What are F1 seeds? Hybrid engine: what is it? What does hybrid mean?

IN last years A huge number of seeds of F1 hybrids of vegetables and flowers have appeared on sale. However, it is with them that the most questions are associated. Why, for example, are packets of F1 seeds much more expensive than “regular” varieties, and do they contain very few seeds (5–10 pieces)? Why are their descriptions especially tempting - “stable”, “productive”, “highly decorative”, “large-flowered”, etc.? It happens that sellers warn: “You cannot collect your own seeds from hybrids, as there will be splitting in the future.” Finally, sometimes you hear from amateur gardeners that “hybrids are probably the same as transgenic plants, they are unsafe for health.” Let's find out what hybrids actually are?

The most important feature variety is its ability to retain all its positive and negative properties in the next offspring. When receiving and storing seeds from plants of a common variety, especially self-pollinating (tomato, peas, beans) or partially self-pollinating vegetable crops(pepper, eggplant, lettuce, beans), in subsequent offspring we will get plants with almost exactly the same set of characteristics. This ability to transmit all its properties to offspring makes it easy to maintain and reproduce, even on personal plot, varieties of self-pollinating crops. But with mass procurement of seeds, when regular selection of the best plants for a given variety is not used, within 3-5 years the loss of some characteristics characteristic of a given variety is possible. As vegetable growers say, the variety is degenerating. Therefore, if you have a well-established seed production of varieties, even self-pollinating vegetable crops, once every 3-5 years you need to purchase elite seeds of the variety you like in a specialized gardening store.
It is much more difficult, but also quite possible, to propagate or maintain a variety of any cross-pollinating vegetable crop - cucumber, cabbage, zucchini, carrots, beets, pumpkin, watermelon, etc. Here the presence is nearby flowering plants growing another variety of a given crop (for example, on a personal plot) leads to cross-pollination, and consequently to a partial or complete loss of characteristics characteristic of a given variety. And the closer the two are different varieties, the stronger cross-pollination occurs. At the same time, in the offspring we receive, a mixture of characteristics of two, three or more varieties is observed, as a result the variety disappears and we have a set of plants with completely various signs and properties and low productivity. A bee or bumblebee carrying pollen flies freely from flower to flower over a distance of up to 2000 m.
Therefore, propagation of even simple cross-pollinating varieties on your own plot requires special knowledge of the biology of flowering of a particular crop. If spatial or any other isolation is observed, as well as forced self-pollination, then in the next offspring a well-selected variety will basically retain all its inherent properties. Thus, for a simple variety, it is possible to obtain and harvest seeds within several years, from which plants will grow that retain all of its main characteristics.
It reproduces completely differently hybrid variety or F1 hybrid. Even two centuries ago it was known that when crossing two different varieties in the offspring, the size of plants noticeably increases, their growth and development accelerates, early maturity and productivity increase. This phenomenon, that is, an increase in vitality in the offspring obtained from crossing two different varieties, is called heterosis. And the more contrasting the parent varieties are, the more they differ from each other, the higher the heterosis.
The practical use of the phenomenon of heterosis began in the 20-30s of the last century. Heterotic selection is carried out for all vegetable crops and F1 hybrids have been obtained, which are widely used in production. In countries with developed agriculture, ordinary varieties are practically not grown in vegetable growing. They have been widely replaced by F1 hybrids. In our protected ground, where every meter of area is accounted for, only F1 hybrids of cucumber and tomato are used.

HYBRIDS F1 AND F2.
A hybrid is the offspring obtained from crossing two genetically dissimilar parental forms: species, lines, varieties, etc. In agriculture, as a rule, first-generation hybrids are used (i.e., the first offspring from crossing parents), which denoted by the Latin letter F and the number 1. If you collect seeds from F1 hybrids and sow them, then next year second generation hybrids, or F2, will grow (this designation can be found on bags of flower seeds).

