Man in his desire to improve nature is moving further and further. Thanks to modern achievements in genetics, farmers are getting more and more unusual and interesting hybrids that can satisfy the most daring desires of consumers.
In addition, globalization leads to the spread of plant species that are not typical for a given climatic zone. We have long gone from the exotic pineapples and bananas, hybrid nectarines and miniols, etc. have become familiar.

yellow watermelon (38 kcal, vitamins A, C)

Outside, it is the usual striped watermelon, but at the same time bright yellow inside. Another feature is the very small number of bones. This watermelon is the result of crossing a wild (yellow inside, but completely tasteless) watermelon with a cultivated watermelon. The result is juicy and tender, but less sweet than red.
They are grown in Spain (round varieties) and Thailand (oval). There is a variety "Lunar" bred by the breeder Sokolov from Astrakhan. This variety has very sweet tastes with some exotic notes like mango or lemon or pumpkin.
There is also a Ukrainian hybrid based on watermelon (“kavun”) and pumpkin (“garbuza”) - “kavbuz”. It is more like a pumpkin with a watermelon flavor and is ideal for making porridges.

purple potatoes (72 kcal, vitamin C, B vitamins, potassium, iron, magnesium and zinc)

A potato with a pink, yellow or purple skin no longer surprises anyone. But scientists from Colorado State University managed to get a potato with a purple color inside. The basis of the variety was the Andean highland potatoes, and the color is due to the high content of anthocyanins. These substances are the strongest antioxidants, the properties of which are preserved even after cooking.
They called the variety "Purple Majesty", it is already actively sold in England and begins in Scotland, the climate of which is most suitable for the variety. The popularization of the variety was facilitated by the English culinary specialist Jamie Oliver. These purple potatoes with the usual taste look great in the form of mashed potatoes, an indescribable rich color, baked, and of course french fries.

romanesco cabbage (25 kcal, carotene, vitamin C, mineral salts, zinc)

The ethereal appearance of this close relative of broccoli and cauliflower perfectly illustrates the concept of "fractal". Its pale green inflorescences are cone-shaped and arranged in a spiral on a head of cabbage. This cabbage comes from Italy, it has been on the market for about 10 years, and Dutch breeders contributed to its popularization, slightly improving the vegetable known to Italian housewives since the 16th century.

Romanesco has little fiber and a lot of useful substances due to this, it is easily digested. Interestingly, when cooking this cabbage, there is no characteristic cabbage smell that children do not like so much. In addition, the exotic appearance of the space vegetable makes you want to try it. Romanesco is prepared like regular broccoli - boiled, stewed, added to pasta and salads.

Pluot (57 kcal, fiber, vitamin C)

From the crossing of such plant species as plums (plum) and apricots (apricot), two hybrids were obtained pluot, which looks more like a plum, and aprium, more like an apricot. Both hybrids named after the first syllables English titles parent species.
Outwardly, the fruits of the pluot are colored pink, green, burgundy or purple, inside - from white to rich plum. These hybrids were bred in the Dave Wilson Nursery in 1989. Now in the world there are already two varieties of aprium, eleven varieties of pluot, one nectaplama (a hybrid of nectarine and plum), one pichplama (a hybrid of peach and plum).
Plows are used for making juice, desserts, homemade preparations and wine. The taste of this fruit is much sweeter than both plums and apricots.

watermelon radish (20 kcal, folic acid, vitamin C)

Watermelon radishes live up to their name - they are bright raspberry inside and covered with a white-green skin on the outside, just like a watermelon. In shape and size, too (diameter 7-8 cm), it resembles a medium-sized radish or turnip. It tastes quite ordinary - bitter at the skin and sweetish in the middle. The truth is more solid, not as juicy and crispy as usual.
It looks wonderful in a salad, simply sliced ​​with sesame seeds or salt. It is also recommended to make mashed potatoes from it, bake, add to vegetables for frying.

