How the variety is bred

The science that develops methods (methods) of breeding plant varieties is called a selection. The Latin word "selection" in Russian means selection or choice.
Human selection has been used for a long time. primitive people selected wild plants that gave them food or fiber for clothing, and carried them to their dwellings. As a result of long-term selection, new, cultivated plants appeared. It can be said that all the cultivated plants that we cultivate in our fields, vegetable gardens, orchards are mainly the result of centuries of human activity.
Many types and forms of plants, created by unknown breeders, have existed since time immemorial. About two thousand years ago, in ancient Rome, the works of the writer and agronomist Columella, the scientist Varro, the poet Virgil appeared, in which the first instructions are found on how to select plants. By the end of XVIII - early XIX in. Breeders-practitioners brought out many varieties and forms of plants that had never been seen before, especially vegetable and ornamental flowers. They also achieved great success in breeding new breeds of farm animals. So, England at that time became the leading country in the development of breeding livestock, the world supplier of breeding horses, cattle, chickens. In France, Germany, the United States, large enterprises also developed, supplying Agriculture specially bred high-grade seeds and high-bred animals.
Since the first half of the last century, a particularly rapid development of natural science began. Scientific discoveries followed one after another. The creation of the cell theory was of paramount importance. Many regularities in the reproduction and nutrition of plants have been established.
With the development of natural science, scientific selection appeared, which was based on the theory of Charles Darwin.
Let's get acquainted with the methods that breeders use in their work to develop new varieties or forms of plants.
The selection method, although it is the most ancient, still remains one of the main ones in plant breeding.
In every crop there are better and worse plants, and among the best there are the best. For example, for cereals, these are plants with a large and multi-grain ear, resistant to diseases, shedding, and lodging. The best ear is threshed and each grain is sown separately. Among the grown plants, we will again find the best and the worst. Again, we will select the best of them. Such repeated selection can result in a more or less homogeneous material that will have all the features and properties that interest us. The selection must be carried out in the same soil and climatic conditions in which new variety will be cultivated.
You have to be very observant, be able to notice structural features, properties and characteristics of plants that distinguish them from all the others. For this, careful monitoring of the plants grown is necessary. After making sure that the plants have become homogeneous in terms of traits and properties that are valuable to us, we can proceed to their simple reproduction ...
But sometimes selected plants lose their traits in the next generation. The reasons for this phenomenon are different.
For example, under the influence different conditions non-hereditary changes, so-called modifications, can occur in the plant. Many forms of soft wheat grown in the valley have a white or slightly reddish ear, and in the highlands the color of the ear becomes dark red or almost black. But the seeds sown in the valley will again give bright ears.
Another example. All flowering plants mainly divided into cross-pollinated and self-pollinated. But there are plants that, by the nature of fertilization, are both at the same time. If the conditions are favorable, i.e., the weather is sunny, warm, they bloom openly and cross-pollination occurs. In inclement weather, the flower does not fully open, which leads to self-pollination. It is much more difficult to conduct selection among "cross-breeders" than among self-pollinating plants. So, for example, in winter rye one can often observe

