The embryonic shoot and its modifications in a state of relative dormancy are called buds.

Bud- organ of growth, renewal and vegetative propagation(Encyclopedia of Horticulture, 1990). Kidneys fruit plants differ from each other in structure and function, location on the stem and time of germination.

According to the structure and functions of the kidneys there are vegetative And generative.

Vegetative (growth) bud is a shortened shoot consisting of an axis, a cone, the growth of leaf primordia and covering bud scales. Vegetative buds are smaller, more elongated and pointed than generative ones. After germination, vegetative buds produce shoots of varying lengths.

Generative (flowering, fruiting) buds contain the rudiments of flowers, and in a number of breeds and vegetative organs- leaves and growth buds. In this regard, in their structure, generative buds are simple and mixed (vegetative-generative).

Simple generative buds have well-developed flower primordia, from which only flowers and fruits develop. After fruiting, only a scar remains in place of a simple flower bud. Such buds are characteristic mainly of stone fruits.

Mixed (vegetative-generative) buds have complete rudiments of flowers, inflorescences, leaves and stems. From one such bud, generative organs, as well as leaves and shoots, are formed. They are characteristic of pome-bearing species. Generative mixed buds are larger and rounded compared to vegetative ones.

Knowing features generative buds, you can predict the next year’s harvest and correctly regulate the crop load of trees when pruning.

Depending on their position on the stem, the buds are apical (terminal, terminal) and lateral (stem, collateral).

Most often, the buds are located at the top of the stem and in the axils of the leaves, singly, sometimes in pairs or three. If several buds form in the leaf axil, they are called serial if they are located one under the other (walnut), and collateral if they are located side by side (peach).

From total number As a rule, only a few axillary buds formed on the plant subsequently develop. One part of the axillary buds dies completely, and the other indefinitely for a long time freezes, turning into so-called dormant buds, which begin to grow if the main bud dies.

The buds formed on the stems of different breeds and varieties germinate into different times. Depending on the time of germination, the buds are divided into early ripening, normal(late ripening) and sleeping.

Early ripening buds under normal conditions, they germinate in the year of formation and, as a rule, produce premature shoots.

Normal (late-ripening) buds under normal conditions they germinate and produce new growths the next year after formation.

Dormant buds underdeveloped and outwardly remain long time inactive (apple trees are up to 20-25 years old). Their axis lengthens annually as the branches thicken. As a result, the bud maintains a superficial position on the stem. In pome-bearing species, dormant buds are more durable (they live up to ten years), while in stone fruit species they are less durable, especially in cherries. They can begin to grow if the apical bud is removed, or if it dies on its own. Of particular note are the dormant buds in the trunks fruit trees, immersed in wood, overgrown with it and growing from the cambium as the trunk thickens. After breaking or cutting the trunk above them, they “wake up”, forming shoots.

1. What structure does the seed embryo have?

In the embryo, there are germinal roots, stalks, buds and cotyledons.

2. What kind of fabric is called educational?

Educational tissue consists of small, tightly adjacent living cells that constantly divide.

Laboratory work. The structure of the kidneys. Location of buds on the stem

1. Consider the shoots different plants. Determine how the buds are located on the stem and sketch them.

2. Separate the buds from the shoot and examine them external structure. What adaptations help the kidneys withstand adverse conditions?

From exposure unfavorable conditions external environment The buds are protected from the outside by dense, leathery bud scales.

3. Cut the vegetative bud lengthwise and examine it under a magnifying glass. Using Figure 19, locate the scales, rudimentary stem, rudimentary leaves and growth cone. Draw a cross-section of a vegetative bud and label the names of its parts.

4. Study the generative bud. What do vegetative and floral buds have in common and how do they differ? Use Figure 19 for comparison.

General: the outside of the buds is covered with dense, leathery bud scales that protect them from exposure to adverse environmental conditions. Through a magnifying glass, on a longitudinal section of the bud, the rudimentary stem is clearly visible, at the top of which there is a growth cone. Very small rudimentary leaves are located on the bud stem. In the axils of these leaves there are rudimentary buds.

Differences: Inside some buds on the rudimentary stem there are only rudimentary leaves. Such buds are called vegetative or leaf buds. Generative, or floral, buds are rudimentary buds or inflorescences,

5. Compare the structure of the bud and shoot. Draw a conclusion.

The stem with leaves and buds located on it is called a shoot. The bud also has a stem on which very small rudimentary leaves are located. In the axils of these leaves there are rudimentary buds. Thus, the bud is a rudimentary, not yet developed shoot.