Yoshta (40 kcal, anthocyanins with antioxidant properties, vitamins C, P)

Crossing such plant species as currant (johannisbeere) and gooseberry (stachelbeere) gave the joshtu berry with fruits close to black, the size of a cherry, sweet and sour, slightly astringent taste, pleasantly reminiscent of currants.
Michurin also dreamed of creating a currant the size of a gooseberry, but not prickly. He managed to bring out the gooseberry "Black Moor" dark purple. By 1939 in Berlin, Paul Lorenz was also breeding similar hybrids. In connection with the war, these works were stopped. And only in 1970 Rudolf Bauer managed to get the perfect plant. Now there are two varieties of yoshta: "Black" (brown-burgundy) and "Red" (faded red).
During the season, 7-10 kg of berries are obtained from the yoshta bush. They are used in homemade preparations, desserts, for flavoring soda. Yoshta is good for gastrointestinal diseases, for removing heavy metals and radioactive substances from the body, and improving blood circulation.

Broccolini (43 kcal, calcium, vitamins A, C, iron, fiber, folic acid)

In the cabbage family, as a result of crossing ordinary broccoli and Chinese broccoli (gailana), a new cabbage similar to asparagus on top with a head of broccoli was obtained.
Broccolini is slightly sweet, does not have a sharp cabbage spirit, with a peppery note, delicate in taste, reminiscent of asparagus and broccoli at the same time. It contains many nutrients and is low in calories.
In the USA, Brazil, Asian countries, Spain, broccolini is commonly used as a side dish. It is served fresh, drizzled with butter or lightly fried in butter.

Nashy (46 kcal, antioxidants, phosphorus, calcium, fiber)

Another result of crossing plants is neshes. They got it from an apple and a pear in Asia several centuries ago. There it is called Asian, water, sand or Japanese pear. The fruit looks like a round apple, but tastes like a juicy, crunchy pear. The color of nashi is from pale green to orange. Unlike ordinary pear, nashi is harder, so it is better stored and transported.
Neshi is quite juicy, so it is better to use it in salads or solo. It is also good as an appetizer for wine along with cheese and grapes. Now about 10 popular commercial varieties are grown in Australia, the USA, New Zealand, France, Chile and Cyprus.

Yuzu (30 kcal, vitamin C)

Yuzu (Japanese lemon) is a hybrid of mandarin and ornamental citrus (Ichang papeda). The green or yellow tangerine-sized fruit with a bumpy skin has a sour taste and a bright aroma. It has been used by the Japanese since the 7th century, when Buddhist monks brought this fruit from the mainland to the islands. Yuzu is popular in Chinese and Korean cuisine.
It has a completely unusual aroma - citrus, with floral hints and notes of pine needles. Most often used for flavoring, the zest is used as a seasoning. This seasoning is added to meat and fish dishes, miso soup, noodles. Jams, alcoholic and non-alcoholic drinks, desserts, syrups are also prepared with zest. The juice is similar to lemon juice (sour and fragrant, but milder) and is the base of ponzu sauce, also used as vinegar.
It also has a cult significance in Japan. On December 22, on the winter solstice, it is customary to take baths with these fruits, which symbolize the sun. Its aroma drives away evil forces, protects against colds. Animals are dipped in the same bath, and plants are then watered with water.

yellow beets (50 kcal, folic acid, potassium, vitamin A, fiber)

This beet differs only from the usual one only in color and in that it does not get your hands dirty when cooked. It tastes just as sweet, fragrant, good baked and even in chips. Yellow beet leaves can be used fresh in salads.

But a person is only learning to transform plant species, and nature has long been creating

It is called sexual crossing of two individuals that differ from each other by more or less signs. They may belong to two varieties, races, varieties of the same species, two species of the same genus, or different genera of the same family. In most cases, the closer the crossed individuals are to each other, the more likely it is to get viable and fertile offspring.

Sexual hybridization is of great importance and application in practical crop production. Very many of our cultivated plants, as already indicated, are sexual hybrids, partly obtained naturally in nature and taken from there into culture, partly bred by artificial crossings.

The ability for sexual hybridization in some families or individual genera and species turns out to be greater, in others less. Sometimes hybridization between morphologically closely related species fails, while it succeeds between more distant ones.

Sexual hybridization is most easily carried out between varieties and varieties belonging to the same species. Hybrids between species are obtained for the most part small in number, not very viable and infertile in the future; hybrids between genera are obtained much less frequently and in the future in most cases are sterile.

Research by I. V. Michurin showed that the sterility of hybrids in many cases is temporary.

Often, when crossing, the first generation of hybrids is characterized by extremely powerful development, exceeding the parental forms by several times in size. This phenomenon is called heterosis. In the offspring of hybrids obtained sexually, plants usually return to the previous size of their progenitors. But if such giant hybrids can reproduce vegetatively, then the resulting gigantism will also appear in vegetatively bred offspring. In this way, one can derive large varieties root and tuber crops, ornamental trees and herbaceous plants with very large flowers, etc. An annual new breeding of annual heterotic plants is also possible to increase their production, for example, in Tobacco, tomatoes, corn, etc.

