division of pericycle cells, form parenchyma of the secondary cortex surrounding conductive tissue (fig.4.10). Outside, the roots of the secondary structure are covered with periderm. The crust is rarely formed, only on old tree roots.

The perennial roots of woody plants are often strongly thickened as a result of long-term cambium activity. The secondary xylem in such roots merges into a solid cylinder, surrounded on the outside by a cambium ring and a solid ring of secondary phloem ( rice. 4.11). Compared to the stem, the boundaries of the annual rings in the root wood are much less pronounced, the bast is more developed, the core rays are, as a rule, wider.

Rice. 4.11. A cross-section of a willow root at the end of the first growing season.

Root specialization and metamorphosis. Most plants in the same root system have distinctly different growth and sucking endings. Growth ends are usually more powerful, lengthen quickly and move deeper into the soil. The stretch zone in them is well expressed, and the apical meristems work vigorously. Sucking endings, which appear in large numbers on growth roots, lengthen slowly, and their apical meristems almost stop working. The sucking endings seem to stop in the soil and intensively "suck" it.

In woody plants, thick skeletal and semi-skeletal roots on which short-lived root lobes... The root lobes, which are continuously replacing each other, include growth and sucking endings.

If the roots perform special functions, their structure changes. A sharp, hereditarily fixed organ modification caused by a change in functions is called metamorphosis... Root modifications are very diverse.

The roots of many plants form a symbiosis with the hyphae of soil fungi, called mycorrhiza("Mushroom root"). Mycorrhiza forms on sucking roots in the absorption zone. The fungal component makes it easier for the roots to obtain water and mineral elements from the soil, often fungal hyphae replace root hairs. In turn, the fungus receives carbohydrates and other nutrients from the plant. There are two main types of mycorrhiza. Hyphae ectotrophic mycorrhiza form a cover that envelops the root from the outside. Ectomycorrhiza is widespread in trees and shrubs. Endotrophic mycorrhiza occurs mainly in herbaceous plants... Endomycorrhiza is located inside the root, hyphae are introduced into the cells of the crustal parenchyma. Mycotrophic nutrition is very widespread. Some plants, for example orchids, cannot exist at all without symbiosis with fungi.

On the roots of legumes arise special education – nodules in which bacteria from the genus Rhizobium settle. These microorganisms are able to assimilate atmospheric molecular nitrogen, converting it into a bound state. Some of the substances synthesized in nodules are assimilated by plants, bacteria, in turn, use substances in the roots. This symbiosis is of great importance to agriculture. Legumes are rich in proteins due to their additional nitrogen source. They provide valuable food and feed products and enrich the soil with nitrogenous substances.

Very widespread storing roots. They are usually thickened and heavily parenchyma. Strongly thickened adventitious roots are called root cones, or root tubers(dahlia, some orchids). Many, more often biennial, plants with a taproot system develop a formation called root vegetable... Both the main root and the lower part of the stem are involved in the formation of the root crop. In carrots, almost the entire root crop is composed of the root, in turnips, the root forms only the lowest part of the root crop ( rice. 4.12).

Figure 4.12. Root vegetables of carrots (1, 2), turnips (3, 4) and beets (5, 6, 7) ( xylem is black on cross sections; the horizontal dotted line shows the border of the stem and root).

Root crops of cultivated plants have arisen as a result of long-term selection. In root crops, the storage parenchyma is highly developed and mechanical tissues have disappeared. In carrots, parsley, and other umbrella parenchyma, the parenchyma is strongly developed in the phloem; in turnips, radishes and other crucifers, in the xylem. In beets, reserve substances are deposited in the parenchyma formed by the activity of several additional layers of cambium ( rice. 4.12).

Many bulbous and rhizome plants form retractors, or contractile roots ( rice. 4.13, 1). They can shorten and retract the shoot into the soil to the optimum depth during summer drought or winter frost. Retracting roots have thickened bases with transverse rugosity.

