Centaurians in the world of plants
"Centaurs" in the world of plants. Achievements of Russian, European and American scientists. As the drain and all the favorite strawberry appeared. The creation of new wheat varieties. The main achievement of Russian scientists - cabstore.
Another, no less ancient way to obtain new varieties of plants and rock breeds is crossing, or, as scientists say, hybridization among themselves different species. Imagine that in the hands of the agronoma turned out to be two plants, each of which possesses some useful properties. Naturally, very tempting looks like the idea of \u200b\u200bgetting one plant, which would combine signs of both of them. How to make this idea? Of course, we traveled between both these plants. This technique began to use in distant antiquity, first unconsciously - simply selecting natural hybrids in nature from time to time, then purposefully crossing different shapes. Examples of this is a huge set. Take at least such a well-known cultural plant as a drain. Probably, few of you know that there is no such kind of plant in the wild. Plum - This is a hybrid resulting from the natural hybridization of two other species - Tern and Alychi, and combining properties and the other plant. In the mountains of the Caucasus and sometimes wild hybrids of these species can sometimes be discovered. Ordinary is also the result of interspear hybridization in nature. It appeared in ancient times from crossing cherry with a steppe cherry - a non-fried bush, not exceeding in a height of 1-2 meters.But, as you know, people are very rarely satisfied only by giving them nature. Very quickly they learned how to cross the various wild views as a result of which such hybrids appeared, which nature never knew. We list only a few examples. So, loves by all the garden strawberries (it is often wrong to be called strawberries) originated from the hybridization of two wild species of strawberries - Chilean and Virgin. And although her ancestors come from America, she was launched still in Europe. The American breeder of Burbank was widely used the interspecific hybridization. Perhaps, one of the most remarkable achievements was the creation of a four-valid hybrid of a dwarf edible rape chestnut, which gives the fruits for the second year after sowing.
A genuine sensation was at one time the creation of the American genetic church of the N. Children of the so-called short-satellite wheat. The researcher accidentally discovered in the US wheat collection extremely low wheat, which has long been grown in India. The presence of a short stem is very important quality for grain culture - otherwise, most of the nutrients goes to the rise of the stem, and not on the formation of grain. So it turned out: a lot of straw, but the grain is not very. Borloug crossed this wheat with another carlock form - this time Japanese (she managed to detect as many as three carlikoviness genes). Based on these two forms, the American breeder managed to bring together several excellent dwarf and semi-class wheat varieties, which is currently being grown throughout the tropical and subtropical areas of the globe. Just because of this, the achievement of genetics and selection managed to raise grain yields in two, and somewhere three times!
Extremely difficult, but successfully completed, there was the work of English breeders in hybridization of a wild-growing diploid form of blackberries with a tetraploid cultural blackberry, distinguished by unusually tasty fruits, but extremely late. Initially, researchers were lucky: a chance was found blackberry without spikes. But, despite numerous efforts to cross these two species, we managed to get just four hybrid seedlings and, alas, all with spikes. Among other things, three of them were triploid (that is, with triple sets of chromosomes) and, accordingly, the seeds did not give. But the last seedman was pleased with scientists - he turned out to be a fruitful tetraploid. When they waited for fruiting, sowed and raised new offspring, it was found that 37 plants without spikes, and 835 carry spikes. Of the first, one selected one and crossed with a prickly cultural variety. In a new offspring, every three plants with spikes had one without thorns. From the shattered breeders, only one plant was liked - it became the hedleacher of the famous English variety of Merton Torn Less.
However, the genuine masterpiece of selection is considered to be obtained by real plant "Centaurs" - hybrids between plants belonging not only to different types, but also to different kinds. The most famous of these experiments are the works of the Russian breeder GD Kkarechenko. As a result of a genetic experiment conducted by a researcher, a new plant appeared on the light - the cabstore. His shoots were swayed half cabbage, half-rated fruit. Let's get acquainted in more detail with the history of its creation.
Every breeder who tried to cross different types of plants knows that the most difficult is not to get a new hybrid , and ensure that he began to give seeds. After all, if the new grade cannot multiply, all works will be in vain - the resulting plant will die sooner or later, without leaving the descendants after himself. Why are the prolific hybrids - is it a very big rarity? To answer this question, we again, again, will have to turn to the mechanism of the formation of genital cells - Games. Recall that every gamet, and men's, and female arises as a result of a special cell division process called Meiosis. During MEIOS, the number of chromosomes in cells decreases, so the gamets carry exactly two times less chromosomes than the cells of the parent organism. But at the very beginning of Maiza, another very important event occurs - pair or, as scientists say, homologous chromosomes are tightly pressed together and exchange DNA pieces each other. And what will happen if the chromosomes "don't recognize" each other and can not exchange genes? And nothing - normal gametes will not be able to.
Now imagine yourself hybrid arising when crossing two different types of plants or animals. Each chromosome from a pair of homologous chromosomes in its cells comes from different organisms. In the case of cabbage and radish, each "cabbage" chromosoma accounts for one "radiant" - both of these plants are carried in the genual cells of 9 chromosomes. But cabbage genes are nothing in common with radish genes (these plants are generally related to different biological gods). It means that even if it is possible to obtain a hybrid plant (for example, by "violent" pollination of the colors of cabbage of pollen radish), chromosome "do not recognize" each other, and hybrids will be not capable of reproduction.
Is there any opportunity to get a hybrid capable of reproduction? As you know, hopeless situations does not happen. Nobody said that hybrid plants do not form grounds at all - no, they still appear, but they are not strictly defined by chromosomes (9, as the cabbage and radish relies), and random, for example, 5 or 8. means There is a very small probability that goveta with 18 chromosomes - 9 cabbage and 9 rally chromosomes will be in the same cell. From the mass of cabbage crossings with radish, ended in failure, in one case Karpechechenko received a plant that grew up and even bloated, after which the scene of the one-mounted seed. This was the happiest case: all 18 chromosomes got into one Games.
An unusual Gameta accidentally met with Gamena, also carrying 18 chromosomes, as a result, a plant with 36 chromosomes increased, that is, the usual single set of 9 chromosomes was repeated 4 times (we already know that such plants are usually called tetraploids). Thus, here we are again faced with the already familiar with the phenomenon of polyploidy - increase the number of chromosomes. The division of cells and the formation of Games from this hybrid has passed safely - each of the nine-wheeled chromosomes now found a couple of themselves, the same thing was with the cabbage chromosomes .. the offspring of such organisms were given. When the first hybrid plant has grown out of the seed, its nature manifested itself in the most amazing way: half of the fruit turned out to be the cabbage, and the other half is height. Cabstormochka completely justified its name. But Karpechechenko did not stop at the achieved. Games of the obtained hybrid, he connected with a normal radiant games. Now the radar chromosomes turned out to be twice as low as the cabbage, which did not slow down to affect the fruits: two thirds of each fetus had a rarest shape and only one third - cabbage. So thanks to the polyploidy, for the first time, they managed to overcome the natural slope of two different clans.
The list of plant "Centaurs" is not limited to cabbage-oscillating hybrids. Thus, as a result of crossing two grain crops - rye and wheat - scientists received a number of forms united by the common title name. Triticale has good yields, winter hardiness and resistant to many wheat diseases. Thanks to the hybridization of P. chenicy and malicious field weed - Pouring - breeders received valuable plant varieties - wheat-flowered hybrids resistant to lodging and possessing high yields. Another famous Russian breeder - I.V. Michurin - crossed the Pennsylvanian cherry (very frost-resistant, in contrast to the cherry usual usa) with a cherry and synthesized a new plant, which called Ceramapadus. Only later later it was found that cerapads spontaneously arise on the Pamir, but a little different.