Questions

1. What is an escape? What parts does it consist of?

A shoot is a stem with leaves and buds located on it. The stem is the axial part of the shoot, the leaves are the lateral ones. The sections of the stem on which leaves develop are called nodes, and the sections of the stem between the two closest nodes of the same shoot are called internodes.

2. What types of leaf arrangement do you know?

Plants have an alternate (spiral), opposite, whorled leaf arrangement.

3. What is a kidney?

A bud is a rudimentary shoot that has not yet developed.

4. How are kidneys distinguished?

Generative, or floral, buds are larger than vegetative ones and have a more rounded shape.

5. How can buds be located on shoots? Establish a relationship between the location of the buds on the shoot and their location.

At the top of the shoot there is usually an apical bud, and in the axils of the leaves there are axillary buds.

The arrangement of axillary buds repeats the arrangement of leaves on the stem. Poplar, cherry, birch, bird cherry, hazel have an alternate arrangement of buds. The buds are located opposite on the shoots of lilac, elderberry, jasmine, honeysuckle and indoor plants fuchsia, pilea, coleus, which are characterized by the same leaf arrangement.

6. What structure does it have? vegetative bud?

Very small rudimentary leaves are located on the bud stem. In the axils of these leaves there are rudimentary buds.

7. How do generative buds differ from vegetative ones?

Generative, or floral, buds, in contrast to vegetative ones, in addition to rudimentary leaves, on the rudimentary stem there are rudimentary buds or inflorescences.

8. How does the shoot grow in length?

The development of the shoot begins with the opening of the buds. When the bud scales fall off, intensive shoot growth begins. The shoot lengthens due to the division of cells in the growth cone (educational tissue). Young cells grow, forming new sections of the stem with leaves and buds. As you move away from the apical point of growth, the ability of cells to divide weakens and is soon completely lost. New cells turn into cells of the integumentary, main, mechanical or conductive tissue of the shoot, depending on their location.

Think

When the average daily temperature is above +5°C, plant vegetation begins, accompanied by active spring sap flow, that is, the supply of water with dissolved in it nutrients from the roots up through the vessels of the wood. At the same time, the speed of water movement is woody plants amazingly large: about 40 cm per minute. This means that in 5 minutes the water in the vessels rises to a height of two meters. The intensity of spring sap flow can be judged by the release of the well-known birch sap.

If trees are pruned before sap flow begins, the surface of the cuts is dry and the putty easily sticks to it. And when pruning, it is wet during sap flow, so the putty does not stick well. After some time, the juice will begin to gush out, rejecting the garden varnish.

"Weeping" trees are needlessly depleted. In addition, the juice flowing down the bark becomes a breeding ground for various harmful microorganisms. In particular, it settles here sooty mushroom, due to which the surface of the trunk and branches turns black. At the same time, the stomata of the bark are clogged, air exchange is disrupted, which is why the trees look oppressed, and subsequently their natural winter hardiness decreases.

Tasks

1. Place a branch of a tree or shrub in water and watch the development of shoots from the buds. Write down when the branch was placed in water, when its buds swelled, its scales opened, a shoot appeared and leaves blossomed.

2. Sprout two bean or pea seeds in a pot of soil. When the stems of the plants reach 7-10 cm in height, cut off the top of one of them. Observe what happens to the plants after one or two weeks.

3. Trim the top of a ficus or other indoor plant. Watch the shoots grow.

4. Analyze the results of your observations. Draw conclusions.

If you remove the apical bud, the shoot stops growing in length, but it develops side shoots. If you cut off the top of a side shoot, it will also stop growing in length and begin to branch.

Buds on plants are presented in 2 main varieties - vegetative and generative. What is the specificity of both of their varieties?

What is a vegetative bud?

Any bud is the germ of a shoot of a plant. As a rule, it is formed in the axil of the leaf or in the terminal part of the shoot. Sometimes buds form on stems and roots. The vegetative shoot primordium includes the rudimentary stem and leaves.

Vegetative bud

The plant bud in question can be formed from a dormant bud that forms on a tree branch. Shoots grow from appropriate primordia during various stages of the growing season - for example, in spring.

What is a generative kidney?

This type of bud is the germ of a shoot, from which flowers and inflorescences of plants then grow. In principle, cases of formation of sections of stems or leaves from generative buds are possible (their rudiments are also present in the structure of the corresponding bud of some plants).

Comparison

The main difference between a vegetative bud and a generative one is that stems and leaves of plants grow from the bud of the first type, and flowers or inflorescences grow from the bud of the second type.

It should be noted that there are also mixed, that is, vegetative-generative buds. As we mentioned above, in the structure of the generative buds of some plants there are also rudiments of stems and leaves.

Generative buds are usually larger than vegetative ones. Their apex is in many cases more rounded than that of vegetative rudiments.