Rice. 4.13. Root metamorphosis: 1 - corms of gladiolus with retracting roots thickened at the base; 2 - respiratory roots with pneumatophores in Avicennia ( NS- tide zone); 3 - orchid aerial roots.

Rice. 4.14. Part of a cross-section of an aerial root of an orchid: 1 - velamen; 2 - exoderm; 3 - access cage.

Respiratory roots, or pneumatophores (rice. 4.13, 2) are formed in some tropical woody plants living in conditions of a lack of oxygen (taxodium, or marsh cypress; mangrove plants living along the marshy shores of the ocean coasts). Pneumatophores grow vertically upward and protrude above the soil surface. Through a system of holes in these roots associated with aerenchyma, air enters the underwater organs.

In some plants, to maintain shoots in the air, additional supporting roots. They move away from the horizontal branches of the crown and, having reached the soil surface, branch intensively, turning into columnar formations that support the crown of the tree ( columnar banyan roots) ( rice. 4.15, 2). Stilted the roots extend from the lower portions of the stem, giving the stem stability. They are formed in mangrove plants, plant communities developing on tropical oceans flooded at high tide ( rice. 4.15, 3), as well as in corn ( rice. 4.15, 1). Ficus rubbery forms board-like roots. Unlike columnar and stilted, they are not adventitious in origin, but lateral roots.

Rice. 4.15. Support roots: 1 - stilted corn roots; 2 - pillar-shaped banyan roots; 3 - stilted roots of rhizophora ( NS- tide zone; from- low tide zone; silt- the surface of the muddy bottom).

The root system is very important for plant growth and development. Support, water extraction and nutrition are the functions that it performs. To understand how to properly plant and grow trees, shrubs, cultivated plants, you need to know how the roots are arranged. If you see that the planted crops grow poorly on one bed, and trees or shrubs are planted next to the bed, perhaps they are oppressing your plantings with their roots.

The roots of the plants did not appear immediately. Plants have gone through an evolutionary path, as a result of which they acquired roots. Algae do not have roots, since they live in water and they do not need roots. The first plants that took root on the ground did not have roots, but the so-called resoids, which served only for anchoring in the soil. Now resoids have some types of mosses. The root is the main part of the entire plant system. It keeps the plant in the ground. Throughout its life, the root provides moisture and nutrition. Root development depends on climatic conditions. For example, many desert plants have a long root to extract water.

There are two types of root systems - pivotal and root.

In the tap root system, the main root is pronounced, thicker, lateral roots extend from it.

The fibrous root system is characterized by the absence of the main root, growth occurs due to the lateral and adventitious roots, does not penetrate into the ground as deeply as the pivotal one.

All horse systems consist of

main root
lateral roots
adventitious roots

All of these roots form a root system that forms throughout the life of the plant. The main root develops from the embryo, which grows vertically in the ground. Lateral roots extend from it.

Features of plant root systems

Roots adapt to environmental conditions. Corn roots grow 2 meters in diameter, apple roots 15 meters in diameter. Knowing the structure of the root system is very important for the gardener in order to determine what kind of care the plant needs. If you have an understanding of the location of the roots, you can properly care for the plant so as not to damage the roots.

Loose soils promote root penetration deep into the ground. Soils in which the percentage of oxygen is low and with a dense structure are close to the development of roots to the soil surface.

Thistle is a common weed that penetrates the soil up to six meters.

Plants that grow in the desert have long roots. This is due to the deep location of groundwater.

The length of the roots of the barnyard is 15 meters.

If the root system in plants is poorly developed, the leaves absorb moisture from the fog, with the help of stems and leaves.

There are plants that retain moisture in all parts - stems and leaves. Such plants have a root system that has the ability to absorb and store rainwater. They are common where the heat gives way to active rains. Such plants include cacti, succulents. Their roots are poorly developed.