In the Getya times, as Guete himself recalled, in Carlsbad - do not look for a map, now it is Karolovya - on the waters, holidaymakers loved to determine the plants in the bouquets on Linne. These bouquets drinking mineral waters in the shadow of the colonnade (sodium bicarbonate-sulfate-sulfate-sodium - to the information of going to Karlovy Vary) delivered a young beautiful gardener daily, causing the pale lonely ladies increased interest.
The correct definition of each plant was the matter of honor and success at the gardener who encouraged innocent botanical hobbies for a modest fee. It is difficult to say why - because of the jealousy whether to the gardener, or to Lynne, but the poet stiffedly spread with Linnese in the principles of plant systematics. Linno, as you know, I was looking for a distinction in plants, Goethe began to look for the general and, I must say, took the first step towards the genetic systematization of plants.
The passion for women by Botanya could be understood: Linnei's system was simple and understood. This is not the "determinant of higher plants of the European part of the USSR" Stankov-Talieva more than a thousand pages, leading students in the pre-infarction state.
Linney, I have not loved the arithmetic software, nevertheless laid it, you can say the basis of my system. He divided the plants on the 24th grade, of which 13 are highlighted by the number of stamens. Plants with one sticky in each flower are placed in the first class, with two - in the second and so on to the tenth class, to which plants are attributed to ten stamens. Class 11th included plants with 11-20 stamens, 20 and more stamens in the flower spoke of belonging to the 12th and 13th class. These two classes distinguished in terms of the location of the base of the stamens relative to the place of attachment of the pestle. Plants of the 14th and 15th grades have non-long-length stamens. In the colors of classes of the 15-20th stamens in plants, they are smashed among themselves or with a pestle. In the 21st grade, one-bedroom plants were placed, having a part of the latch, part of the flourling (pestile) flowers. In the 22nd class, two-walled plants, developing on some plants, only sticky, on others - only fluttering flowers. Class 23rie included plants with chaotic scattering of male and female flowers (including sometimes and collaborated) on the plant. In the 24th grade, "creeping" plants were combined - all the inceptuous plants, starting with fern-shaped and ending with algae. Named the last "tinarial" for the reason that nerds did not know how they breed. It is now biologists are known for their organization and reproduction better than flowering plants.
Linno, in addition to 20 out of 23 classes to the obnunarious ripples. It was them that he counted the rule in the plant kingdom, the rest - a curious exception. It seems to be logical, for plants more convenient - stamens and pestles near, it means, marriage without a hitch; The result of love - the fruit and the seed appear as a result of self-pollution encrypted by the biologists of the Latin word Autogamia.
Already after Linneya, it turned out that some plants only seemed to look like rims. Although they have in the flowers near and stamens, and pestles, but pollen cells in anthers are underdeveloped and the whole plant eunuch eunuch - watch disgusting. Other flowers themselves cannot be fertilized, but their pollen is capable of producing offspring in pollution of the pestles of other people's plants.
Since the botany began to call everything with Latin names, the aggregate of the flower stamens, they called Andrzem, and the totality of pestles (or just a pestle) - guinesem. But since no scientist on the already achieved one day no longer stops, then Botanists later, depending on the structure of the flowers, they divided them into common drops (contain Androz and Ginnets) and same-sex (contain either Androz, or Ginnets). If male and female flowers bloom on one plant, it is called one-bedroom (corn), if on different - dwarm (hemp). In polygamic species on one plant there are rim and same-sex flowers (melon, sunflower). However, apparently, in the peak, the nerds sometimes substitutes to the inquisite OKU, all forms of transition from one sexual type of flower and plants to another, up to empty-flowers, completely devoid of stamens and with underdeveloped pestles.
Extremely annoying gardens weed moc. Mocrica, or Toptun, has ten stamens in two five-colored mutters, of which 5 internal with some addition of such an external muve are shrinking and pollen are shred. Flower heads of the black head (Poterium Polygamum) contain other than purely fluttering and purely sticky flowers. There are also real ripple flowers. They represent all examples of the transition from real robes to the flowes of pure maternal type. By the way, this botanical race is exceptional among the rustling of its tendency to the winding.
Also, the degree of separation among the false-precipient fruit and sticky flowers is also diverse. Bodyak, asparagus, persimmon, grapes, some scabiosa, stamps, Valeries have flowers at first glance. They are well developed pestles, visible and stamens, in anthers of which can or absent pollen. In the latter case, these are false bevel flowers. What to do, and in the nature of "Lhadmitry" meet. The same can be said about the part of the flowers in the brushes of horse chestnuts and some species of sorrel, as well as in the flowers in the center of the basket of coltsfoot and marigolds, having the type of real hawk flowers, but whose wounds do not give the chassis seeds, as the stitch It is not able to pass through the pollen tubes.
In the brushes of Japanese (one of the types of maple), you can see all possible transitions from false-minded pulp flowers with well-developed major barriers to such in which pestles are underdeveloped or completely absent. Transitions from real robbery flowers to empty vehicles can be found in several types of steppe hyacinth.
Three-dimensional species are also known: they have only the plants carry only men, others - only female, and the third are routine flowers (Smolevka). From the curiosities of plants, you can note the change of floor with age or in some years. Grapes heart-shaped, referring to its homeland to typically digestively, in the Vienna Botanical Garden is represented by bushes with stitching flowers. But in some years, grape bushes lead excursions into confusion, since the real ripple flowers are formed.
In many plants, self-evisition is hampered by the unlimited maturation of the stamens and pestles in a flower - dikogamia (sunflower, raspberry, a pear, an apple tree, plum), in which they distinguish between the protender, when the stamens dust before the ripening of pestles, and the protesting when the pestles ripen the stamens.
Mainly proterandrichny complex color, lubber, malvic, cloves and legumes; Proterogounds Sitnies and vessels, kirkazonovy and dafnes, housing, globular, grated, rose-colored and cruciferous. Waterfront All Single Rest Plants: Dies, Rogozes, Economics, Awnings with Single Drugs, Corn, One-Doma Nuts, Uphew, Cherhead, Doughnik, Mad Cucumber, Ruisen Plants, Olha, Birch, Walnut, Platan, Elm, Oak, Oshnik, Beech . In the trees named here and shrubs, anthers begin to dust late for 2-3 days. At the Alpine green alder, this difference is 4-5 days, and in small Rhoze - even nine.
Most of the watered bombing plants. In large ventilators, some species are still represented by numerous shrubs on the latter chestings of our rivers. Piece of them carries the tight flowers, the other is pestle. They are practically in some conditions, but despite the same external conditions in the same area, bushes with birds with pesting flowers are always cleverly ahead of the flowering of their "men" with stitching flowers. Belotala, a purple slot, a basket of willow and ripples of a stroke in their ripening for 2-3 days ahead of the opening of the sticky flowers. The same in the Alpine Yves - make sure if you have visited the Alps. But then the time difference is limited only to one day, from which it is legitimate to conclude that our willows are the most protothelichichny willows in the world.