WHAT ARE THEIR ADVANTAGES? Different parents used in crossing may have some advantage (for example, one is resistant to diseases, the second is early maturing), and the resulting hybrid will have both advantages at the same time (in this case it will be both early maturing and resistant to diseases). Thus, by specially selecting parents for crossing, it is possible to obtain hybrids with a set of specified positive characteristics that the “ordinary” variety does not possess. F1 hybrids are characterized by a high level of adaptation to unfavorable factors. In early spring, at sharp changes temperature or summer heat, F1 hybrids develop significantly better than conventional varieties. High level adaptation to unfavorable factors contributes to consistently high yields.

No less important requirement requirements for F1 hybrids are their genetic resistance to diseases and pests. This is especially true when growing vegetable crops in film greenhouses. The specific microclimate of protected soil and prolonged cultivation of one or two crops in one place lead to a significant accumulation of pathogenic microflora and fauna. Chemical methods control of diseases and pests in protected soil is not always effective and reliable. In addition, tomato or cucumber fruits intended for fresh consumption should not contain residual quantities pesticides. Therefore, the genetic resistance of F1 hybrids to diseases due to the combination of characteristics of two parental lines is always higher than that of regular varieties. F1 tomato hybrids with group resistance to three to four diseases (tobacco mosaic virus, brown leaf spot, fusarium, verticillium) and root-knot nematodes have already been obtained and are being used in production.

For seeds only go to a special store.

Unlike conventional varieties with hybrid plants It is unacceptable to harvest seeds. Due to splitting, the offspring turns out to be so variegated and heterogeneous that there is no high yield out of the question. The fact that the seeds of F1 hybrids must be purchased in the store each time is their only drawback.
Get your own hybrid seeds in conditions homestead farming, without having the original parental lines, it is impossible. Therefore, if you see seeds of F1 hybrids on sale from private traders, then this is probably not true. By buying hybrid seeds on the market, you risk your harvest.
Now about the price of F1 hybrid seeds. All work on crossing two parental lines to obtain hybrid seeds is usually carried out manually in protected ground. For example, in a tomato crop, when obtaining F1 hybrids, it is necessary to castrate (that is, remove the stamens) all opening flowers on the maternal line, collect pollen from the opened flowers of the paternal line using a vibrator, and very carefully apply it several times (over two to three days) to stigma of the pistil. Work on hybrid seed production continues every day for two to three months. One person can get only 3-4 kg of hybrid tomato seeds per season. Therefore, the price of hybrid seeds is several times higher than that of conventional varietal seeds. For the buyer, the cost of seeds is only 0.5-1% of the cost of the resulting product and is justified in the harvest. However, the question arises:

Why do we need this?

Man has always strived to get a larger yield per unit area.
With the development of technologies for growing agricultural products, the requirements for varieties change. Thus, with the advent of combine harvesters, varieties with fruits that were resistant to contact with the mechanical parts of the combine were required. With the development of the processing industry, there is a demand for varieties whose fruits are ideal for various methods processing (canning, paste production, drying, freezing, etc.). With the increase in the area of protected soil, it became necessary to create special varieties for these growing conditions.
Development of economic relations and trade between different regions and countries in order to ensure year-round supply fresh vegetables and fruits contributed to the creation of varieties that tolerate transportation well and at the same time retain high commercial qualities.

As you can see, the creation of new varieties is an objective necessity for successful development traditional Agriculture and processing industry. Professional growers work only with hybrids when growing vegetables and flowers.

The biodynamic direction of agriculture does not use or recognize hybrids, declaring that their quality and nutritional value for humans are controversial issues. The use of hybrids in floriculture is completely justified: they are superior to varieties in their compactness, abundant flowering And color scheme. Whether it is necessary to grow vegetable hybrids for your own food, let everyone decide for themselves.

A hybrid car is a vehicle that is equipped not with a conventional internal combustion engine, but with a so-called hybrid power unit. The main difference between hybrid cars is that vehicles of this type are driven by using several energy sources: thermal and electrical. In other words, a hybrid car has several types of engines on board that propel the vehicle.