Plants capable of reducing water loss, their roots, top covered with cork. They are able to retain water in preparation for water scarcity. They have elastic leaves to avoid mechanical damage when water is lost. These plants include:

sand acacia

aristide

Plants in which the growing season lasts only during favorable periods of time when it rains. Their life cycle short. These include plants with tubers and bulbs.

Plants whose roots are highly developed for water extraction. Their root system is very well developed, spreading in the soil to absorb as much water as possible. Cutter, sage, wild watermelon belong to this type of plant.

In nature, there are aerial roots that extract moisture from the air. These plants include the orchid.

There are plants with mixed root systems. These include cabbage, plantain, sunflower, tomatoes. These are the plants that spud. For the development of roots, except natural conditions a person influences by hilling and diving. For the development of lateral roots, the tip of the main root is pinched off. Hilling - adding soil to the plant.

Plants with a fibrous root system

Heavy types of soils, with the occurrence of groundwater close to the surface, slopes - these conditions are characteristic of the development of plants with a fibrous system: birch, maple, chestnut, linden, larch, alder, fir, yew, apple tree. plantain, sunflower.

Cereal crops - rye, wheat, barley - have a fibrous root system. The roots of cereals go deep into the soil, up to 2 meters.

The apple tree root system has horizontal and vertical roots. Air and batteries are supplied to the horizontal roots. Vertical - keep the tree in the soil and extract water and food from the deeper layers of the earth. In addition, the apple tree has another root classification - skeletal and overgrown (fibrous) roots. The overgrowing roots are close to the surface, up to 50 cm, so fertilization is very effective.

When the bark of a tree is damaged, the root system is inhibited.

The birch has a very powerful root system, but it does not go deep into the ground. At the beginning of growth, the birch grows slowly until the main root dies off. After that, the birch starts growing faster, lateral roots begin to grow. Birch loves moisture very much, its roots absorb all the moisture around them, therefore there is so little vegetation around the birch.

The onion root system also refers to the fibrous and is considered very weak. This determines its increased requirement for the soil, especially at the stage of seed germination.

Leek root system

Onion

The fibrous root system is:

Marigold

Sansiveria

Fatshedera

Tap root plants

In plants with a rod system, the root consists of a rod-root and lateral roots extending from it.

These plants adapt to getting water from the depths of the earth. The main root of some plants can extend into the ground for several tens of meters. In dry areas or in conditions where it rains little plants are characterized by a pivotal root system. For example, carrots have a thick main root in which they store moisture and nutrients in preparation for what may be a rainless summer. Beets, radishes, radishes, parsley root - the root system is the same. This adaptation of the roots increases the plant's chances of survival. Carrots can be planted in winter, they survive due to their thick roots.

What the root system does

As mentioned above, the root is the main part of the plant that provides nutrition and growth. From the roots, water and nutrients move upward to the stems and leaves. To properly care for a particular plant, you need to know its features and growing conditions. If you properly water and feed trees, shrubs, garden plants and flowers, success in growing is guaranteed.

The mangrove tree has roots called stilted roots. They absorb moisture from the atmosphere and are able to resist breaking waves.

Root system of nightshade plants

Solanaceae are plant species that grow all over the globe. About 3000 species are known. It includes herbs, shrubs, vegetables, both edible and poisonous. They are united by the structure of vegetative organs and inflorescences. Their fruits are berries or capsules. They make medicines from nightshades, eat them, feed animals, make cigarettes.

Nightshade crops include popular vegetables such as tomatoes, eggplants, potatoes, and peppers. From flowers - petunia, fragrant tobacco, medicinal plants- belladonna belladonna.

In tomatoes, the root system goes into the ground to a depth of one and a half meters. With a not very deep bedding of groundwater, they easily extract water for themselves. Eggplant has strong branching roots, going into the soil to a depth of half a meter.

In potatoes, root crops are eaten, so it is so important how much the horse system will be developed. The roots of potatoes are within the arable layer, only some roots go deep. Edible tubers are the thickening of the apical shoots. They accumulate a supply of organic substances, mainly starch. Hilling is an important procedure in potato care.