In some cases of infertility of hybrids, it is possible, with the help of systematic subsequent crossings, to restore their fertility.

When crossing sexual hybrids various kinds with each other it was possible to obtain forms that are hybrids between 3, 4 or more species.

The issue of dominance - the predominance in the hybrid of certain traits of the parents or their ancestors - is the most important issue in breeding, in breeding new varieties.

I. V. Michurin believed that the hybrid does not represent something in between the producers. The heredity of a hybrid is composed only of those traits of producing plants and their ancestors, which in the early

stages of development of the hybrid are favored by external conditions. The dominance of certain traits also depends on the unequal power of producers in the sense of transmitting their traits to offspring. To a greater extent, the signs are transmitted: 1) species growing in the wild; 2) an older variety by origin; 3) an older individual plant; 4) older flowers in the crown. The mother plant, other things being equal, will transfer its properties more fully than the father plant, but if the conditions for growing hybrids are more favorable for the father plant, then its characteristics may dominate.

Plants weakened by drought or cold spring have a weaker power to transmit their hereditary properties.

To overcome the non-crossing of distant systematic species, I. V. Michurin developed a number of effective and very interesting methods from a general biological point of view.

Mediator method lies in the fact that if any two species do not interbreed with each other, then one of them is crossed with some third, with which both of these species can be crossed. The resulting hybrid - "intermediary" - has a greater ability to cross, and it can be successfully crossed with the second of those species that were planned for crossing. I. V. Michurin used this method when crossing wild almond (Amygdalus nana) with peach; the intermediary here was a hybrid obtained from crossing the wild almond with the North American David peach ( prunus davidiana). Further research has shown that such complex hybrid forms have a wide ability to interbreed with those species with which their original parental forms do not interbreed.

Method of "vegetative convergence", used by I. V. Michurin to overcome non-crossing, lies in the fact that a young seedling of one of the plants to be crossed is grafted into the crown of another, an adult plant with which it is desirable to cross. This seedling, unstable, like an unformed organism, gradually up to The flowering pores change under the influence of a more powerful rootstock, approaching it in properties and crossing with it in the future better than the original form without grafting.I. V. Michurin used this method, for example, when hybridizing apple and mountain ash with a pear.

Method of application of the pollen mixture, which also facilitates crossing, consists in mixing a small amount of the pollen of the mother (pollinated) plant with the pollen of the pollinating plant. Presumably, pollen from one's own species makes the stigma more susceptible to pollination by foreign pollen. These methods are now widely used in breeding work with a variety of plants. It is also used to mix pollen of a third type or variety, which can also stimulate pollination by pollen, without this method it does not give results.

An important role in the works of I. V. Michurin was played by the education of young hybrid seedlings with unstable heredity. Distant hybridization without further directed education often does not give the desired results. Targeted effect on hybrids is achieved various methods, including by grafting, or by the mentor method, in which the hybrid is repeatedly called to enhance certain properties. The mentor method is based on the mutual influence of rootstock and scion. It was used by I. V. Michurin in two versions. With the so-called

cuttings of a young hybrid seedling are grafted into the crown of one of its adult producers, the quality of which (for example, frost resistance) is desirable to be increased in the hybrid. The grafted hybrid, under the powerful influence of the rootstock (stand mentor), acquires to a greater extent the property desired by the hybridizer (in this example, frost resistance). Or, for example, from a seedling, a hybrid between green renklod plum and sloe, the eyes were taken and grafted: one on the renklod, the other on the sloe. In the first case, in the future, a plant with signs of renklod (Renklod thorn) was obtained, in the second case with signs of thorn (Turn sweet). The reverse effect of the scion on the stock is reflected in the so-called grafting mentor, when, for example, by grafting several cuttings of an old variety (grafting mentor), which is characterized by abundant fruiting, into the crown of a young seedling, it is possible to speed up and improve the fruiting of the stock; with other combinations of grafted plants, this method, on the contrary, succeeded in delaying the ripening of fruits, lengthening their ability to remain in bed, etc.