In plants, cannabis growing nearby, at the beginning of blooming, you can see the stilts ready for the perception of pollen, although neither a single stitching flower is not yet disclosed - they will reveal only after 4-5 days. The proleski, or seelings growing on deciduous forests and shrubs, nearby maternal and fatherly individuals nearby. Nevertheless, pestile flowers are opened two days before the stagger. The same at hops and many other downtime plants.
In a few plants, self-evisition is difficult because of this location of the stamens and pestles, in which pollen is difficult to get on the pistil of his flower. For example, with heterostilia, some individuals have flowers with long pestles and short stamens, while others - on the contrary. The heterostille (multiple) includes some advocate (for example, watch, or a shader), buckwheat, various types of lazz, numerous original (for example, bars, turcha, primula, or primrose), as well as many burst (forget-me-not, median, etc.) .
The watch has very elegant shaggy blore flowers-asterisks, collected by a brush on a light-free stem. Some flowers have a low column and strengthened in front of him, others, on the contrary, are high columns and strengthened dustners. Frames in the plant ripen before the stamens. Insects attending the Watch flowers relate to the same part of their body of pestles, then the stamens, carrying out strictly cross pollination. However, in a long bad weather, the flower is closed and forced to self-evisition.
Introduces, among children are better known as the beaches, blooms the flowers of one of the first among spring colors. Hence the Latin name Primus - the first. Fill the plant only bumblebees and butterflies. Thanks to the multipleness of the pestle of some flowers can be pollinated with pollen only from other flowers. If the bumblebee sits on the flower with a low pestle, it concerns the head of the high-couplings. Flying to a flower with a high pestle, it concerns the head of the stitch and produces cross-pollination.
The phenomenon of the difference in the first time was open on Turch Flowers Bolotnaya, and then on other plants. Turchi's championship in this regard seems even incredible, if we consider that all the plant is immersed in water, and only in July flowers appear above the water. The other notion of Turchi is that it does not have roots, and the suction functions are performed by the cells of the leaf skin.
At buckwheat, according to the abundant assurance of genetics, long-fiftyment is controlled by a recessive allele S, and a shortburdenness - the dominant allele S (remind that the allele is one of the forms of the same gene). Since pollinations within one type of flower does not occur, in populations all the time an equal ratio of plants with SS and SS genotypes is maintained; This can be seen from the lattice of Pennet, known from the school biology course:
that is, splitting 1: 1, like a person, on boys (at) and girls (XX) in the offspring.
In structure, buckwheat flower is adapted to cross-pollination predominantly insects (flies, bumblebees and especially bees), which attracts nectar, and only in part - the wind. With normal (legitimate) pollination, when the pollen of the short stamens falls on the stilts of short columns and, accordingly, the pollen of long stamens - on the stilts of long columns, the largest number of seeds are tied.
Plakuan-grass (Lythrum Salicaria) is one of the most interesting plants. The fact is that the flowers of the grass-grass have pestles of three different quantities and 12 stamens located equally in two circles. In some flowers, the pestle is higher than both laps of the stamens, in others - it is between them and thirdly - below both laps. Consequently, the stamens are located at various heights as well as pestles, which ensures cross-pollination. The insect, arrived at the nectar, is embroiled with pollen and gives it on the pistil's stil, along the length of the corresponding twin, with which the pollen is removed. Fertilization occurs normally when pollen is transferred from the stamens, the same in length with a pestle. The grains of pollen from the stamens of three different heights differ in size in size and partly in color, and according to the length of the papillars on the stilts of three different heights are also different, because the stilts must capture different pollen. The process of pollination in the details was first studied by Ch. Darwin.
Some plants of stamens and pestles are located in a strict sequence, substituting insects for the "unloading" of pollen or "loading" of the still. Our rude ordinary, found on the slopes and hills in the forests of the South Crimea, the flower contains ten anthers supported by straight straps. At first one thread rises, arranging the boot supported by it in the middle of the flower along the line leading to the nectar, which is highlighted by a fleshy ring at the base of the pestle. It saves such a position for about a day, then returns to the previous position. While the first stitch is rejected, the other rises - and everything is repeated. It continues until all ten anthers, one by one, is not at the middle of the flower. When, finally, the tenth stitch will be back, in the center of the flower, it turns out to be a stall, which has become susceptible to pollination at this time.
In the rippled flowers, the Penchedties from the Family of the Nature Style develops even before the flower is dissolved and the first is the first flower from the greenish booth. Anthers on the bent legs, as if on the springs, closed with closing small greenish bumps. But before they allow anthers to climb from "knees", straighten up and dispel their pollen in the form of a cloud in the air, the snaps of faded and the column is separated along with a snag from Zagazi. So by the time of the liberation of pollen from the anthem, the wound up with the edge - dried the base of the fallen column.
Usually, the plants all this happens differently: first in the flower, anthers and stamens fall in the flower, and only after that, the stroke acquires the ability to perceive pollen. In Balzamine flowers, anthers are accumulated among themselves and form something like a cap over a stitch. After the flower revealed and became available arriving insects, the anthers immediately crack, and the cap formed by the caps educated by the depressions. But the threads are separated, and the cap falls out of the flower. Only now the strokes are shown, quite ripened. The same can be observed among the large-flowered types of chewing and geranium.
In richer flowers of tradesansans, bred at home and at a misunderstanding called "Balay Glotes", anthers open a little earlier than the stilts will become susceptible to pollen. But as soon as the stil is ready to pollinate, the stamens are coagulated in the spiral, and soon they fade the stokers covering the anthers on the curled threads. The column is issued, and the stilts are susceptible to pollen on the whole day. These flowers visit insects with short trumps to enjoy the juice of crumpled bumps, hiding stamens, while they concern the fishing and pollinate their pollen brought from other flowers. It is no longer possible to pollinate the pollen of their dust.
Dichogamia Botany, based on their research only on morphoecological differences, without taking into account the content of genomes, is obliged to abundance of the species of the OSK, infinitely re-opened, and even those reversed. Moreover, the so-called "species" of the Oskock is easily crossped with each other, issuing many intermediate forms who are eagerly taken for new "types" (authors of species attract the opportunity to perpetuate their name in Latin transcription). The imperfect (incomplete) dichogamy in botanical genera with monocotted flowers provides, for example, the OSK at first the so-called interspecific, and later intraspecific crossing. This is understandable, since the deer of the first flourishing plant of the protrusion can only be polled by the pollen of others, even earlier the blooming "species".
Lysenko believed that "Dialectic materialism, developed and raised to a new height of the work of Comrade Stalin, for Soviet biologists, for Michurinsev is the most valuable, the most powerful theoretical weapons in solving deep issues of biology, including the question of the origin of some species from others. . Therefore, it is given to them the ultra-dealectic definition of the species at this new height: "The view is a special, qualitatively definite state of living forms of matter. An essential characteristic feature of plant species, animals and microorganisms is certain intraspecific relationships between individuals. " That's so.
Not all nerds wish to see that in the dialectical unity of the form and content defining is the content. The content of the species is the unity of the genetic structure of populations, its components. Externally, it is manifested in the phenotypic similarity, free crosseability, especially in the ability to give a prolved offspring when crossing. Hereditary information is that this is what qualitatively determines the appearance of its content. It is difficult to say whether life arose simultaneously with heredity (I suspect that at the same time), but one is not in doubt: the appearance of discrete heredity appeared on the globe.