As for the very concept of a hybrid engine, then this term misunderstood by many as a special power plant. In fact, “hybrid” should mean several engines different types, which are combined into a complex unified system on transformation various sources energy in useful work. In the modern automotive industry, hybrid cars are equipped with two types of power units: an electric motor is paired with an internal combustion engine.

Read in this article

The main advantages and disadvantages of hybrid cars

One of the first developments was a scheme in which each of the power plants is activated under certain conditions. If the car is idle or moving at low speed, then the wheels are turned by an electric motor. To accelerate and further maintain speed, a gasoline engine is connected. Subsequent development of technology has led to the fact that on hybrids there are several options for implementing the interaction of a conventional engine and electric motor. Such interaction could be:

consistent;
parallel;
series-parallel;

Sequential interaction

The sequential circuit is reminiscent of electric cars, since the movement vehicle implemented through the operation of an electric motor. The internal combustion engine in this design is connected to a generator, from the generator power is supplied to the electric motor itself, and charging also occurs in parallel battery. On one charge lithium ion battery with the increased capacity it is often possible to travel about 50 km. path, after which the internal combustion engine is activated, which extends the specified segment up to 10 times (about 500 km.)

Parallel interaction

Hybrids with parallel interaction of installations suggest the possibility of both separate operation of the internal combustion engine and electric motor, and simultaneous operation. This design is implemented by combining an electric unit, an internal combustion engine and a transmission using special couplings. Such hybrid cars receive a low-power electric motor, which not only drives the car, but also delivers power during acceleration. Often such an electric motor is the starter and car generator, structurally occupying an intermediate position between the internal combustion engine and the gearbox.

Serial-parallel interaction

In this design, the internal combustion engine and the electric motor are connected via a planetary gearbox. A feature of this implementation scheme is that each power plant can be turned on and off, while delivering a minimum or maximum of power to the wheels. Moreover, the specified power is supplied separately or simultaneously. This circuit design contains a generator that powers the hybrid electric motor.

The leader in the hybrid car market today is Toyota Corporation, which uses a series-parallel implementation called Hybrid Synergy Drive.

Electric motor, internal combustion engine and generator are combined into common system via a planetary gearbox. The internal combustion engine produces a minimum of power at the “lower” range (Atkinson cycle), allowing you to save fuel. A hybrid car with such an interaction scheme assumes:

Economy mode of driving only on electric power with the internal combustion engine switched off, during which the electric motor is powered by the battery.
Maintaining a given speed by distributing the power of the internal combustion engine to the wheels and the generator, from which a parallel operating electric motor is powered. The battery is also recharged.
Mode of intense acceleration and heavy loads, when the internal combustion engine and electric motor operate in parallel. In this mode Electrical engine It is powered by a battery, without taking power from the generator.

Operation of hybrids: destroying myths

Hybrid cars are a new product that have not been fully improved and have many shortcomings. This is a myth, since the Toyota brand has been engaged in full-scale mass production of hybrid models for almost 20 years.
Hybrids run out of battery power, which leads to problems. This is true, but only partially. On initial stages technology development similar cases met, but today high-precision electronics do not allow deep battery discharge.
Hybrid cars break down more often and are expensive and difficult to repair. This is a myth, since hybrid cars are no less reliable in operation than conventional diesel and gasoline internal combustion engines. Most service stations comprehensively service hybrids on a par with conventional cars. Moreover, the gearbox in hybrids eliminates the presence of friction clutches, which makes such a transmission simple and reliable, which cannot be said about various types Automatic transmission. As for internal combustion engines, the engine in hybrids often operates at low speeds and does not reach peak loads. If we also take into account the Atkinson cycle, then the engine life of a hybrid engine is much greater than that of a conventional engine.
The internal combustion engine of a hybrid has less power; such cars lose dynamics compared to their analogues. Yes, the power of internal combustion engines in hybrids is less, but due to the addition of an electric motor, the total power of the units significantly exceeds the power of conventional analogues with one gasoline engine.
The consumption of a hybrid car in practice is not much different from a conventional car. This is partly true, since the consumption rate of hybrid cars directly depends on the driving modes. To achieve maximum efficiency, you need to change your driving style to slow, calm and smooth, avoiding acceleration, active throttling, etc. In other words, pressing the gas pedal hard will command the control system to start the internal combustion engine.