In pepper, on well-drained soils, the roots occupy a volume in the upper layer with a diameter of up to one meter. They can go 50 cm deep.

The roots of petunia are very powerful, development at the beginning of growth is slow. One plant requires at least five liters of soil. They thrive in nutritious soils.

Root system of flowering plants

All flowering plants are divided into trees, grasses and shrubs. They are also called angiosperms, since the seed grows inside until it breaks through the shell. In total, there are 250,000 species of them on earth. The root system is both fibrous and pivotal. The classes of flowering plants are monocotyledonous and dicotyledonous. More on this in the section below. The class of dicotyledons has almost everyone at home in the form of potted flowers - ficuses, violets, cacti. Among garden plants - all rosaceous, nightshade, moth, cruciferous, Compositae. Trees that are classified as flowering have different heights. For example, cherry is a short tree. But the eucalyptus can reach 100 meters in height.

Shrubs:

gooseberry

currant

and even hazel and lilac.

Herbs:

Dandelion

Among the diverse representatives there are annuals, biennials and perennials. In biennials and perennials, the roots accumulate food and energy for wintering. In annuals, the roots die with the flower.

Root system of legumes

Legumes include well-known beans, peas, peanuts, chickpeas, beans. There are woody forms - acacia, mimosa. Herbs - clover, lupine. They meet both in wildlife and in the gardens of gardeners. Cultivation is also practiced on an industrial scale. The root system of legumes is pivotal. Most of them have small tubers on the roots, which are formed as a result of the activity of bacteria that penetrate from the soil into the roots. These bacteria use nitrogen and convert it into minerals that other plants feed on. Therefore, legumes are useful to plant next to other plants. After the death of the plant, the soil is saturated with nitrogen and more fertile.

What you need to do to strengthen the root system of a plant

Since the root system plays a large role in the life of plants, it is important to monitor its correct development. There are many ways to grow and develop roots. They are subdivided into phytohormones - extract from plants, humates - extract from humus, improved by additives. and natural - folk remedies.

Popular among gardeners - root, kornerost, heteroauxin, pollen, ovosil.

Epin - has a positive effect on all parts of the plant.

Folk remedies are also widely used to strengthen the roots of plants. This is honey, yeast, aloe.

There is a close relationship between the root system and part of the aboveground plant. Optimal root nutrition leads to the development of a successful plant.

Root system of dicotyledonous plants

Dicotyledonous plants have a root system. In nature, this is the most numerous class, which has 180 thousand species and makes up 75 percent of flowering plants. Nutrients are located in the endosperm and in the embryo. The leaf venation is pronounced, the leaf plate is dissected by veins. The embryo allows the main root to develop well. Many plants have a layer of cambium through which the plant takes on a lignified form.

Cambium is a cell layer that is parallel to the surface of stems and roots. Due to it, the thickening of the stem occurs.

Dicotyledonous plants include

spicy herbs - parsley, dill, laurel, coriander, anise, allspice.
Umbrella, a characteristic feature of which is an inflorescence in the form of an umbrella. These are cow parsnip, carrots, coriander, snow, fennel, hemlock, etc.
Rosaceae - raspberries, apple trees, plums, cherries, irga, apricots, cherries, almonds, etc.
Compositae - marigolds, chamomile, daisy, dandelion, dahlia, sunflower, etc.

Root system of monocotyledonous plants

Depending on which class the plants belong to, the type of root system is determined.

Monocotyledonous plants have a fibrous root system. They have one cotyledon in the bud.

The cotyledon is the inner part of the seed that contains the embryo - the embryo.

Nutrients are found in the endosperm. The embryo root is very poorly developed. When the grain germinates, adventitious roots extend from it. Leaf venation is parallel or arched, for example, lily of the valley, leeks, barley, wheat. The leaf is poorly developed and is a leaf sheath.

Monocotyledonous plants include water and weeds, pineapple, lily of the valley, calla lilies, monstera, tulip, lily, hyacinth, bulbous, etc.