These new principles and methods of work, discovered by IV Michurin, are of great importance. The selection of pairs during hybridization by preliminary biological analysis of the parents, the directed cultivation of hybrids, and the acceleration of the breeding of new varieties—all this is now widely used in the breeding of new varieties of cultivated plants.

By crossing hard wheats ( Triticum durum) with soft ( Triticum vulgare) obtained some new valuable varieties of wheat. Rye-wheat hybrids have been obtained, which are of interest both by themselves and for further crosses again with wheat in order to obtain hybrids with high grain quality of wheat and cold resistance of rye. Work is underway to cross wheat with wild couch grass (N. V. Tsitsin), with perennial wild rye. By crossing potatoes with its wild relatives, varieties of potatoes were obtained that are resistant to damage by a fungus dangerous for potatoes - late blight. Work is underway on crossing annual sunflowers with perennial, sugar cane, which has a very long growing season, with its wild relatives that have a shorter growing season, cultivated watermelons with drought-resistant wild relatives, etc. Systematic management of the development of plants (and animals) and the creation of new forms of them, based on a deep study of complex biological relationships and discovering the patterns of life theoretical basis Soviet selection.

In the 30s. of the last century N.I. Vavilov noted that the problem of creating disease-resistant crop varieties can be solved in two ways: by selection in the narrow sense of the word (selection of resistant plants among existing forms) and by hybridization (crossing different plants with each other). Plant breeding methods for immunity to pathogenic organisms are not specific. They are modifications of conventional breeding methods. The main difficulties in creating immune varieties are the need to simultaneously take into account the characteristics of plants and harmful organisms that damage them. At the moment, in breeding for resistance, all generally accepted modern methods of breeding work are used: hybridization, selection, as well as polyploidy, experimental mutagenesis, biotechnology and genetic engineering.

One of the main difficulties in plant breeding for immunity is the genetic linkage of plant traits that reflect their phylogenetic history in natural ecosystems. In the process of spontaneous domestication and the formation of highly productive and high-quality forms of plants, their immune system was weakened. In those cases where selection is carried out without attention to immunity, the weakening of the latter takes place in our time.

The most important task of plant breeding, genetics, and molecular biology is to find ways to combine high productivity and other economically valuable properties of plants with signs of their immunity. It is desirable that the basis of immunity be polygenic.

The simplest solution is when it is possible to isolate plants from the population of an existing variety that are highly immune to one specific pathogen. For such a selection, one can use different methods selection and analytical methods, which take into account the heterosis of the variety population.

When drawing up breeding programs, the type of pollination of a plant population is very important (cross-pollination, self-pollination or the population belongs to an intermediate group). Selection work for immunity to a pathogen should be carried out taking into account the following factors: in the population of plants of the first group, the unit of analysis is an individual plant, the other unit is the population (variety or line).

Traditional breeding methods in creating genotypes resistant to diseases and pests

Selection. Both in nature in general and in human breeding activities, selection is the main process of obtaining new forms (the formation of species and varieties, the creation of breeds, varieties). Selection is most effective when working with self-pollinating crops, as well as plants that reproduce vegetatively (clonal selection).

In breeding for resistance, selection is effectively used both by itself (it is the main method when working with necrotrophic pathogens), and as a component of the breeding process, without which it is generally impossible to do with any breeding methods. In practical selection for resistance, two types of selection are used: mass and individual.

Mass selection is the oldest breeding method, thanks to which varieties of the so-called folk selection were created, and is still a valuable source material for modern breeders. This is a type of selection in which a large number of plants are selected from the initial population in the field that meet the requirements for the future variety, immediately evaluating a set of traits (including resistance to certain diseases). The harvest of all selected plants is combined and sown in the next year in the form of one plot. The result of mass selection is the offspring of the total mass of the best plants selected for a certain trait (s).

The main advantages of mass selection are its simplicity and the ability to quickly improve a large amount of material. The disadvantages include the fact that the material selected by mass selection cannot be checked with offspring and determine its genetic value, and therefore, it is impossible to isolate varieties or hybrids that are valuable in breeding terms from the population and use them for further work.

Individual selection (pedigree) - one of the most effective modern methods of breeding for resistance. Hybridization, artificial mutagenesis, biotechnology and genetic engineering are primarily suppliers of material for individual selection - the next stage of selection work extracts the most valuable from the provided material.

The essence of the method lies in the fact that individual resistant plants are selected from the initial population, the offspring of each of which are subsequently propagated and studied separately.