the appearance of ears with grains of intense pink, almost crimson color. However, the selection of plants for this trait is usually not successful. Due to cross-pollination, plants grow from raspberry grains, in the ears of which grains are formed with the usual color for winter rye.
In winter rye one can observe, although not often, plants with a branched ear. In order to fix this trait, we must first of all exclude the possibility of cross-pollination of this plant with any other plant that has the usual spike structure. To do this, all the ears of the selected branching type plant must be isolated together, under one paper bag. Then pollination will occur only between them. Plants with a branching structure of the ear, developed from the obtained seeds, must be grown separately, removing all plants with non-branching ears. In order to fix this trait, it is necessary, in subsequent generations, immediately after earing, to destroy all plants in which ears are ordinary, unbranched. Then natural cross-pollination will occur between plants that have only a branched spike structure. In this way, we have created a new form of winter branched rye.
In some cases, non-hereditary changes are quite dramatic. In this way, for example, the famous American breeder JI. Burbank developed a new potato variety. Here's how it happened. In a potato field, where a little-known variety of potatoes grew, which usually did not produce seeds, Burbank discovered a berry on one plant. It contained 23 seeds, which he sowed in the garden in the spring. Lush bushes developed from each seed, but in autumn none of these plants produced berries, but each of them formed a nest of beautiful tubers. Burbank wrote about this: "As we moved along the row, digging one bush after another, we found tubers of a new type on each subsequent bush. One had small tubers of an unusual shape, the other large ones with deep eyes, the next - tubers are red, with a rough skin ... But on two bushes there were tubers that could be immediately distinguished into an independent variety. They were very large smooth white tubers, superior in every respect to any of the existing varieties. "
The Burbank potato variety, although it was introduced in 1872, is cultivated in the fields to this day. Burbank called his valuable find a discovery. In his words, "materials for discoveries surround us in abundance." This is very true. A careful observer can find a lot of value in the forest, in the meadows, on the slopes of the mountains, on the shores of the seas, rivers and in any field.
Selection is the simplest method of obtaining new varieties of plants, it is the most accessible to nature lovers. But, as you can see, it has its own difficulties.
In breeding, the method of hybridization (crossing) is also used.
Before proceeding to crossbreeding, they set a certain task. For example, it is necessary to obtain a variety of wheat that would be more productive. To achieve this goal, first of all, the source material is selected. What should it be? Along with other positive properties and characteristics, selected varieties of wheat should be distinguished by high yields.
Seeds of selected varieties are sown on the site (breeders call it the nursery of the source material) under normal, field conditions. From the grown plants, the best ones are selected in terms of a combination of economically useful traits, as well as in terms of productivity, and they are crossed with each other. The resulting seeds are then sown in a hybrid nursery with well-cultivated and fertilized soil, where the best plants are again selected. The seeds of the best hybrid plants of different generations are then sown in a breeding nursery, where the progeny of the previously bred plant, which is called the line, is evaluated. The best lines go to the control nurseries for further study and then to the preliminary variety testing of hybrids. The best varieties that have passed the test enter the station competitive variety testing. Here, high-class varieties are usually selected, which are sent to the state variety testing system. If the variety survives the competition in this test, i.e., in certain areas, regions of the country, it takes first place in terms of yield and other economically valuable traits, it is recommended for cultivation there and from that moment becomes a zoned variety, i.e. a state variety.
Most modern varieties are obtained by crossing closely related forms (within the species). However, in our time, the so-called distant hybridization of plants related not only to different types but also childbirth. Scientific Foundations distant hybridization were laid by I. V. Michurin.
So, by the method of distant hybridization, I. V. Michurin created, for example, a wonderful cherry variety Krasa Severa. He pollinated the flowers of the early Vladimirskaya cherry with the pollen of the Winkler white cherry variety (cherries and cherries belong to different botanical species). Cherries are hardier than sweet cherries, but sweet cherries are larger and contain more sugar. The resulting hybrid plants gave large fruits, while the new variety proved to be resistant to frost and disease.
In our time, the method of distant hybridization is widely used in the selection of all crops, including grain plants, in particular wheat, rye, and barley.
With distant hybridization, backcrosses are sometimes used to obtain subsequent generations - hybrids of the first generation are crossed with one of the parental forms.
Many breeders use in their work the method of complex stepwise hybridization, which is based on a system of repeated crossings. The author of this method is the scientist-breeder A.P. Shekhurdin.
Valuable varieties of wheat - Albidum 43, Albidum 210, Albidum 24, Steklovidnaya 1, etc. were obtained by the method of complex stepwise hybridization.
Great success can be expected from crossing cultivated plants with wild ones. Let us give an example from our practice of obtaining wheat-couch grass hybrids. Ordinary wheat has a number of disadvantages: it is not resistant to adverse conditions, it suffers from frost and drought, it is affected by diseases, its grain is mealy.