The idea of saving fuel in hybrid cars is to drive on electric power for as long as possible with a charged battery at speeds of up to 60 km/h, which is often enough in dense city traffic. It is also necessary to add that the system takes into account a large number of factors: outside temperature, degree of heating of the internal combustion engine and , battery charge, driving downhill or uphill, etc. IN different conditions A hybrid can use an internal combustion engine, or can move only on electric energy.

The battery for a hybrid is difficult to find on the market, and the battery takes up a lot of space in the trunk of the car. This is a myth, since batteries for hybrids are always available for order in auto stores, and are also presented wide choose on various Internet resources. In terms of free space, the battery takes up virtually no space usable space in the luggage compartment.
You cannot put gas on a hybrid car. This is a myth, since global manufacturers produce equipment compatible with a hybrid car.

Reciprocal hybrids

Reciprocal hybrids result from reciprocal crosses - hybridization that involves changing the sex of the parents associated with each genotype.

Reciprocal effects

Differences between reciprocal hybrids - reciprocal effects - indicate the unequal contribution of male and female sexes to the genotype of the offspring. If descendants from father and mother received the same genetic information, then there should be no reciprocal effects.

Measuring reciprocal effects

To measure reciprocal effects (r), you can use the expression:

where A and B are the trait values for the original crossed forms; a - the same for the hybrid ♂A x ♀B; b - for a reciprocal hybrid ♂B x ♀A. Positive value r (r > 0) will mean a “paternal” effect, negative (r< 0) - «материнский», а абсолютная величина r (│r│) даст относительную оценку этих эффектов в единицах, равных разности значения признака для исходных форм (B - A).

Reciprocal effects in birds

In chickens, the “paternal” effect was observed in the inheritance of the brooding instinct (r = 0.45, 0.38 and 0.50), sexual precocity (r = 0.59), egg production (r = 0.32, −2.8, 1.07, 0.11, 0.46, 1.14 and 2.71), and live weight (r = 0.30).

There was a “maternal effect” in egg weight (r = −1.0).

Reciprocal effects in mammals

In pigs, the “paternal” effect is observed in the number of vertebrae (selection for a long body) (r = 0.72 and 0.74), the length of the small intestine (selection for better feed costs), and growth dynamics (selection for precocity) (r = 1.8).

The "maternal effect" was observed in the average weight of the embryos, digestive system and its parts, the length of the large intestine and the weight of newborn piglets.

At the large cattle A “paternal” effect was observed for milk yield (r = 0.07, 0.39, 0.23) and milk fat production (amount of fat) (r = 1.08, 1.79, 0.34).

A “maternal effect” was observed in the percentage of fat in milk of cows (r = −0.13, −0.19, −0.05).

Theories of reciprocal effects

"The Maternal Effect"

The maternal effect may be due to cytoplasmic inheritance, homogametic constitution and uterine development in mammals. A distinction is made between the maternal effect itself, when the mother's genotype is manifested in the phenotype of the offspring. Molecules in the egg, such as mRNA, can influence early stages of the developmental process. There is also a distinction between maternal inheritance, in which the offspring receives part of the genotype exclusively from the mother, for example mitochondria and plastids containing their own genome. In maternal inheritance, the phenotype of the offspring reflects its own genotype.

"The Father Effect"

The greater influence of the father on the egg production of daughters in chickens was explained by the fact that in birds the heterogametic sex is the female, and the homogametic sex is the male. Therefore, the chicken receives its only X chromosome from its father, and if egg production is determined by it, then everything is clear. This interpretation can explain chromosomal mechanism phenomena in birds, but for mammals is no longer applicable. It is also surprising that traits that appear only in the female sex (the brooding instinct, early maturity and egg production in a hen, or milk yield and the amount of milk fat in a cow), which, it would seem, should be transmitted by the mother, are nevertheless transmitted more by the father.