Both individual and mass selection can be one-time and reusable.

One-time selection mainly used in the selection of self-pollinating crops. One-time individual selection provides for a consistent study in all links of the selection process, selected once for a certain plant trait. One-time mass selection is more often and most effectively used to improve the variety in seed production practice. Therefore, it is also called healing.

Multiple selections are more suitable and effective in the selection of cross-pollinated crops, their effectiveness is determined primarily by the degree of heterozygosity of the source material. By repeated mass selection, resistance to necrotrophs is maintained - pathogens such as fusarium, gray and white rot, etc. Using this method, highly resistant to and were created.

Hybridization. Currently, one of the most used methods in breeding for resistance is hybridization - crossing genotypes with different hereditary abilities and obtaining hybrids that combine the properties of parental forms.

In breeding for disease resistance, hybridization is expedient and effective if at least one parental form is a carrier of hereditary factors that can provide genetic protection for the future variety or hybrid from potentially dangerous strains and races of the pathogen.

As noted earlier, such hereditary factors (effective resistance genes) were formed in the centers of related evolution of host plants and their pathogens. Many of them have already been transferred to cultivated plants from their wild relatives through distant hybridization. These are now known as crop resistance genes.

But the indisputable fact is that today most of these genes are widely used in breeding and have mostly lost their effectiveness, overcome as a result of the variability of pathogens. That's why intraspecific hybridization (between plants of the same species) in the creation of disease-resistant varieties or hybrids in some cases is unpromising. In order to obtain positive results, the breeder, involving in crossings one or another parental form, must be sure of the high efficiency of their resistance genes to the pathogen population in the place of future cultivation of the variety (hybrid).

Against this background, the increasing importance in breeding for resistance is becoming distant hybridization (between plants from different botanical taxa). After all, plants of wild and primitive species are characterized by the most pronounced immunity. The genomes of wild relatives of cultivated plants have been and remain the main natural source of resistance genes, including complex immunity. Crossing cultivated plants of existing varieties with wild species usually allows you to increase the immunogenetic properties. And if earlier the use of distant hybridization was not very popular due to the difficulties associated with the imbalance of the genomes of parental forms, the linkage of resistance with economically undesirable traits, then methods have now been developed to resolve problematic issues.

Remote hybridization makes it possible to transfer from wild plants cultural ecological plasticity, resistance to adverse factors external environment, to diseases and other valuable properties and qualities. Varieties and new forms of grain, vegetable, industrial and other crops have been created on the basis of distant hybridization. For example, the source of wheat immunity genes to, and is endemic to Transcaucasia Triticum dicoccoides Korn.

As world practice shows, a very effective type of hybridization in the selection of self-pollinating crops for resistance is backcrosses (backcrosses) when a hybrid is crossed with one of the parent forms. This method is also called the method of "repair" of varieties, since it allows you to improve a certain variety for a particular trait that it lacks (in particular, resistance to a particular disease). But it should be borne in mind that the use of this method does not allow exceeding the productivity of a variety that is “repaired” (and according to the requirements of the State Service for the Protection of Rights to Plant Varieties of Ukraine, a variety cannot be registered if it does not exceed the standard in terms of productivity).

As a rule, when backcrossing, a disease resistance donor variety is used as the mother form, and an unstable but highly productive variety (resistance recipient) is used as the parent form. As a result of their crossing, hybrids are obtained, which are re-crossed with the parent form (backcrossing). A prerequisite is that the mother forms for each next backcross are selected from resistant hybrid plants of the previous crossing, found against an infectious background. The offspring are selected according to the phenotype of the recipient variety. Backcrosses are carried out until the genotype and phenotype of the recipient is almost completely restored, while acquiring resistance to the disease characteristic of the donor.

An increase in the efficiency of plant breeding for immunity to pests can be achieved by using previously created so-called immunity synthetics (known, for example, for corn). Mentioned synthetics are created on the basis of crossing 8-10 immune lines, characterized by different ecological plasticity and composition of immunity factors. Many of the synthetics are good sources for creating immune lines for the further development of single and double interline hybrids.

Mutagenesis. Unlike hybridization methods, they are quite laborious and require many years of work to achieve the final result, experimental (artificial) mutagenesis makes it possible to increase plant variability in a short period and obtain resistance mutations that are not found in nature.