Wheatgrass is not afraid of either drought or cold, some of its species are very resistant to fungal diseases. The grain of wheatgrass contains a lot of gluten, valuable for baking. Is it possible, by crossing these two plants, to obtain hybrids that would combine the beneficial features of both wheat and wheatgrass?
cultivated plants interbreed with wild in most cases with difficulty. Often hybrids of the first generation): are sterile, that is, unable to tie grains either from natural pollination or from artificial application of pollen to the stigmas. In such cases, one has to resort to different ways overcome sterility.
One of the best modern methods in these cases is the polyploidy method. It is as follows. The sprout of the hybrid seed of the first generation is treated with a solution of the poisonous substance colchicine, which, acting on dividing cells, delays the divergence of chromosomes in them and the formation of a cell septa between daughter cells. The result is cells with a double set of chromosomes. They give rise to polyploid shoots or a polyploid plant as a whole. Such polyploid plants are already capable of producing
seeds. Further, the usual selection work is carried out with them.
The combination of traits of crossed plants does not occur mechanically. This is a complex biological phenomenon that modern science studying hard. With distant hybridization, a restructuring of the whole organism occurs, often such signs and properties appear that the parents were, as it were, in a latent state. Scientists still have a lot of work to do to understand these complex life phenomena. As a result of complex and lengthy work, wheat-couch grass hybrids of the type of ordinary winter and spring wheat were created. These varieties are successfully cultivated in many parts of the country.
With the help of distant hybridization, it is possible to create not only new types and forms of plants, but also new crops, for example, perennial wheat, which can produce a crop of 2-3 consecutive years from one sowing. After harvesting for grain, it grows back, and in late autumn it is either fed to livestock in the form of green fodder or harvested for hay. These new plants, not found either in nature or among those cultivated by man, have already been created and are being improved.
Living nature, in particular the plant world, is constantly changing. This is one of the great laws of life. Using this law, a person can not only improve existing plants, but also create new ones, such as never existed on earth.
Breeding, like any science, is enriched from year to year with new methods of breeding varieties. The rapid development of physics and chemistry has put at the service of the breeder the latest technical devices, artificial climate stations, new designs of greenhouses, where you can not only grow plants from various countries of the world, but also set up experiments, breed new varieties and create species, varieties and forms.
In breeding, radiation, radioactive and chemical substances are increasingly used, with the help of which plants can be changed.
However, the most fruitful results can be expected only when all these methods are used in close combination with the main breeding methods - selection and hybridization. It is this unity of breeding methods that is the key with which a person will discover new secrets of plants and make them even more useful.

N.V. tsitsin

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"I love roses very much and dream of breeding my own variety. Unfortunately, I am a beginner grower, I have no selection experience. Could you please tell me how to breed a new variety?"

There are several ways to get a new variety. The most accessible and most common is artificial cross-pollination (pollen from the stamens of one or more varieties is transferred to the pistils of another). In this way, the largest number of modern varieties has been bred.

The breeder always sets himself a specific goal: to create a new variety with the desired characteristics - color, aroma, doubleness, flower shape. Accordingly, by selecting parental pairs according to the shape of the flower, color, smell, one can to some extent control the creation of a new rose.

Not all traits are equally passed on to offspring. Red color tends to be inherited more persistently than yellow or white. Sometimes the desired color, doubleness or flower shape is not obtained in the first combination, then it is worth repeating the same crossing the next year.

Hybridization begins with the collection of pollen. It is collected and stored for a certain time, since the anthers of roses ripen before the pistils.

This operation is started when the buds are ready to open, but have not yet opened. In clear sunny weather, in the first half of the day, the anthers are plucked with tweezers and collected in a glass container, labeled, noting the rose variety and the date of pollen collection. Then the anthers are scattered on paper in a thin layer and dried at room temperature.

You can do it differently: cut the buds, remove the petals from them and leave them in this form until the pollen ripens. When shaking the anther, it easily spills onto the paper. Then it is collected in a test tube and stored until pollination. It is best to store pollen in the refrigerator at 2-5°C.

The hybridization process also includes castration of the flower. To avoid self-pollination, anthers are removed from the flowers (while they have not yet opened). There are several ways of castration: removal of anthers; removal of anthers with stamens; removal of anthers with stamens and petals.

Castration is started a few days before the flowers bloom. Premature castration with the removal of petals in a state of dense bud, when the anthers are not quite yellow, adversely affects the life of the flower. It is carried out when the buds become loose. No more than two buds are castrated on a bush, the rest are cut off. Then the fruits are better tied and develop.

First, with a scalpel or a sharp knife, carefully cut the bud in a circle on the border with the sepals, and then cut it to the top. Then the cut part of the bud is separated, the petals are carefully bent and the anthers are plucked with tweezers. This must be done very carefully so as not to damage the pistils, as this can lead to the death of the flower.

After castration, in order to avoid unwanted pollination by insects, an insulator (parchment or gauze) is applied to the flower.