Interspecific and intergeneric hybridization

Interspecific hybridization is often observed both in nature and during human cultivation (captivity) in many species of plants and animals. In nature, in areas of contact between closely related species, so-called “hybrid zones” can form, where hybrids numerically predominate over the parent forms.

Interspecific introgressive hybridization is widespread in Daphnia. In some summer Daphnia populations, hybrids predominate, which makes it difficult to determine species boundaries /

Famous experimental hybrid raffanobrassica(lat. Raphano-brassica) was obtained by G.D. Karpechenko by crossing radish with cabbage. Both species belong to different genera and have 18 chromosomes. The hybrid obtained as a result of doubling the number of chromosomes (36) was capable of reproduction, since during the process of meiosis the chromosomes of radish and cabbage were conjugated with their own kind. It possessed some characteristics of each parent and kept them pure during reproduction.

Intergeneric hybrids (both natural and those obtained by breeders) are also known in the families of cereals, Rosaceae, citrus, orchids, etc. Thus, the hexaploid genome of common wheat was formed by combining the diploid genomes of two ancestral species of wheat and one species of a closely related genus Aegilops.

Hybrids in scientific nomenclature

In botany

Hybrid plant taxa are called nototaxa.

In zoology

Sterility of hybrids

Unfavorable interactions between cytoplasmic and nuclear genes also lead to sterility of interspecific hybrids in different groups plants and animals.

Plant and animal species often differ in translocations, inversions and other rearrangements, which in the heterozygous state cause semisterility or sterility. The degree of sterility is proportional to the number of independent rearrangements: thus heterozygosity for one translocation gives 50% sterility, for two independent translocations - 75% sterility, etc. Sterility of plants is determined by the gametophyte. In heterozygotes for chromosomal rearrangements, as a result of meiosis, daughter nuclei are formed that carry deficiencies and duplications in certain areas; Such nuclei do not produce functional pollen grains and ovules. Chromosomal sterility of this type is very common in interspecific hybrids of flowering plants.

The course of meiosis in a hybrid can be disrupted either by genetic factors or differences in the structure of chromosomes. Both genetic and chromosomal sterility can be expressed in the aberrant course of meiosis. But the types of meiotic aberrations are different. Genetic sterility is common in animal hybrids, and chromosomal sterility is common in plant hybrids. Genetic analysis of some interspecific plant hybrids shows that often both chromosomal and gene sterility are observed in one hybrid.

Destruction of hybrids

In cases where a certain interspecific hybrid is sufficiently viable and capable of reproduction, generations of its descendants will contain a significant proportion of non-viable, subvital, sterile and semi-sterile individuals. These types represent unsuccessful recombination products resulting from interspecific hybridization. This suppression of vigor and fertility in hybrid offspring is called hybrid breakdown. The destruction of hybrids is the last link in the sequence of barriers that prevent interspecific gene exchange.

Hybrid breakdown is invariably found in the progeny of interspecific hybrids in plants, where it is more easily observed than in most animal crosses.

Hybrids with their own names

Hybrids in the Orchidaceae family

The selection of phalaenopsis and other beautifully flowering orchids is developing in two directions: for cutting and for potted culture.

Some artificial genera of orchids:

Brassolaeliocattleya
Rhynchosophrocattleya

Notes

Shcherbakova A.A. History of botany in Russia until the 60s of the 19th century (pre-Dravinov period). - Novosibirsk: "Science", 1979. - 368 p.
Roberts E., Card L. (1933). V World Poultry Congr., 2 , 353.
Morley F., Smith J. (1954). "Agric. Gaz. N. S. Wales" 65 , N. 1, 17.
Saeki J., Kondo K., et al. (1956). “Jpn. J. Breed." 6 , N. 1, 65.
Warren D. (1934). "Genetics" 19 600.
Dubinin N.P., Glembotsky Ya.L. (1967) Population genetics and selection. - M.: Science p. 487, 496.
Dobrynina A. Ya. (1958) Reciprocal crossings of Moscow chickens and leghorns. Tr. Institute of Genetics, USSR Academy of Sciences, M, No. 24, p. 307.
Aslanyan M. M. (1962) Peculiarities of inheritance and embryonic development of piglets when crossing Large White pigs and Swedish Landrace. Scientific report higher Schools, No. 4, p. 179.