Taking into account the known science of the wording, the definition of the form may be: the species is a qualitatively isolated at this stage of the evolutionary process, a complex and mobile community of organisms, characterized by the unity of origin, the generality of the genetic constitution, the hereditary stability and fertility of the offspring. Most of the selected "species" of the OSK and Yves do not correspond to this definition.
In the allocation of "good", or real, species on crosses and the formation of fruit offspring, it is impossible to forget about the phenomenon of self-observance - the impossibility of self-extinguisability in some hermaphroditic organisms or cross-fertilization between individuals of the species with the same genetic incompatibility factors. The main function of self-control system systems is to prevent self-evisition and promoting crossing between unreold features.
Split a gametophyte, spore and heteromorphic self-absoluteness. Gametophyte self-absoluteness is the most common (cereal, beets, alfalfa, fruit, potatoes, etc.). This system is characterized by an independent action in the pollen and the column of two alleles of the incompatibility of S. present in each individual. For example, the pollen of the plant with the genotype S 1 S 2 behaves like S 1 or S 2, depending on which allele contains pollen grain. None of the alleles exhibits dominance or other form of inter-allegant interaction. The same complete independence is observed in the column.
The incompatibility reaction is manifested in the pistil column: the growth of pollen tubes carrying this allel is stopped in columns containing an allele allele. If all alleles participating in hybridization are different, for example s 1 s 2 xs 3 s 4, then all pollen tubes are compatible, the marking is obtained normal and 4 cross-compatible genotypes are formed in the offspring. In the huge majority of the studied species of hametophyte incompatibility, one or two locus is controlled.
Sporophyte incompatibility was first described in Guyuly. With the spore self-combativity, the behavior of each pollen grain depends on the genotype of the column. So, if S 1 dominates over S 2, the entire pollen of the plant S 1 S 2 will respond as S 1 and can penetrate into the columns carrying the allele S 2, regardless of the genotype of the pollen tube - S 1 or S 2.
Heteromorphic incompatibility arises on the basis of heterostilia already described by us earlier.
One of the fixtures of the plant for the implementation of cross-fertilization serves men's sterility. In recent decades, men's sterility in cultivated plants causes great interest among breeders and seeds, as it makes it possible to obtain heterose-free generation hybrids widely, which give rise to 40 percent in relation to ordinary varieties, differ in early and friendly maturation, high leveling and Resistant to adverse environmental factors.
To date, cytoplasmic male sterility (CMS) and gene men's sterility (HMS) controlled by the gene nucleus genes are described. Cytoplasmic men's sterility in plants is due to the interaction of sterile cytoplasm (S) with 1-3 pairs of recessive kernel genes (RF). In the presence of dominant genes of kernel (RF) fertility of pollen is restored. The CMD is widely used to obtain heterosexis hybrids on an industrial scale in corn, sorghum, sugar beet, onion, carrots. Usually,
for the use of the CMS in the seed hydrodium of the first-generation hybrids (they are designated F 1) use fertil sterility secrets with the NRFRF genotype (N is normal cytoplasma), their sterile analogs - SRFRF and fertility reducing agents - RFRF.
Genid men's sterility is used to obtain heterose seeds at tomatoes, pepper, barley. In the production of hybrid seeds based on one recessive GMS gene, splitting in Fi goes according to Mendel in a ratio of 3 fertile: 1 sterile plant, since, unlike the CMS, male sterility is transmitted both through women and through men's games.
Crossing, as you know, are widely used in seeds and seeds of plants. The possibility of artificial receipt of hybrids for the first time suggested the German scientist R. Charryus in 1694, and, as it often happens, no one believed him. Only in 1760, the German botanist and an honorary member of the St. Petersburg Academy of Sciences Josef Kölreyter received a hybrid of Peruvian Tobacco Miscelred with Machore. From this year, scientists begin conscious hybridization.
Depending on the degree of kinship, the crossed forms distinguish between intraspecific and remote - interspecific and interhove hybridization. If two parents are involved in crossing, they talk about simple, or pair, hybridization, if more than two are about complex. There are straight (a × b) and inverse (in × a) crossing, wearing the name of the reciprocal overall. Crossing hybrids with one of the parents, for example (A × b) × a or (and × c) × B, called a beccossom, or a refundable.
To designate hybrids and parental forms, symbols are used: P - parental form; F 1 - hybrid of the first generation; F 2 - second, etc.; In 1, or aircraft 1, - the first generation of Beckcross; In 2, or Sun 2 - the second, etc. The mother form is indicated by the icon ♀, fatherly - ♂. However, it is most often costs without the latter, putting a maternal form in the first place in the recording of the crossing combination, and the father-to-second.
Methods and techniques of crossing depend on the biology of flowering and pollination, fertilization, features of the structure of flowers (rigging, separation), the location of the latter on the plant and in inflorescence, from the method of pollination, the duration of preserving the viability of the pestle and pollen and the conditions of crossing.
Breeders use forced, limited free and free crossing, for the implementation of which is often needed by castration of plants. Castra is to remove immature anthers or damage to cutting, thermal sterilization (hot air or water) or chemical castration - the use of specially selected gametocides.
In case of compulsory crossing, neutered and isolated maternal plants polluted by the pollen of the father's plant. With free crossing, parental forms are sown with alternating rows. Castrated, menusterile or biologically women's maternal plants are pollinated by the pollen growing near the father's plants.
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It is called sexual crossing of two individuals, differing in a large or smaller number of features. They can belong to two varieties, races, varieties of one species, to two types of one kind or different kinds of one family. In most cases, the more close to each other crossed individuals, the more chances to get viable and prolific offspring.
Sex hybridization is of great importance and use in practical crop production. Many of our cultivated plants, as already mentioned, are sexual hybrids, partly in common in nature and taken from there in culture, partly derived by artificial crosses.
The ability to sex hybridization in some families or individuals and species of them turns out to be greater, in other less. Sometimes hybridization is not possible between morphologically close related species, whereas between more distant.
The most easily carried out by sexual hybridization between varieties and varieties belonging to the same type. The hybrids between the species are obtained mostly small, few viable and non-visible in the future; Hybrids between childbirth are obtained much less often and in the future in most cases there are fruitless.
Research I. V. Michurin showed that the infertility of hybrids in many cases is temporary.
Often, when crossing, the first generation of hybrids is distinguished by extremely powerful development, exceeding its size several times parental forms. This phenomenon is called heterogeneous. In the offspring of hybrids obtained by sexually, the plants are usually returned to the previous sizes of their progenitors. But if such gigantic hybrids can breed vegetatively, then the obtained giant will manifest itself in vegetatively derived offspring. In this way, large varieties of root and tuberplods can be removed, decorative trees and herbatous plants With very large flowers, etc. It is also possible an annual new removal of annual heterosexis plants to increase their products, for example, tobacco, tomatoes, corn, etc.
In some cases, infertility of hybrids is possible with the help of planned subsequent crossings to restore fertility.
When crossing sex hybrids different species Together with each other managed to obtain forms that are hybrids between 3, 4 and more species.
The question of dominance is the prevalence in the hybrid of certain signs of parents or their ancestors - is the most important issue in selection, in the relevance of new varieties.