Pollination is started when a sticky liquid and a characteristic sheen appear on loose pistils. This usually happens on the 2-3rd day after castration. Before pollination, the insulator is removed from the castrated flowers, pollen is applied to the stigma with a brush or rubber band and rubbed lightly (a separate brush or rubber band is needed for pollen of each variety). Then caps are put on the flowers again. For more reliable results, pollination should be repeated the next day, especially if it rained after.

Pollination of roses is best done during the first flowering period. Data for each pollination should be recorded. This is very important for holding the hybrid into a variety. Pollination results should be checked periodically.

After 12-15 days, parchment or cellophane insulators are changed to gauze. Practice has proven that under a gauze cap, the fruits ripen and are better preserved. The fruits are harvested when they begin to turn brown. Overripe seeds (nuts) have a very dense upper cover, so they germinate for a very long time, and sometimes only after a year, which delays the selection process of a new variety.

The period of fruit development from pollination to ripening is 70 - 100 days, in some varieties of roses - more than 100 days.

After harvesting the fruits, the seeds are cleaned of pulp and stratified (mixed in boxes with sand), rubbed well in the hands, and then placed in the basement for 10-12 days, where the temperature is 5-8 ° C. After that, the seeds with sand are sown in the ground. You can sow them in boxes or pots and place them in a greenhouse.

The area where hybrid seeds are sown is well watered and mulched. If they are sown in autumn, in September, seedlings appear the next year in April-May. When the seedlings have 2-3 leaves, they swoop down.

Young plants require careful care. The first flowering is allowed only in the second half of summer. During flowering, the best promising hybrid roses for reproduction. Propagated by budding. The final selection is carried out on the 3rd-4th year, when the qualities of hybrid plants are fully manifested.

The best varieties for breeding: Gloria Dei, Cordes Sondermeldung, Crimson Glory, Geheimrat Duisberg, Spect Yellow, Frau Karl Drushki, Charlotte Armstrong.

We will tell you how to cross between two varieties of the same plant species - this method is called hybridization. Let it be plants of different colors or differing in the shape of petals, leaves. Or perhaps they will differ in terms of flowering or requirements for external conditions?

Choose plants that bloom quickly to speed up the experiment. It is also better to start with unpretentious flowers - for example, foxgloves, marigolds or delphiniums.

The course of the experiment and the diary of observations

First, formulate your goals - what do you want to get from the experiment. What are the desired traits for new varieties?

Keep a notebook-diary where you write down the goals and record the progress of the experiment from beginning to end.

Do not forget to describe in detail the original plants, and then the resulting hybrids. Here are the most important point: plant health, growth intensity, size, color, aroma, flowering time.

flower structure

In our article, a flower will be considered as an example, you can see it in the diagram and in the photographs.

The appearance of flowers in different plants can vary significantly, but basically the same.

flower pollination

1. Start by choosing two plants. One will pollinator, and the other seed plant. Choose healthy and strong plants.

2. Keep a close eye on the seed plant. Choose an unblown bud with which you will carry out all manipulations, mark it. In addition, it will have to isolate before opening- tying it in a linen light bag. As soon as the flower begins to open, cut off all the stamens from it to avoid accidental pollination.

3. Once the flower of the seed plant is fully opened, put pollen on it from a pollinator plant. Pollen can be transferred with a cotton swab, a brush, or by tearing out the stamens of the pollinating flower and bringing them directly to the seed. Apply the pollen to the stigma of the flower of the seed plant.

4.Put on the flower of the seed plant linen bag. Do not forget to make the necessary notes in the diary of observations - about the time of pollination.

5. To be safe, repeat the operation with pollination after a while - for example, after a couple of days (depending on the timing of flowering).

Obtaining hybrids

1. If pollination went well, then soon the flower will begin to fade, and the ovary will increase. Do not remove the bag from the plant until the seeds are ripe.

2. Plant the resulting seeds as seedlings. When will you receive young hybrid plants, then give them a separate place in the garden or transplant them into boxes.

3. Now wait for the hybrids to bloom. Don't forget to write down all your observations in your diary. Among the first, and even the second generation, there may be flowers that exactly repeat the parental properties without changes. Such copies are rejected immediately. Check in with your goals and select among the received new plants those that best fit the desired characteristics. You can also pollinate them by hand, or isolate them.