In recent years, people have begun to think seriously about the ecology of the planet. And automakers are willingly supporting this trend by creating cars that run on environmentally friendly fuel. As for electric vehicles, they are not being seriously considered yet. The same cannot be said about hybrid cars, which are becoming increasingly popular.

What is a hybrid car. Pros and cons of a “hybrid”.

What is a hybrid car? The word hybrid comes from the Latin “hibrida”, which means cross. That is, an organism that is obtained by crossing genetically different parental forms. In our case, the parent forms are , and an electric motor. In one sentence: a hybrid car is a car powered by an “electric motor – internal combustion engine” system, which is highly efficient. Eat this unit can be either traditional fuel or electricity from batteries.

Each engine has its own specific function. For example: if the car is stopped, for example in a traffic jam, or moving slowly, the electric motor will work. When the car picks up speed, the gasoline engine comes into play.

Advantages of hybrid cars.

The main advantage of hybrid cars is that they are very economical. As a rule, their fuel consumption is 25% less than that of traditional cars. And in conditions of constantly rising gasoline prices, this point is the most important.

The next most important point is environmental friendliness. Hybrids cause less damage to our eco-system than conventional cars. This is achieved through more rational fuel consumption. Also, when the car comes to a complete stop, the gasoline engine stops working, giving the initiative to the electric motor. That is, during stops, emissions carbon dioxide practically does not occur into the atmosphere.

Unlike electric vehicle batteries, in hybrids, batteries can be recharged from a gasoline engine. Which makes its power reserve quite large. In addition, it lasts longer without refueling with gasoline.

Many people think that hybrids are much inferior in performance to traditional cars. This is wrong. All required characteristics(power, acceleration from zero to one hundred and so on), theirs is no worse.

Hybrid cars perform best in the city cycle, in which there are very frequent stops and the engine works a lot when idling. Practically, in the city it works like an electric car. If we talk about the mixed cycle, then they have no special advantages.

Toyota Prius is the most popular “hybrid” in Russia.

As already mentioned, if the car is stationary, it goes into electric motor mode. Which gives almost complete silence.

Well, the hybrid car is refueled with ordinary hydrocarbons, that is, gasoline. Everything is carried out in a standard way just like traditional cars.

Disadvantages of hybrid cars.

Nothing is perfect, and it also has its downsides. And the main one is that repairing hybrid cars is much more expensive than repairing a car with a traditional configuration. This is explained by the complexity of the engine design.

Also, due to the complexity of the design, it is difficult to find professionals who can repair the engine.

The batteries that come with hybrids can self-discharge. In addition, they cannot withstand large temperature changes and their service life is quite limited.

In addition, it is not yet known how used batteries affect environment. Therefore, their disposal is a problem.

Despite the fact that hybrid cars still have more advantages, they are not yet popular in Russia. One of the reasons for this is the price. The cost of the most popular hybrid in our country, Toyota Prius, is from 1,200,000 rubles. And this car is the cheapest hybrid. Also, they plan to release a Russian development for the mass buyer hybrid car, the so-called “Yo-Mobile”. Its price can range from 350,000 rubles. However, this project was closed.

The BMW ActiveHybrid X6 is the most powerful hybrid car available today.

In connection with the fight for the environment, buyers all over the world are encouraged to purchase hybrids. Thus, in the USA there are a number of tax incentives for owners of such cars, and even free parking spaces. Our country is also planning to introduce similar laws. In particular, reducing duties on the import of hybrid cars.

Engines running on hydrocarbons will slowly but surely lose their position. And hybrids are one of these steps. However, as long as their prices remain at the same level, there will be little demand for them.