I. V. Michurin believed that the hybrid does not constitute something mean between manufacturers. Heredity of the hybrid is composed only of those signs of plants producers and their ancestors in the early
the stage of development of hybrid is favored by external conditions. The dominance of certain signs also depends on the detailed force of manufacturers in the sense of transferring to the offspring of their signs. Signs are more transferred to a greater extent: 1) species growing in a wild state; 2) older by the origin of the variety; 3) older at the individual age of the plant; 4) older flowers in Krone. Mother plant, with other things being equal, will fully transmit its properties than fatherly, but if the conditions for growing hybrids will be more favorable for the father's plant, its signs can dominate.
Plants, weakened drought or cold spring, have a weaker power of transferring their hereditary properties.
To overcome the undertocativeness of remote systematic species I. V. Michurin, developed a number of effective and very interesting methods in general biodicals.
The mediator method lies in the fact that if two any species do not cross each other, then one of them cross with some third, with which both of these kinds can be crossed. The obtained hybrid is the "mediator" - has a greater ability to crossbow, and it is possible to successfully intersect with the second of those species that have been planned for cropping. This method I. V. Michurin used when crossing wild almonds (Amygdalus Nana.) with peach; Intermediary here was a hybrid received from the crossing of wild almonds with the North American peach David ( Prunus Davidiana.). Further studies have shown that such complex hybrid forms have a wide ability to cross-country with such species that their initial parents do not cross.
The method of "vegetative convergence", used by I. V. Michurine to overcome undisguisedness, is that the young seedman of one of the plants to be crossed in the crown of another, adult plants, with which it is desirable to cross it. This seedler, unstable, as not a formed organism, gradually changes to the pore of flowering under the influence of a more powerful stock, approaching the properties to it and cross it in the future better than the initial form without vaccination. By this way, I. V. Michurin used, for example, with hybridization of apple and rowan with a pear.
The method of using pollen mixture, also facilitating crossing, consists in mixing a small amount of pollen of the maternal (pollinated) plant to pollen pollinating plants. Presumably, the pollen of his species makes a snack more susceptible to pollinate to pollen. These methods are currently widely used in breeding work with a variety of plants. It is also used to mix the pollen of a third form or a variety, which can also stimulate pollination of pollen, without this reception does not give results.
A large role in the works of I. V. Michurin played the upbringing of young hybrid seedlings with unstable heredity. Remote hybridization without further directional education often does not give desirable results. The directional impact on the hybrids is achieved by various methods, including by vaccinations, or by the method of the mentor, in which the hybrid has a reinforcement of some properties. The Mentor Method is based on the mutual influence of the flow and the lead. It was used by I. V. Michurin in two versions. With the so-called
the stalk of the young hybrid seedlings in the crown of the young hybrid seedlings in the crown of the adult producers of it, the quality of which (for example, frost resistance) is desirable to strengthen in a hybrid. The graft hybrid under the powerful exposure to the bond (coaching mentor) acquires a more desirable hybridizer property (in this example, frost resistance). Or, for example, a seedling, a hybrid between the drain renclode is green and the tern, eyes were taken and grafted: one on the renclod, the other to the turn. In the first case, there was a plant with the signs of renod (renclode of the thorns), in the second case with the signs of the Tern (Tern Sweet). The opposite effect of the lead on the dating is affected in the so-called vaccine mentor, when, for example, in the crown of a young seedlings, several cuttings of the old grade (vaccination mentor), which differs from abundant fruiting, can accelerate and improve the fruction of the stock; With other combinations of the planting plants, this method was possible, on the contrary, to delay the ripening of fruits, lengthen their ability to be stored in a knee and so on.
These new principles and methods of work, open by I. V. Michurin, are important. Selection of couples in hybridization by pre-biological analysis of parents, directional education of hybrids, accelerating the deadlines for the removal of new varieties - all this is widely used in the excretion of new varieties of cultivated plants.
By crossing solid wheat ( Triticum durum) with soft ( Triticum vulgare.) Some new valuable wheat varieties have been obtained. Rust-wheat hybrids are obtained, which are of interest in themselves and for further crossings again with wheat, in order to obtain hybrids with high quality wheat grain and ore-resistant rye. Work is underway on wheat crossing with wild drinking (N. V. Tsitin), with many years of wild rye. By crossing potatoes with wild roses, potato varieties are obtained, resistant against damage dangerous for potatoes fungus - phytoofluoro. Works are underway on the crossing of annual sunflowers with perennial, sugar cane, which has a very long period of vegetation, with wild rods of it, having a smaller growing season, divorced watermelons with drought-resistant wild rings, etc. Systematic management of plants development (and animals) and the creation of new The forms of them, based on a deep study of complex biological relationships and the opening of the patterns of life, constitute the theoretical basis of the Soviet selection.
We will tell how to cross the two varieties of one type of plants among themselves - this method is called hybridization. Let it be plants of various colors or differing in the shape of petals, leaves. Or maybe they will be distinguished by flowering timing or requirements for external conditions?
Choose plants that quickly bloom to speed up the course of the experiment. It is also better to begin to choose unpretentious flowers - for example, on-line, calendulas or dolphiniums.
To begin with, specify your goals - what you want to get from the experiment. What desired signs should be new varieties?
Get a diary notebook, where you will write down the goals and will fix the course of the experiment from the beginning to the end.
Do not forget to describe in detail the starting plants, and then the obtained hybrids. Here is the most important point: plant health, growth intensity, size, painting, aroma, flowering time.
In our article, the flower will be considered as an example, you see it in the diagram and in the photos.
The appearance of colors in different plants can differ significantly, but mostly equally.
1. Start by selecting two plants. One will fatal, and the other - seed plant. Choose healthy and strong plants.
2. Carefully follow the seed plant. Choose a unspacial bud with which you will spend all manipulations, mark it. In addition, it will have to isolate before opening - Touching it in a linen light bag. As soon as the flower starts open, cut all the stamens from him to avoid accidental pollination.
3. As soon as the seed plant flower is completely revealed, transfer to him pollen From the pollinator plants. Pollen can be transferred with a cotton wand, tassels, or pulling out the flimer flower stamens and bring them directly to the seed. Pollen apply a seed plant flower pestle.
4. Put on the flower of the seed plant linen bag. Do not forget to make the necessary marks in the observation diary - about the time of pollination.
5. To progress, after a while, repeat the operation with pollination - for example, after a couple of days (depends on the flowering time).
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Choose two flower - one will serve as a pollinator, another plant will become seed. |
Immediately, as soon as the flower of the seed plant blooms, cut all the stamens from him. |
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Apply pollen taken from a pollinator flower, on a pestle of a seed plant flower. |
Fullarted flower must be labeled. |
1. If pollination has passed successful, Soon the flower will start slugging, and the wound will increase. Do not remove the bag from the plant until the seeds are matured.
2. Seeds obtained land as seedlings. When you get young hybrids plants, then highlight them a separate place in the garden or transfer them to the boxes.
3. Now wait for hybrids flowering. Do not forget to describe all observations in the diary. Among the first, and the second generation, there may be flowers exactly by repeating parent properties unchanged. Such instances take off immediately. Check with your goals and select among the new plants obtained Those that are most suitable for the desired signs. You can pollinate them either manually or isolate them.
If you decide to engage in new varieties seriously, you will be needed to advice a breeder specialist. The fact is that you will need to find out if you really have brought a new grade or go to someone who has already been laid by someone. Competition in the field of creating new varieties is very high.