If you decide to seriously engage in breeding new varieties, then you will need the advice of a specialist breeder. The fact is that you will need to find out whether you really have bred a new variety or are you following the path already beaten by someone. Competition in the field of creating new varieties is very high.

For those who decide to experiment with hybridization as a home hobby, we wish to get a lot of pleasure from this activity, make many joyful discoveries and finally give all our gardening friends a new variety of some wonderful flower named after itself.

Some growers sleep and see how to breed a new variety, and what to cross to get a hybrid form that strikes the imagination in size, color and taste ... I want to disappoint those who want to try on Michurin's laurels. Selection is a long process.

If time doesn't scare you, be patient! You will need the following gentlemen's kit:

• at least five years to breed one variety;
• decent piece of land;
• the ability to endure failure;
• receive positive emotions from the lesson.

It is useful to familiarize yourself with the professional literature. This may be a textbook on viticulture by the authorship of Negrul, and "Genetics and selection of the vine" by Ayvazyan P.K. and Dokuchaeva E.N.

You also need to turn your vineyard into an impregnable fortress, otherwise the fruits of your combinations may go to banal thieves who will sell bunches on the market, and you will lose all the results of your work. Such cases are not just unsettling, they leave a bitter aftertaste for a long time.

And still it is necessary to put only feasible tasks. Entire scientific institutes are engaged in breeding frost-resistant grapes with good characteristics, and the results are still modest.

An amateur breeder cannot handle such tasks. The probability of getting a variety with frost resistance -30...-32°C from offspring with frost resistance -23 ... -25 ° С is the same as hitting the jackpot in the lottery. The same can be said about high resistance to diseases.

Despite these limitations, the field of activity of enthusiasts is very extensive. You can improve the color of the bunches, the shape of the berries, the size, the taste, the structure, the ripening time, the vigor of the growth, the yield, the sex of the flower, the seedlessness… So that's enough work.

Never cross pairs at random. Use the “duet” rule: if you plan to breed a large-berry variety with a given color of clusters, then choose both parental forms with a given color. Use this rule when setting a selection problem. The probability of getting a bisexual variety is different: when crossing bisexual varieties, the probability is 3 to 1. That is, three seedlings will be bisexual, and one will be unisexual. Previously, all same-sex forms were rejected. But if we do this now, then we would be left without Talisman, Flora, Flamingo, Victoria, Sofia, Gourmets ... So do not rush to reject hybrid forms, maybe they will have other advantages. In industrial selection, out of a hundred seedlings, only one or two with the desired properties were selected, the rest were rejected. In amateur breeding, 20-30 seedlings are considered sufficient.

And the last. It has been noted that the earlier the maturation period of the mother form, the worse the germination of hybrid seeds. The lowest germination in super-early varieties is only 1-1.5%. And in maternal forms with early term maturation - 10-25%. The best germination is in seeds from late mother bushes.

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Page 11 of 12

HOW NEW APPLE VARIETIES ARE DEVELOPED

And van Vladimirovich Michurin, the great transformer of nature, said: “We cannot expect favors from nature; to take them from her is our task.” Michurin devoted sixty years of his creative working life to the art of creating new varieties. He also pointed out the way in which new varieties of plants could be created.

This is the way of hybridization, or artificial crossing of various varieties of plants to obtain hybrids (crosses).

As is known, fruit tree without flowering it cannot bear fruit and produce seed. Only in the process of flowering, the stigma of the pistil is pollinated by pollen from the same or from another tree of the same species, and fertilization occurs. The seed that has arisen in this way will be the bearer of the characteristics characteristic of the maternal and paternal trees. And during hybridization, a person chooses producers intentionally, that is, with such properties that he would like to give to the future plant.

Here is an example from the work of I. V. Michurin. AT middle lane In the European part of the USSR, there are no pear varieties that would combine the good taste of fruits and the ability for long-term storage, that is, no winter varieties. To get a similar variety, Ivan Vladimirovich acted in this way. In 1903, several flowers of a young, six-year-old Ussuri pear tree, the first time to bloom, the small fruits of which are rough, were fertilized with pollen taken from a potted copy of the bere-royal pear, an Italian variety with tasty and long-term stored fruits.