The method of experimental (artificial) mutagenesis is based on the directed action on plants of various physical and chemical mutagens (ionizing, ultraviolet, laser radiation, chemicals), as a result of which gene mutations occur in plant organisms (changes in the molecular structure of the gene), chromosomal mutations (changes in structures of chromosomes) or genomic (changes in sets of chromosomes).

The most valuable gene mutations in terms of breeding, which, unlike chromosomal ones, do not lead to sterility of pollen, infertility or inconsistency of mutant lines. Resistance gene mutations are most often associated with either a base change in a certain region of the chromosome DNA, or its loss, addition, or displacement. As a result, there is a change in the genetic code and, accordingly, a change in the physiological and biochemical mechanisms of the cell, which leads to inhibition of the growth, development and reproduction of the pathogen.

The method of artificial mutagenesis in breeding for disease resistance is used in many countries, but it cannot be considered the main method for obtaining resistant forms of plants. This method is most effectively used when working on resistance with crops that propagate vegetatively, since their propagation by seeds entails complex segregation in the offspring due to the high degree of heterozygosity.

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From time immemorial, man has been creating hybrids of both plants and animals. The most ancient in the practice of animal husbandry are hybrids of a horse with a donkey (mule, hinny) and a zebra (zebroid), a one-humped camel with a two-humped (nar), a yak and a zebu with cattle. In the pig industry, hybridization of domestic pigs with wild boar is practiced to improve adaptability to local conditions. The 20th century gave rise to a host of new hybrids: in poultry, fish farming and cattle breeding. And then there are ligers and tigers. And there is no end in sight...
Snail or plant?

Not so long ago, a message appeared in the media about the discovery of a hybrid of a plant with an animal. It was about a sea snail, whose length is three centimeters, living on the Atlantic coast of North America. A group of scientists from US and South Korean universities that discovered this miracle organism named it Elysia chlorotica. According to the New Scientist magazine, these sea snails "are a solar-powered form: they eat plants and have the ability to photosynthesize."

The hybrid found is a kind of gelatin green plant. It looks like a piece of wood and has some of its potential due to the algae genes it consumes. Not only does the snail receive chloroplasts - the intracellular organelles of a plant cell where photosynthesis takes place, which allows plants to convert sunlight into energy - it also stores them in its cells located along the intestine.

The most curious thing is that if Elysia chlorotica feeds on algae for the first time (two weeks), then for the rest of its life - on average, its duration does not exceed a year - it may not consume food. So far, scientists have not been able to reveal all the secrets of this strange creature, whose chloroplast DNA contains only 10% of the encoded protein necessary for the active life of the snail. Nevertheless, they published a number of observations and conclusions in the journals of the American Academy of Sciences.

It can't be because...

The discovery of a hybrid of a plant with an animal caused a sensation in the scientific world, but the idea of ​​crossing animals with animals of similar species dawned on mankind many years ago. A classic example of hybridization is the mule, a hybrid of a mare and a donkey.

This is a strong, hardy animal that is used in much more difficult conditions than parental forms. The mule owes this to a phenomenon called heterosis by scientists and observed both in domestic animals and in plants: during interbreeding or interspecific crosses, hybrids of the first generation experience a particularly powerful development and increase in viability.

By the way, heterosis is widely used in industrial poultry farming, for example, in breeding broiler chickens and in pig breeding. In nature, cases of crossing a wild animal with representatives of other species are extremely rare. Let's say Grant's and Thompson's gazelles coexist happily in mixed groups. These species have a lot in common, and only experts can distinguish them from each other. Despite this, cases of crossing of these two species have not been noted.

Domestic dogs can mate indiscriminately with other species, but wild canine species such as wolves, foxes, and coyotes only breed within their own species. In addition to the obvious reasons, this is also hindered by the fact that in many groups of animals and plants, powerful but sterile hybrids are formed during interspecific crossings, an illustration of which is the mentioned mule.

Since there are many examples of sterile hybrids, scientists have come to the conclusion that the exchange of genes between different populations or population systems is weakened or prevented by various barriers, and as soon as they interfere with the widespread hybridization of animals or plants of related species, they should even more interfere with the emergence of a plant hybrid. with an animal.