The same one who decided to experiment with hybridization as a home hobby, we wish to get a lot of pleasure from this classes, make a lot of joyful discoveries and finally give all your friends to gardeners a new variety of some wonderful flower called by your name.
In the 30s. past century N.I. Vavilov noted that the problem of creating disease-resistant varieties of crops can be unleashed by two ways: selection in a narrow understanding of this word (selection of resistant plants among existing forms) and with the help of hybridization (crossing between different plants). Methods of plant selection on immunity to pathogenic organisms are not specific. They are modifications of ordinary breeding methods. The main difficulties in creating immune varieties are the need for simultaneous accounting for plants and harmful organisms that damage them. At the moment, all generally accepted modern methods of breeding work are used in the selection for stability: hybridization, selection, as well as polyploidia, experimental mutagenesis, biotechnology and genetic engineering.
One of the main difficulties in selection of plants on immunity is the genetic adhesion of signs of plants, which reflect their phylogenetic history in the conditions of natural ecosystems. In the process of spontaneous domestication and formation of highly productive and high-quality plants, the system of their immunity was weakened. In cases where the selection is ignored to immunity, the weakening of the latter takes place and in our time.
The most important task of selection, genetics, molecular biology and is to search for the combination of high productivity and other economic values \u200b\u200bof plants with signs of their immunity. It is desirable that the base of immunity is polygenic.
The most simple question is solved when from the population of the existing variety it is possible to distinguish plants that are distinguished by high immune resistance to one specific pathogen. For such a discharge, different methods of selection and analytical methods can be used, which take into account the heterosis of the variety population.
In the preparation of breeding programs, the type of pollination of the plant population (cross, self-polling or population refers to an intermediate group) is very important. Selection work on immunity to the pathogen should be carried out taking into account the following factors: in the plant population of the first group, a single plant is a separate plant, another population (grade or line).
Selection. As in general in nature and in the breeding activity of a person, the selection is the main process of obtaining new forms (formations of species and varieties, creating breeds, varieties). The selection is the most effective when working with cultures self-populators, as well as plants that breed vegetatively (clone selection).
In selection for stability, the selection is perfectly used in itself (there is a basic method when working with necrotrophic pathogens), and as a component of the selection process, without which it is generally impossible to do with any methods of selection. In practical selection, two types of selection are used for stability: mass and individual.
Mass selection It is an oldest method of breeding, thanks to the varieties of the so-called folk breeding, and is still a valuable source material for modern breeders. This type of selection in which a large number of plants are selected from the initial population in the field, appreciating the sign of signs (including resistance to certain diseases at once). The crop of all selected plants is combined and seeded in next year in the form of one site. The result of mass selection is the offspring of the total mass of the best selected on a certain sign (signs) of plants.
The main advantages of mass selection is its simplicity and the ability to quickly improve a large amount of material. The disadvantages include the fact that the material selected by massive selection cannot be checked with offspring and determine its genetic value, and therefore, to highlight a variety or hybrid-valuable hybrid in a selection form and use them for further work.
Individual selection (Pedigri) - One of the most effective modern selection methods for stability. Hybridization, artificial mutagenesis, biotechnology and genetic engineering is first suppliers of material for individual selection - the next stage of breeding work, distinguishes the most valuable material from the material provided.
The essence of the method is that separate resistant plants are taken from the initial population, the offspring of each of which in the future deteriorates and are studied separately.
Both individual and mass selection can be disposable and reusable.
Disposable selection It is mostly applied to the selection of self-polishing cultures. Disposable individual selection provides a sequential study in all units of the selection process, selected once on a certain sign of the plant. Disposable mass selection more often and most effectively use to improve the variety in seed-flow practices. Therefore, it is also called healing.
Multiple selections Perfectly and effective in selection of cross-pollinating crops, their effectiveness is determined primarily by the degree of heterozygency of the source material. By multiple mass selection, resistance to necrotrophes - pathogens such as fusariosis, gray and white rot and others are maintained. With the use of this method, highly resistant to and is created.
Hybridization. Currently, one of the most used methods in selection for stability is hybridization - crossing the genotypes with various hereditary abilities and obtaining hybrids in which the properties of parental forms are combined.
In selection for resistance to diseases, hybridization is suitable and effective if at least one parent form is a carrier of hereditary factors capable of ensuring the genetic protection of a future variety or a hybrid from potentially dangerous strains and races of causative agent.
As noted earlier, such hereditary factors (effective sustainability genes) were formed in the centers of the relative evolution of plants-owners and their pathogens. Many of them have already been transferred to cultural plants from their wild-growing relatives with remote hybridization. Now they are known as the henges of the stability of cultivated plants.
But the indisputable fact is that today most of these genes are widely used in breeding and preferably lost the effectiveness overcome by the variability of pathogens. therefore internal hybridization (Between plants of one species) when creating varieties-resistant varieties or hybrids in some cases is a low-prospective. To obtain positive results, the breeder, involving those or other parental forms in crossing, should be confident in the high efficiency of their sustainability genes to the disease pathogen in the place of the future growing of the variety (hybrid).
Against this background, more increasing importance in selection for stability acquires remote hybridization (between plants from different botanical taxa). After all, the most pronounced immunity is characterized by plants of wild and primitive species. The genomes of wild-growing congor of cultivated plants were and remain the main natural source of sustainability genes, including integrated immunity. Crossing cultivated plants of existing varieties with wild species usually makes it possible to increase immunogenetic properties. And if earlier, the use of remote hybridization was not too popular due to the difficulties associated with the imbalance of genomes of parental forms, the adhesion of sustainability with undesirable signs of economic attitudes, then currently developed methods that allow solving problematic issues.
Remote hybridization makes it possible to transmit from wild-growing plants by cultural environmental plasticity, resistance to adverse environmental factors, diseases and other valuable properties and quality. Based on the remote hybridization, varieties and new forms of grain, vegetable, technical and other crops are created. For example, the source of genes of the wheat wheat, and is the endemic for the Transcaucasus Triticum. dicoccoides. Korn..
As evidenced by the global practice, a very effective type of hybridization in the selection of self-polishing crops for stability is return crossing (Beckcross) When the hybrid is crossped with one of the parental forms. This method is called by the method of "repair" of varieties, since it allows you to improve a certain variety according to a particular feature that is missing (in particular, resistant to a certain illness). But it should be borne in mind that the use of this method does not allow exceeding the productivity of a variety that "repaired" (and according to the requirements Public service On the protection of rights to the varieties of plants of Ukraine, the variety cannot be registered if it does not exceed the standard in terms of performance).
As a rule, during biscositions, the donor-resistance variety donor is used as a maternal form, and an unstable, but highly productive variety (resistance recipient) - as a parental form. As a result of their crossing, hybrids receive, which re-cross with the parental form (becken). The prerequisite is that maternal forms for each next becross are selected from stable hybrid plants of the previous crossing found on an infectious background. The offspring are selected through the phenotype of the recipient. Beccosts are carried out until the genotype and the recipient phenotype almost completely restrict, while at the same time gaining resistance to the disease characteristic of the donor.
Improving the efficiency of plant selection on immunity to pests can be achieved when using pre-created so-called immunity synthetics (known, for example, for corn). These synthetics are created on the basis of crossing 8-10 immune lines characterized by various ecological plasticity and composition of immunity factors. Many of the synthetics are good sources to create immune lines with further conclusion of simple and double interlinear hybrids.