Having determined what the difference is between vegetative and generative bud, we reflect the conclusions in the table.

general characteristics shoots and buds

The shoot consists of the axis of the stem and the leaves and buds extending from it. In a more specific sense, a shoot can be called an annual unbranched stem with leaves and buds, developed from a bud or seed. The shoot develops from the embryonic bud or axillary bud and is one of the main organs higher plants. Thus, the bud is a rudimentary shoot. The function of the shoot is to provide air nutrition to the plant. A modified shoot - in the form of a flower or spore-bearing shoot - performs the function of reproduction.

The main organs of the shoot are the stem and leaves, which are formed from the meristem of the growth cone and have a single conducting system (Fig. 3.11). The portion of the stem from which a leaf (or leaves) arises is called knot, and the distance between nodes is internode. Depending on the length of the internode, each repeated node with an internode is called metamer. As a rule, there are many metamers along the shoot axis, i.e. the escape consists of a series of metamers. Depending on the length of the internodes, the shoots are elongated (in most woody plants) and shortened (for example, the fruits of an apple tree). Such herbaceous plants, like dandelion, strawberry, plantain, tamed shoots are presented in the form of a basal rosette.

Stem called a plant organ that represents the axis of the shoot and bears leaves, buds and flowers.

Main functions of the stem. The stem performs supporting, conducting and storage functions; in addition, it is an organ of vegetative propagation. The stem provides a connection between roots and leaves. In some plants, only the stem performs the function of photosynthesis (horsetail, cactus). The main external feature that distinguishes a shoot from a root is the presence of leaves.

Sheet is a flat lateral organ extending from the stem and having limited growth. The main functions of the leaf: photosynthesis, gas exchange, transpiration. The leaf axil is the angle between the leaf and the overlying part of the stem.

Bud- this is a rudimentary, not yet developed shoot. The classification of kidneys includes various features: By vegetative-generative (6b); 7 - bird cherry; tip of growing shoot composition And functions buds are vegetative, vegetative-generative and generative.

Vegetative the bud consists of a growth cone of the stem, leaf primordia, bud primordia and bud scales.

IN vegetative-generative a number of metameres are laid in the buds, and the growth cone is transformed into a rudimentary flower or inflorescence.

Generative, or floral, the buds contain only the rudiment of an inflorescence (cherry) or a single flower.

Rice. 3.11. The main parts of the shoot: A - shortened shoot of the eastern plane tree: 1 - internode; 2 - annual growth; B - extended shoot

Rice. 3.12. Different types of closed buds: 1 - vegetative bud (oak); 2 - vegetative-generative bud (elderberry); 3 - generative bud (cherry)

By the presence of protective scales buds are either closed (Fig. 3.12) or open (Fig. 3.13). Closed the buds have covering scales that protect them from drying out and temperature fluctuations (in most plants of our latitudes). Closed buds can go into a dormant state during the winter, which is why they are also called wintering. Open buds are bare, without protective scales. Their growth cone is protected by the primordia of the middle leaves (in buckthorn; tree species of the tropics and subtropics; aquatic flowering plants). The buds from which shoots grow in the spring are called buds renewal.

By location on the stem there are buds apical And lateral. Due to the apical bud, the main shoot grows; due to the lateral buds - its branching. If the apical bud dies, the lateral bud begins to grow. The generative apical bud, after the development of the apical flower or inflorescence, is no longer capable of apical growth.

Rice. 3.13. Structure of open buds: 1 - wintering buds of viburnum-pride; 2 - birch; the tip of a growing shoot (2a) and its apical bud (2b); 3 - nasturtium bud; 4 - clover bud; general form(4a) and diagram internal structure(4b); 5 - grass shoot; 6 - diagram of a longitudinal section of its apical bud; vegetative (6a) and

Axillary buds are laid in the axils of the leaves and produce lateral shoots of the following order. The axillary buds have the same structure as the apical ones. The growth cone is represented by a primary meristem, protected by rudimentary leaves, in the axils of which there are axillary buds. Many axillary buds are dormant, which is why they are also called sleeping(or eyes). Adventitious buds usually develop on the roots. In woody and shrub plants from them a root shoot emerges.

Deployment of an escape from a bud. The first shoot of a plant is formed when a seed germinates from an embryonic shoot. This is the main shoot, or 1st order shoot. All subsequent metamers of the main shoot are formed from the embryonic bud. From the lateral axillary buds of the main shoot, lateral shoots of the 2nd and later 3rd order are formed. This is how a system of shoots is formed (main and side shoots of the 2nd and subsequent orders).