From numerous experiments, scientists have concluded that hybrids almost always appear in captivity as a result of unnatural living conditions or artificial insemination. Hybrids are funny ... An example of this is the majestic liger

A hybrid of a male lion and a female tiger is the largest member of the cat family. As well as the tigrolev -

a cross between a male tiger and a female lion. However, Tiger Rolls, or Tigers, on the contrary, have a tendency to dwarfism and are usually smaller in size than their parents. Male ligers and tigers are sterile. while females can sometimes bear offspring. One tiger lived from 1978 to 1998 in India, the other died at the age of 24 in 2003 at the Beijing Zoo. In the American Institute of Protected and Rare Species in Miami lives a liger named Hercules, whose height at the withers is 3 m. The first ligren appeared in our country in the Novosibirsk Zoo in 2004, and then two more ligers were born.

A leopard is the result of crossing a male leopard with a female lion. His head is like his mother's, and his body is like his father's. And there are also hybrids of hybrids - these are crossbreeds between a male tiger and a female liger / tiger lion or a male lion and a female liger / tiger lion. Such second-level hybrids are extremely rare and are mostly privately owned.

The beginning of the big cat breeding process dates back to the days when zookeepers wanted to get as many strange creatures as possible to attract the public. Hybridization has its origins in the 1800s, when zoos were roving menageries designed to make a profit, not to conserve animal species. In India, for example, interbreeding was first recorded in 1837, when a princess of the Indian state of Jamnagar presented a big cat hybrid to Queen Victoria. Despite the fact that all these giant feline hybrids invariably attract zoo visitors, many scientists believe that this way of hybridization is hopeless and even harmful. In any case, there is no practical benefit from such hybrids, while they themselves are prone to disease and early death.

…and helpful

Recently in the domestic media there have been reports of successful hybridization of a she-wolf and a dog in the kennel of the canine department of the Perm Military Institute of Internal Troops.

A significant part of the hybrid animals obtained there has well-marked signs of tolerance, that is, tolerance for humans, which means that almost the main barrier to the practical use of wolf sperm in dog breeding can, in principle, be overcome.

In addition, all wolfdogs are emotionally very restrained. They have much more physical endurance than dogs. They quickly master a platform with obstacles, a fence more than 2 meters high easily jumps from a place, shots and explosions do not frighten them. When trained, they very quickly understand and learn what is required of them, and, in addition, they undoubtedly have an excellent instinct. So, the speed of detecting a conditional offender in caches during a search of an object does not exceed one minute for them, while for dogs, 1.5-4 minutes, with a standard of up to 6 minutes.

Of course, wolf-dogs, cold-resistant hybrids of carp with Amur carp, sheep with mouflon and argali are not as impressive as ligers and tigers, but they bring more benefits to humanity than an example. And what can we expect in the future from a tiny snail - life will show.

It is, apparently, the further improvement of existing crops grown on already developed lands. Hybrids are something that can play a key role in food security. After all, most of the areas suitable for agriculture are already occupied. At the same time, increasing the amount of water, fertilizers and other chemicals used on them is not economically feasible in many places. That is why the improvement of existing crops is of exceptional importance. And hybrids are plants obtained just as a result of such an improvement.

The challenge is not only to increase yields, but also to increase the content of protein and other nutrients. For a person, it is also very important the quality of proteins in edible (including people) must receive from food the required amounts of all essential (i.e., those that they are not able to synthesize themselves) amino acids. Eight of the 20 amino acids a person needs come from food. The remaining 12 can be developed by him. However, plants with an improved protein composition as a result of selection inevitably require more nitrogen and other nutrients than the original forms, therefore, they cannot always be grown on infertile lands, where the need for such crops is especially great.

New properties

Quality includes not only yield, composition and quantity of proteins. Varieties are being created that are more resistant to diseases and pests, due to the fruits they contain, more attractive in shape or color of fruits (for example, bright red apples), better able to withstand transportation and storage (for example, tomato hybrids of increased keeping quality), and also have other significant properties for a given culture.