Mutagenesis. In contrast to methods of hybridization, quite laborious and require many years of work to achieve the final result, experimental (artificial) mutagenesis allows for a short period to increase the variability of plants and obtain such stability mutations that are not found in nature.
The basis of the method of experimental (artificial) mutagenesis is based on the plants on plants of various physical and chemical mutagens (ionizing, ultraviolet, laser radiation, chemicals), as a result of which mutations are arising in vegetable organisms (changes in the molecular structure of the gene), chromosomal (changes in structures chromosome) or genomic (changes in chromosomes).
The most valuable gene mutations in the selection plan, which, unlike chromosomal, do not lead to the sterility of pollen, infertility or non-confusability of mutant lines. Genetic stability mutations are most often associated or with a substitute for the base in a certain area of \u200b\u200bthe chromosome DNA, or its loss, adding, moving. As a result, there is a change in the genetic code and, accordingly, the change in the physiological biochemical mechanisms of the cell, which leads to the inhibition of growth, the 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 of obtaining stable plants. This method is most effectively used when working on stability with cultures, which multiply vegetatively, since the reproduction of their seeds entails a complex splitting in the offspring due to the high degree of heterozygency.
It seems to be further improving the existing crops grown in the already mastered lands. Hybrids are something that can play a key role in providing food. After all, most squares suitable for agriculture are already employed. At the same time, an increase in the number of water, fertilizers and other chemicals used on them in many places is economically impossible. That is why the exceptional importance acquires the improvement of existing cultures. And hybrids are plants obtained just as a result of such an improvement.
The task consists not only in increasing yield, but also in increasing the content of protein and other nutrients. For a person, the quality of proteins in edibles (and people including) should also be obtained from food from food the necessary quantities of all indispensable (i.e. those that they are not able to synthesize themselves) amino acids. Eight out of 20 amino acids needed by a person come with food. The remaining 12 can be developed by them. However, plants with improved protein composition inevitably require more nitrogen and other biogenes than the initial forms, therefore it is not always possible to be grown on non-fermentation lands, where the need for such cultures is especially great.
Quality includes not only yield, composition and amount of proteins. Varieties are created, more resistant to disease and pests, due to the more attractive in the form or painting of fruits (for example, bright red apples), better maintaining transportation and storage (for example, hybrids of high-explosion tomatoes), as well as possessing other substantial For this culture properties.
Breeders carefully analyze the available genetic diversity. For several decades, thousands of improved lines of essential agricultural plants took out. As a rule, you have to receive and evaluate thousands of hybrids to select those few of them that will really exceed their properties already widely disturbed. For example, in the USA from the 1930s to the 1980s. It rose almost eight times, although the breeders used only a small part of the genetic diversity of this culture. New and new hybrids appear. This makes it possible to more effectively use sowing areas.
The increase in corn productivity has become possible mainly due to the use of hybrid seeds. Inbred lines of this culture (hybrid themselves in origin) were used as parental forms. From seeds obtained as a result of crossing between them, very powerful corn hybrids are developing. Crosable lines are sown with alternating rows, and from plants one of them is manually cut by panicles (male inflorescences). Therefore, all seeds on these copies are hybrid. And they have very useful properties for humans. By careful selection of inbred lines, you can get powerful hybrids. These are plants that will be suitable for growing in any required terrain. Since the signs of hybrid plants are the same, they are easier to clean. And the yield of each of them is much higher than that of uncomfortable instances. In 1935, the hybrids of corn accounted for less than 1% of all this culture grown in the United States, and now actually all. Now obtaining significantly higher yields of this culture is much less laborious than before.
Over the past few decades, a lot of effort was made to increase wheat yields and other grain, especially in the zones of the warm climate. Impressive successes achieved in international selection centers located in subtropics. When new wheat hybrids derived in them, corn and rice began to be grown in Mexico, India and Pakistan, it led to a sharp increase in the productivity of agriculture, which was named by the green revolution.
The fertilizer and irrigation developed during it were used in many developing countries. Each culture to obtain high yields requires optimal gravity conditions. Fertilizers, mechanization and irrigation are the necessary components of the green revolution. Due to the features of the distribution of loans, only relatively rich landowners were able to grow new hybrids of plants (grain). In many regions, the Green Revolution accelerated the concentration of the Earth in the hands of the few most wealthy owners. Such a redistribution of property does not necessarily provide the work or food majority of the population of these regions.
Traditional selection methods can sometimes lead to amazing results. For example, the wheat hybrid (Triticum) and rye (Secale) triticale (Triticosecale scientific name) is becoming increasingly important in many areas and, apparently, is very promising. It was obtained by doubling the chromosome number in a sterile hybrid of wheat and rye in the mid-1950s. J. O'Mara at the university pcs. Iowa with the help of colchicine, substance that prevents the formation of the cellular plate. Triticale combines the high yield of wheat with the unpretentiousness of rye. The hybrid is relatively resistant to linear rust - fungal disease, which is one of the main yield of wheat. Further crossing and selection gave improved triticale lines for specific areas. In the mid-1980s. This culture due to high yields, sustainability climatic factors And the beautiful straw remaining after cleaning, quickly gained popularity in France, the largest producer of grain in the framework of the EEC. The role of triticale in the human diet is growing rapidly.
Intensive crossbar and selection programs lead to a narrowing of the genetic diversity of cultivated plants on all their signs. For quite understandable reasons, it is mainly aimed at increasing the yield, and among the very homogeneous offspring of the instances of the instances of the specimens, resistance to disease is sometimes lost. Within the culture of the plant are becoming more and more monotonous, since certain signs of their signs are expressed stronger than the others; Therefore, crops in general are more vulnerable to pathogens and pests. For example, in 1970, Helminteporiosis, corn mushroom disease caused by the type of Helminthosporium Maydis (in the photo above), destroyed about 15% of the crop of this culture in the United States, making losses of approximately $ 1 billion. These losses are apparently associated with the advent of the new race of the mushroom, very dangerous for some of the main corn lines widely used in obtaining hybrid seeds. In many commercially valuable lines of this plant, cytoplasma has been identical, since the same pestile plants are repeatedly used when obtaining hybrid corn.
To prevent such damage, it is necessary to grow isolated and maintain various lines of essential crops, which, even if the sum of their signs does not represent economic interest, may contain genes beneficial in the course of continuing pests and diseases.
A striking success in increasing genetic diversity by attracting wild forms achieved tomato breeders. Creating a collection of lines of this culture carried out by Charles Rick and his staff at the University of California in Davis made it possible to effectively deal with many of its serious diseases, in particular, caused by imperfect fungi Fusarium and Verticillum, as well as some viruses. The nutritional value of tomatoes was significantly improved. In addition, plant hybrids have become more resistant to salinity and other adverse conditions. This happened mainly due to systematic collection, analysis and use of lines of wild tomatoes for selection.
As you can see, interspecific hybrids are very promising in agriculture. Thanks to them, it is possible to improve the yield and quality of plants. It should be noted that not only in agriculture, but also in animal husbandry is used crossing. As a result, for example, mule appeared (photo is presented above). This is also a hybrid, a mix of donkey with a mare.
Asks Oleg.Oleg asks: "Hello, Elena! Tell me, please, crossing scientists of various types of plants, vegetables and fruits Is not interference in the creation of God and sin? Successful such crossings do not put creationism for the blow? After all, if it turned out to crush various plants, then The time will be able to cross different animals, a cat with a dog, for example. And therefore, there is a possibility that from one simpler living being appeared more complicated and so right before the appearance of a person? ".