The transformation of a bud into a shoot begins with the opening of the bud, the appearance of leaves and the growth of internodes. The bud scales quickly dry out and fall off when the bud begins to expand. They often leave scars at the base of the shoot - the so-called bud ring, which is clearly visible in many trees and shrubs. By the number of bud rings, the age of the branch can be calculated. Shoots growing from buds in one growing season are called annual shoots, or annual growth.

IN shoot growth in length and thickness a number of meristems are involved. Growth in length occurs due to the apical and intercalary meristems, and in thickness - due to the lateral meristems (cambium and phellogen). On initial stages development, the primary anatomical structure of the stem is formed, monocots lasting throughout their life. In dicotyledons and gymnosperms As a result of the activity of secondary educational tissues, the secondary structure of the stem is formed quite quickly from the primary structure.

Leaf arrangement- the order of placement of leaves on the shoot axis (Fig. 3.14). There are several leaf arrangement options:

1) alternate, or spiral - one leaf extends from each node of the stem (birch, oak, apple, pea);

Rice. 3.14. Leaf arrangement: A - alternate (common peach); B - opposite (ovate-leaved privet); B - whorled (oleander)

2) opposite - at each node two leaves are attached opposite each other (maple);

3) cross-opposite - a type of opposite, when the oppositely located leaves of one node are in a mutually perpendicular plane of another node (lamiaceae, carnation);

4) whorled - 3 or more leaves extend from each node ( raven eye, anemone).

Rice. 3.15. Types of shoot branching: apical dichotomous: A - diagram; B - algae (dictyota); lateral monopodial: B - diagram; G - pine branch; lateral sympodial type monochasia: D - diagram; E - bird cherry branch; lateral sympodial dichazia type: F - diagram; Z - lilac branch; 1-4 - axes of the first and subsequent orders

Branching pattern of the shoot(Fig. 3.15). Branching of shoots in plants is necessary to increase the area of ​​contact with the environment - water, air, soil. There are monopodial, sympodial, false dichotomous and dichotomous branching of the shoot.

1. Monopodial- shoot growth is maintained for a long time due to the apical meristem (in spruce).

2. Sympodial- every year the apical bud dies, and shoot growth continues at the expense of the nearest lateral bud (in birch).

3. False dichotomous(with opposite leaf arrangement, sympodial variant) - the apical bud dies, and growth occurs due to the 2 nearest lateral buds located below the apex (in maple).

4. Dichotomous- the cone of growth of the apical bud (apex) is divided into two (moss club, marchantia, etc.).

According to the nature of the location of the shoot in space, they are distinguished:erect the escape; rising a shoot that develops horizontally in the hypocotyl part and subsequently grows upward as an erect shoot; creeping shoot - grows in a horizontal direction, parallel to the surface of the earth. If a creeping stem has axillary buds that take root, the shoot is called creeping(or mustache). In creeping shoots, nodes form adventitious roots(Tradescantia) or mustache-stolons, ending with a basal rosette and giving rise to daughter plants(strawberries). Curly the shoot wraps around additional support, since its mechanical tissues are poorly developed (convolvulus); clinging the stem grows, like a climbing one, around an additional support, but with the help of special devices - tendrils, a modified part of a complex leaf.

Answer from Alina Nosova[newbie]
1) vegeto - I revive, excite,
vegetativus - growing,

Answer from Suck through[guru]
They differ from each other in that (if you don’t delve into microbiology) that vegetative buds produce only leaves, while generative buds, in addition to leaves, also have flowers, thanks to which the tree bears fruit. The buds are formed even before the leaves fall in the leaf axil. Therefore, it is possible to judge whether there will be a harvest for next year this year. External signs they differ in that the vegetative bud is cone-shaped and slightly elongated, while the generative bud does not have a sharp cone at the apex, it is smoother and rounded. Best time to determine the future harvest, this is the spring of next year, when the average daily temperature is about +5 degrees. The process of bud swelling is underway. It becomes larger and then you can clearly see everything that I talked about earlier.
P.S. when pruning in spring, do not be afraid to cut out branches with generative buds, this will not harm the tree and will not reduce the yield (if pruned correctly)

Answer from Neurologist[newbie]
Vegetative bud: Formed in the axil or at the tip of the shoot. It may immediately begin to develop, or it may dry out. A bud is a shortened shoot; when a bud germinates, it produces shoots of varying lengths.
Generative bud: The buds contain the primordia of flowers. They are more rounded and dense. From the generative bud, only a portion of the stem and leaves develop.

Answer from Lumbago[newbie]
vegetarian

Answer from Just Do it[newbie]
Well, in general, vegetative - only with a rudimentary shoot, and generative - with a rudimentary shoot and flower primordia