Plant root system types

Root system of fruit trees

The root system of the fruit tree keeps it in the soil, absorbs moisture and nutrients, forms organic compounds - amino acids and proteins, promotes the development of microorganisms that are beneficial to the plant. The roots of a fruit tree are horizontal and vertical. Horizontal roots play an important role, as they absorb moisture and nutrition from the surface. Their volume in diameter corresponds to the size of the crown, or exceeds it. Therefore, watering and fertilization is so important. The ratio of vertical and horizontal roots depends on many things - soil fertility, rootstock, care. If the soil is fertile and fertilization is sufficient, horizontal roots develop well. On dry and nutritionally poor soils, vertical roots grow, which go deep into the soil to get food and water. Stone fruit crops are not deeply rooted. Root growth usually occurs during the growing season of the tree. With the help of modern methods, which are developed by agricultural technicians, the growth of roots can be regulated.

Root system of berry bushes

Berry bushes play a special role in fruit orchards. Knowledge of the structure of their root system and proper care ensure a good harvest. Their main difference from trees is the absence of a trunk. Dozens of branches branch off from the roots, which give a crop. The roots do not lie deep, their horizontal arrangement is characteristic. When digging a near-trunk circle, you need to carefully work with a shovel to avoid touching the roots.

Water in plant life

Water plays an important role in the life of every plant.

Plants are 80 percent water
Delivers food to other parts of the plant
Regulates heat transfer
A source of hydrogen for photosynthesis.
Provides firmness to the leaves

Taking into account all the factors of the role of water, its absence will ensure the death of the plant. The entry of water into the plant's body comes from the roots, the evaporation of water occurs through the leaves. The meaning of such a water cycle is metabolism. If the uptake of water by the roots is less than its input through the leaves, the plant wilts. Water replenishment occurs at night, as evaporation is reduced.

Water exchange takes place in three stages:

The roots absorb water.
The water is moving towards the top.
The water evaporates through the leaves.

Water absorption and evaporation are approximately the same. Only a small percentage of it synthesizes substances.

How to properly water fruit trees and shrubs, depending on the root system

The vital activity of plants directly depends on watering. Young plants especially need watering, which need to be watered once a week, except on rainy days. Water deficiency can be detrimental to appearance and plant health. They may eventually die.

When planting, it is necessary to take into account how close the groundwater is located in the ground - a shallow occurrence will destroy the roots, they can rot.

There are three types of irrigation - sprinkler irrigation, root irrigation and soil irrigation. When choosing watering, many factors need to be considered - climatic conditions, weather, plant features, soil.

Plants with a rod system can extract water deep underground. The fibrous one does not have such an opportunity. In addition, garden plants such as carrots and beets have a rod system and a powerful root that stores food and moisture in case of drought.

In such plants, the root, which develops as an extension of the stem, is called the main one, the lateral ones branch off from it. The top of the root together with the lower thickened part of the stem forms a caudex - one-headed, if the stem is one, or many, if there are several. Renewal buds are laid on the caudex. The core root system is well-known aquilegia, seaside armeria, gypsophila paniculata, mullein, lupine, poppies, spurge, many umbrella (including feverweed), lumbago, ash... The taproot can be thick (fusiform), like acanthus, broad-leaved bells, nettle-leaved, milk-flowered, codonopsis, reviving moon, mallow, baptisia.

Pin-root plants do not like transplants - it is better to plant them immediately in a permanent place. In the flower garden, they steadily occupy the niche allotted to them, which is why they are valuable. If a transplant is still required, you can cut the main root at a depth with a shovel in the spring, then by autumn the root system will become more branched and compact, and the transplant will be more successful.

How do tap root plants reproduce?

Taproot plants are more often propagated by seeds. Seedlings and young plants can bulge in spring on clay soils, and after the snow melts, they need to be buried. However, if the plant does not set seeds or is varietal, root and green cuttings or root division can be used.

What are suckers?