Greetings, Oleg!
Schedule scientists mainly carry out intraspecific crossing (hybridization) for the appearance of desirable signs (for a person, of course) in animals, plants and microorganisms, than achieving new or improved breeds, varieties, strains.
Inside the type, the crossing of individuals is relatively easily due to the similarities of their genetic material and anatomical-physiological features. Although this is not always the case, for example, in vivo it is impossible to cross the tiny dog \u200b\u200bof Chihuahua and a huge mastiff.
But on the way of crossing individuals of different types (and even more different types), molecular genetic barriers that prevent the development of full-fledged organisms. And they are stronger than the currency species and childbirth. By virtue of significantly different genomes of parents in hybrids, unbalanced sets of chromosomes, adverse combinations of genes, violated the processes of cell division and formation (genital cells), may occur, the death of the zygotes (fertilized egg) and other hybrids can be partially or completely sterile (fruitless ), with reduced viability, right up to mortality (although in some cases the first generation there is a sharp increase in viability - heterosis), developmental anomalies may appear, in particular, reproductive organs, or so-called chimeric tissues (genetically heterogeneous), etc. Apparently, therefore, the Lord warned his people: "... Your livestock is not cozy with another rock; your fields do not squeeze in two kinds of [seed] ().
In natural conditions, emergency crossing cases are extremely rare.
Examples of artificial remote hybridization are: Mul (horse + donkey), Bester (Beluga + sterlet), Ligr (Lion + Tigritz), TIGRON (Tiger + Lioness), Leopon (Lion + Leopard's female), Plumkot (plum + apricot), Clementine (orange + mandarin) and others. In some cases, scientists can remove negative consequences Remote hybridization, for example, crumpled wheat and rye hybrids (triticale), radish and cabbage (rafanotemic) were obtained.
And now your questions. Is artificial hybridization with interference in God's creation? In a certain sense, yes, if a person creates a variant other than natural, which can be compared, say, using decorative cosmetics women to improve their appearance. Is artificial hybridization to sin? And meat food consumption is a sin? The Lord on the cruel-fartrum, our permits to kill living beings for food. It is also likely to also in our cruelfold, it allows and selection experimentation for the sake of improving the consumer properties of the products you needs. In the same row - and the creation of drugs (laboratory animals are used and killed). No matter how sad, all this is the real reality of society, where the sin reigns and the rules of the "Prince of this world".
Do you put successful crossing under the blow creationism? In no way. On the contrary.
You know that everything is multiplied by "by its own". Bible "Rod" is not a biological type of modern systematics. After all, a rich variety of species appeared after the flood due to the variability of the signs of ground organisms from Noahow Ark and the water inhabitants who survived outside the ark when adapting them to new environmental conditions. It is difficult to turn the biblical "genus", the genetic potential of which is significant and was determined initially during the creation. It may include such modern taxa, as kind of and genus, but probably not higher (under) families. It is possible, for example, that large cats from the modern systematic clans of the cat's family go back to one source "family", and small feline - to one or two others. It is clear that the types and childbirth distinguished from the biblical "kind" include their own degree of depletion and changed (with respect to the initial) genetic material. The combination of these not fully complementary parts (in interspecific and interdic crossings) meets obstacles at the molecular genetic level, and therefore it does not allow the beginning of a full-fledged body, although in rare cases within the biblical "kind" this may turn out.
What does it say about? The fact that no crossings of the "cat with a dog" and "up to person" can not be in principle.
Another moment. Compare 580 thousand nucleotide pairs, 482 genes in the DNA of unicellular mycoplasma and 3.2 billion nucleotide pairs, about 30 thousand genes in human DNA. If you imagine the hypothetical path "from Amoeba to Human", think about where new genetic information came from? Naturally, she is nowhere to ride. We know that information occurs only from a reasonable source. So who is the author of Amoeba and man?
God's blessings!
Growing plants at home is a very common hobby. But most of the amateurs do not give values \u200b\u200bto the rules of plant care. Although it takes this care quite a little time. And the result by storm pays for all the efforts spent. After all, if everything is done correctly, the plants are healthy, grow great and delight your external species. Therefore, every lover of nature engaged in growing plants, you need to know the answers to at least the main questions related to this occupation.
How to cross the plants? Plant crossing is made in order to get a new variety with the features necessary for the breeder. Therefore, the first thing you need to decide what qualities in the new plant are desired. Then the selection of parental plants, each of which has one or more of such dominant qualities. It makes sense to use plants that have grown in different regions - it makes their heredity richer. But still, before proceeding with selection, it should still be familiar with specialized literature, for example, with a description of the work methods I. V. Michurin.
How to save the plant? There are cases when the plant begins for some reason to die. The first sign is usually the painful state of the leaves. Then you need to check in what condition the stem. If he became too soft, fragile or dug, it remains hope that healthy roots. But if they deteriorate, it means that the plant died. In other cases, you can try to save it. To do this, you will have to cut the damaged part. But completely stalks are not cut off, leaving at least a few centimeters above the soil. Then you need to put the plant so that twice the reduced normal of solar time and moderately water it when the soil is completely dry. Such measures will help the plant to fight the disease and after a few months new sprouts will appear.
How to care for houseplants? So that the plants were healthy and look beautiful, you need to follow a few mandatory rules. First, you need to water them correctly. It is impossible to fill a plant, it is better to nourish. Do it need when the earth is dry. Water should be room temperature. Need to remember that tropical plants They also require daily spraying. Another, important condition for the life of plants is lighting. Be sure to find out the lighting of which intensity and duration is required for the plant and provide for it the necessary conditions. Temperature is a third important factor for the life and health of plants. Most of them are suitable room temperature. But some of the coolest regions need a decrease in temperature in winter. This can be secured by putting a flower on a glazed balcony.
Often, non-specific suspicion relate to hybrid plants, without suspecting that many cultures grown by them on their garden sites are the result of perennial works of breeders.
In downtime plants, such as spinach, when growing in one section, one of the varieties need to remove male plants.
Crossing cross-permeable cultures on isolated plots. Much minimizes labor costs: pollination occurs naturally - wind or insects. In addition, on one isolated area it is possible to lay several plants of one variety, thus increasing the number of obtained hybrid seeds. A significant drawback of this method is in impossibility to completely eliminate the falling of foreign pollen. In addition, with a natural crosswise, about half of the plants are fertilized by the pollen of its variety.
In regions with a warm climate, where the growing season is sufficiently long, for plants with rapidly flowing flowers, insulation can be used in time intervals: different combinations of crossing are carried out on the same site. Different flowering dates exclude unplanned overstate.
In breeding practice, in the absence of sufficient space, insulating facilities are used to organize individual sites:
For plants pollinated by insects, with the construction of insulators, it is better to use materials such as a batter or gauze, for wind-painted crops - parchment paper.
The process of hybridization - plant crossing - aimed at obtaining varieties of plants with the winning properties of parental varieties, such as:
For example, if the father's and maternal plant is resistant to different, the obtained hybrid inherits resistance to both diseases.
Hybrid varieties of plants have better resistance, they are less susceptible to temperature differences, humidity, changes in climatic conditions than their non-mentioned fellows.
More information can be found from the video.