Of the five hybrids obtained from this crossing, one, according to Ivan Vladimirovich, "successfully combined both in the properties of the tree and in the qualities of its fruits the dignity of both producing plants." The fruits ripen in late autumn and remain fresh until March (take winter Michurina).

Another example. The now widely known Slavyanka variety was obtained by Ivan Vladimirovich by crossing antonovka ordinary (mother variety) and pineapple reneta (father variety), whose birthplace is France. As a result of hybridization, the excellent taste qualities of rennet, its exceptional aromaticity were perfectly combined with the winter hardiness of Antonovka and the very significant keeping quality of its fruits (until spring).

How is plant hybridization done? It is not only useful for young gardeners, especially those working in circles, to know the technique of hybridization, but they themselves should actively take part in crossing fruit trees.

This is the technique of hybridization. On the mother plant, inflorescences are planned (the so-called groups of flowers that come out of one fruit bud) with normally developing buds and the least developed ones are removed, leaving two or three of the best. The buds, ready to bloom tomorrow, must be opened and castrated today, that is, carefully pluck out all the pollen sacs with tweezers or scissors.

In order to prevent pollen from other flowers from being brought onto the castrated flowers by wind or insects, the treated inflorescences should be enclosed in white gauze bags, carefully and carefully tied.

Pollen from the flower of the paternal variety is harvested a little earlier - one or two days before castration. Having opened a bud that is ready to bloom, but not yet bloomed, they tear off the pollen sacs with tweezers and put them in a glass jar. The collected pollen is placed for ripening in a warm and dry place, but not in the sun. Pollen soon ripens and spills out of the sacs. In this form, it can be preserved without losing viability for a month or more (this makes it possible to obtain pollen from remote areas in advance).

On the day after the castration of the flower of the mother plant, in the morning, between 8 and 12 o'clock, pollination takes place.

Pollen in a jar is shaken and then applied with a fingertip or a piece of rubber or cork, mounted on a wire, on the stigma of the pestle.

After that, the inflorescence is again enclosed in an insulator to protect the flowers, and subsequently the ovary and fruits from accidental damage. A label is attached to the branch near the inflorescence indicating the mother plant and the pollinator variety, the date and number of pollinated flowers.

Pollination of each flower must be repeated within the next three days.

In the future, as they ripen, the fruits are removed. Summer varieties are given 7-10 days for final maturation, after which seeds are selected. Varieties ripening in a long maturation are left for storage and seeds are selected from them only when the fruits begin to deteriorate.

The selected seeds are stratified in the usual manner and sown in the spring. However, it is impossible to be late with the stratification of seeds of winter varieties. It should be done in a timely manner. In this case, of course, one must be especially careful to ensure that each group of seeds has its own exact designation.

For greater success in hybridization, I. V. Michurin recommends proceeding from certain provisions established by him.

So, the best result is obtained if the producers are taken from different climatic, soil zones, from different reliefs, etc. The hybrids obtained from such crossing are easier to change in the direction we need when they find themselves in an environment unusual for them.

Young apple trees that have recently come into fruition, like adult trees, but are weakened by something (dry weather, cold spring, affected by pests), are less likely to transfer their qualities to the hybrid than plants that are in full strength of their development.

In years with a warm, moderately humid and quiet spring, there is the highest percentage of successful crosses. In such weather, the qualities and properties the best varieties, developed under favorable conditions of a warm climate, are much more fully transferred to hybrids in our area.

Especially great importance Ivan Vladimirovich attached to the influences that a hybrid plant undergoes in the first years of life. The plasticity of the young hybrid is very high, while the stability of the inherited traits is weakened by the new environment in which the hybrid plant now finds itself. Therefore, the education of a young hybrid is of great importance.

Care of trees in a hybrid nursery, tillage, pest control should be carried out at a high agrotechnical level. However, in cases where one of the producers is a southern variety, fat soil is excluded. Hybrids that grow luxuriantly in such soil are pampered. Only brought up on thin soil, hybrids are resistant to frost.

Fertilizing seedlings, says Ivan Vladimirovich, should be started only when they begin to lay their fruiting organs. Enhanced nutrition must be continued during the first three to five years of fruiting, when all the characteristic for this plant quality. In addition, it is necessary to keep seedlings of hybrids from developing a large number of small branches by pinching lateral branches in order to direct the movement of juices to the continuation shoots.