Some taproot plants are capable of spontaneously budding on shallow, horizontally growing roots. An example can be cited anemone (forest, Japanese and its hybrids), bells (rapunzel, speckled and its hybrids, Takeshima), thermopsis, horseradish... They form a constantly growing clump above the root zone and are most often aggressive, like many rhizome plants, care and reproduction are the same. Autumn anemones, who do not like transplanting, divide in the spring, cutting through the ground between the stems with a knife or a shovel. A year later, the cuttings are planted in the spring.

Plant propagation by green cuttings

With green cuttings(using green stems and leaves) it is useful to use rooters, such as "Kornevin". It is better to root such cuttings in a greenhouse, arranged in a shaded, cool place. With small amounts of material, plantings can be covered plastic bottle... The plantings are regularly sprayed and aired. After rooting (from 1 to 1.5 months), the greenhouse is opened. For the winter, plants are covered with spruce branches or leaves. Seated in the spring.

Stem cuttings can be multiplied aquilegia, swing, lupine, oriental poppy, peony... They take them during active growth, that is, from some ( lupine, poppy) during the entire growing season, in others ( aquilegia, peony) - before flowering. Usually use the upper part of the shoot, which is cut into pieces of 2-3 internodes. In some cases, they tear off (do not cut off) side rosettes or small shoots with a heel - a piece of caudex. Cuttings are planted with a slope in holes made with a stick with a depth of 1-1.5 cm.

Cut with leaves incarvillea(July), lupine(July), fraxinella(June). Select well-formed leaves and pull them off the stem, which is called "heel". They are planted with a slope to a depth of 1-1.5 cm. The rooting period is from 1 month in Incarvillea to 2.5 months in an ash tree.

Workshop on plant propagation by root cuttings

Plants that can form buds on the roots are cuttings: acanthus, varietal mullein, oriental poppy and its varieties, erythematosus, kermek, lumbago. A more successful result can be obtained by planting cuttings in pots with loose, light, as for crops, soil. It is necessary to maintain constant soil moisture, but without stagnant water. Stimulants are not used.

The timing of cuttings is individual. For example, oriental poppy is cut after foliage dies before frost. Cuttings are cut up to 5 cm long. Rooting occurs in 1-2 months. Mullein is cut until early June.

Step 1. Dig up the mother bush of the oriental poppy and cut off one or two large roots with a knife. Cut them into pieces 5-8 cm long, making the bottom cuts oblique.

Step 2. Stick the root cuttings strictly vertically flush with the soil, top up, sprinkle with a layer of soil or coarse sand about 1.5 cm and water.

Step 3. Cover pots with cuttings with foil or glass and place in the shade. After the leaves appear, remove the film.

Workshop on plant propagation by dividing roots

Divide thick roots with formed caudex and renewal buds (aquilegia, umbelliferae, lupine, spurge, ash tree). Do this before the start of active growth, in the spring. True, this method is rarely used - it is rather unreliable.

Step 1. Dig up the mother root, cut the main root longitudinally, so that on each half there is a piece of stem with two or three buds.

Step 2. Dry the cut and sprinkle with ash.

Step 3. Plant the cut in a pot or permanent place.

The roots of a plant are its vegetative organs, which 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

The common thing in different root systems is that the root is always divided into main, lateral and adventitious. 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 downward.

The lateral roots extend from it and are called second-order roots. They can branch, and from them the adventitious roots, called roots of the third order, branch off. 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 - pivotal and fibrous. And our main question concerns how the core and fibrous root systems differ.

The core root system is characterized by the presence of a pronounced main root, while the fibrous root system is formed from the adventitious and lateral roots, and its main root is not pronounced and does not stand out from the general 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, carrots, maple, birch, currants, and watermelon have a core root system. Wheat, oats, barley, onions and garlic, lilies, gladiolus and others have a pelvic root system.

Modified shoots underground

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

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

Stolons are underground shoots, at the end of which bulbs, tubers and rosette shoots are formed.

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

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