The activities of breeders

Breeders carefully analyze the available genetic diversity. Over the course of several decades, they have developed thousands of improved lines of the most important agricultural plants. As a rule, thousands of hybrids have to be obtained and evaluated in order to select those few that will actually outperform those already widely bred. For example, in the United States from the 1930s to the 1980s. increased by almost eight times, although only a small part of the genetic diversity of this crop was used by breeders. There are more and more new hybrids. This allows more efficient use of cultivated areas.

hybrid corn

The increase in maize productivity was made possible mainly by the use of hybrid seeds. The inbred lines of this culture (hybrid in origin) were used as parental forms. From seeds obtained as a result of crossing between them, very powerful hybrids of corn develop. Crossed lines are sown in alternating rows, and panicles (male inflorescences) are manually cut from the plants of one of them. Therefore, all seeds on these specimens are hybrid. And they have very useful properties for humans. By careful selection of inbred lines, powerful hybrids can be obtained. These are plants that will be suitable for growing in any required area. Since the characteristics of hybrid plants are the same, they are easier to harvest. And the yield of each of them is much higher than that of unimproved specimens. In 1935, corn hybrids accounted for less than 1% of all this crop grown in the United States, and now virtually all. Now, obtaining significantly higher yields of this crop is much less laborious than before.

Successes of international breeding centers

Over the past few decades, a lot of effort has been made to increase the yield of wheat and other grains, especially in warm climate zones. Impressive success has been achieved in international breeding centers located in the subtropics. When new hybrids of wheat, corn and rice bred in them began to be grown in Mexico, India and Pakistan, this led to a sharp increase in agricultural productivity, called the Green Revolution.

Green revolution

Fertilizers and irrigation developed during it have been used in many developing countries. Each crop requires optimal growing conditions to obtain high yields. Fertilization, mechanization and irrigation are essential components of the Green Revolution. Due to the peculiarities of the distribution of credits, only relatively wealthy landowners were able to grow new plant hybrids (cereals). In many regions Green revolution accelerated the concentration of land in the hands of a few wealthy owners. This redistribution of wealth does not necessarily provide jobs or food for the majority of the population in these regions.

Triticale

Traditional breeding methods can sometimes lead to surprising results. For example, a hybrid of wheat (Triticum) and rye (Secale) triticale (scientific name Triticosecale) is gaining importance in many areas and appears to be very promising. It was obtained by doubling the number of chromosomes in a sterile hybrid of wheat and rye in the mid-1950s. J. O'Mara at the University of Iowa with colchicine, a substance that prevents cell plate formation. Triticale combines the high yield of wheat with the ruggedness of rye. The hybrid is relatively resistant to linear rust, a fungal disease that is one of the main wheat yields. Further crosses and selection have produced improved triticale lines for specific areas. In the mid 1980s. this crop, thanks to its high yield, climate resistance and excellent straw after harvest, quickly gained popularity in France, the largest grain producer within the EEC. The role of triticale in the human diet is growing rapidly.

Conservation and use of crop genetic diversity

Intensive crossbreeding and selection programs lead to a narrowing of the genetic diversity of cultivated plants for all their traits. For obvious reasons, it is mainly aimed at increasing productivity, and among the very homogeneous offspring of specimens selected strictly on this basis, resistance to diseases is sometimes lost. Within a culture, plants become more and more uniform, as certain of their characters are more pronounced than others; therefore crops as a whole are more vulnerable to pathogens and pests. For example, in 1970, helminthosporiasis, a fungal disease of corn caused by the Helminthosporium maydis species (pictured above), destroyed approximately 15% of the crop in the United States, causing a loss of approximately $1 billion. These losses appear to be due to the emergence of a new race of the fungus, which is very dangerous for some of the main lines of corn that were widely used in the production of hybrid seeds. In many commercially valuable lines of this plant, the cytoplasm was identical, since the same pistil plants are repeatedly used in the production of hybrid corn.

To prevent such damage, it is necessary to grow in isolation and conserve different lines of critical crops that, even if the sum of their traits is not of economic interest, may contain genes useful in ongoing pest and disease control.

Tomato hybrids

Tomato breeders have been remarkably successful in increasing genetic diversity by attracting wild varieties. The creation of a collection of lines of this culture, carried out by Charles Rick and his collaborators at the University of California at Davis, made it possible to effectively deal with many of its serious diseases, in particular those caused by imperfect Fusarium and Verticillum fungi, as well as some viruses. The nutritional value of tomatoes has been significantly increased. In addition, plant hybrids have become more resistant to salinity and other adverse conditions. This was mainly due to the systematic collection, analysis and use of wild tomato lines for breeding.

As you can see, interspecific hybrids are very promising in agriculture. Thanks to them, you can improve the yield and quality of plants. It should be noted that crossbreeding is used not only in agriculture, but also in animal husbandry. As a result of it, for example, a mule appeared (its photo is presented above). This is also a hybrid, a cross between a donkey and a mare.