The more diverse the source material used for breeding, the greater the opportunities it provides for the successful creation of varieties and the more effective the selection results will be. But where in nature to look for this diversity?
N.I. Vavilov and his colleagues, as a result of numerous expeditions, studied the diversity and geographical distribution of cultivated plants. The expeditions covered the entire territory of the former Soviet Union and many foreign countries: Iran, Afghanistan, Mediterranean countries, Ethiopia, Central Asia, Japan, North, Central and South America, etc.
During these trips, about 1,600 species of cultivated plants were studied. Thousands of seed samples were brought from the expeditions, which were sown in the nurseries of the All-Union Institute of Plant Growing, located in different geographical areas former USSR. Work on studying the global diversity of cultivated plants continues to this day. These valuable, constantly replenished unique collections serve as material for breeding work.
As a result of studying all this colossal material, N.I. Vavilov established important patterns, showing that cultivated plants do not have the same diversity in all geographical zones.
Different cultures have their own centers of diversity, where the largest number of varieties, varieties, and various hereditary deviations are concentrated. These centers of diversity are also the areas of origin of the varieties of a given crop. Most centers coincide with ancient centers of agriculture. These are mostly not flat, but mountainous areas.
Such centers of diversity N.I. Vavilov first counted 8. In later works, he distinguished 7 main centers.
South Asian tropical center. Tropical India, Indochina, Southern China, islands of Southeast Asia. It is exceptionally rich in cultivated plants (about half of the known species of cultivated plants). Homeland of rice, sugar cane, many fruit and vegetable plants.
East Asian Center. Central and Eastern China, Japan, Taiwan Island, Korea. The homeland of soybeans, several types of millet, and many fruit and vegetable crops. This center is also rich in species of cultivated plants - about 20% of the world's diversity.
South-West Asian Center. Asia Minor, Central Asia, Iran, Afghanistan, North-West India. The homeland of several forms of wheat, rye, many grains, legumes, grapes, and fruits. 14% of the world's cultural flora originated there.
Mediterranean center. The countries located along the banks Mediterranean Sea. This center, where the greatest ancient civilizations were located, produced about 11% of cultivated plant species. These include olives, many forage plants (clover, lentils), many vegetables (cabbage) and forage crops.
Abyssinian center. A small region of the African continent (Ethiopian territory) with a very unique flora of cultivated plants. Obviously, a very ancient center of original agricultural culture. The homeland of grain sorghum, one type of banana, the oilseed chickpea plant, and a number of special forms of wheat and barley.
Central American Center. Southern Mexico. The homeland of corn, cotton, cocoa, a number of pumpkins, and beans.
Andean (South American) center. Includes part of the Andean mountain range along the west coast of South America. The homeland of many tuberous plants, including potatoes, some medicinal plants (cocaine bush, cinchona tree, etc.).
The vast majority of cultivated plants are related in their origin to one or more of the above geographical centers.
The success of breeding work largely depends on the quality of the source material, mainly on its genetic diversity. The more diverse the source material for selection, the more more possibilities it provides for hybridization and selection. Breeders taking advantage of biological, genetic and environmental diversity flora, created a huge number different varieties cultivated plants.
Modern cultivated plants are grown simultaneously in different countries, on different continents. However, each of these plants has its own historical homeland - center of origin . It was there that the wild ancestors of the cultivated plant were or are still located, where its genotype and phenotype were formed.
Doctrine of centers of origin of cultivated plants created by the outstanding Russian scientist N.I. Vavilov.
N.I. Vavilov initially identified 8 centers of origin of cultivated plants with a number of subcenters, but in later works he consolidated them into 7 main primary centers (see Table 4 and Fig. 42).
| Name of the center and number of cultural species that arose here (% of 1000 - the total number studied) | Cultivated plants that arose in this center from ancient cultures |
| 1. South Asian tropical (about 50%) | Sugarcane, cucumber, eggplant, citrus, mulberry, mango, banana, coconut palm, black pepper |
| 2. East Asian (20%) | Soybean, millet, oats, buckwheat, chumiza, radish, peach, tea, actinidia |
| 3. South-West Asian (14%) | Wheat, rye, peas, lentils, flax, hemp, melon, apple, pear, plum, apricot, cherry, grapes, almonds, pomegranate, figs, onions, garlic, carrots, turnips, beets |
| 4. Mediterranean (11%) | Wheat, oats, rye, cabbage, sugar beets, dill, parsley, olive, bay, raspberry, oak, cork, clover, vetch |
| 5. Abyssinian | Sorghum, durum wheat, rye, barley, sesame, cotton, castor bean, coffee, date palm, oil palm |
| 6. Central American | Corn, beans, potatoes, pumpkin, sweet potatoes, peppers, cotton, tobacco, shag, sisal (fibrous agave), avocado, cocoa, nuts, pecans |
| 7. Andean (South American) | Potatoes, corn, barley, amaranth, peanuts, tomato, pumpkin, pineapple, papaya, cassava, hevea, cinchona, feijoa, coca, Brazil nut (bertholletia) |
Rice. 42. The main geographical centers of origin of cultivated plants: I - South Asian tropical; II - East Asian; III - South-West Asian; IV - Mediterranean; V - Abyssinian; VI - Central American; VII - Andean (South American)
Most of the centers coincide with ancient centers of agriculture, and these are predominantly mountainous rather than flat areas. The scientist highlighted primary And secondary centers of origin of cultivated plants. Primary centers are the homelands of cultivated plants and their wild ancestors. Secondary centers are areas where new forms arise not from wild ancestors, but from previous ones cultural forms, concentrated in one geographical location, often far from the primary center.
Not all cultivated plants are cultivated in their places of origin. Migration of peoples, navigation, trade, economic and natural factors have at all times contributed to the numerous movement of plants to other regions of the Earth.
In other habitats, plants changed and gave rise to new forms of cultivated plants. Their diversity is explained by mutations and recombinations that appear in connection with the growth of plants in new conditions.
A study of the origin of cultivated plants led N.I. Vavilov came to the conclusion that the centers of formation of the most important plant crops are largely connected with the centers of human culture and with the centers of diversity of domestic animals. Numerous zoological studies have confirmed this conclusion.
The study of the origin and evolution of cultivated plants is considered one of the essential branches of selection. N.I. Vavilov wrote that all breeding work, starting from the source material, establishing the main areas of origin of species and ending with the creation of new varieties, is, in essence, a new stage in the evolution of plants, and selection itself can be considered as evolution directed by the will of man.
The success of breeding work depends mainly on the genetic diversity of the original group of plants or animals. Meanwhile, the gene pool of existing animal breeds or plant varieties is naturally less diverse compared to the gene pool of the original wild species.
Therefore, when developing new varieties of plants and animal breeds, searching for and identifying useful traits in wild ancestors is very important. In order to study the diversity and geographical distribution of cultivated plants, N.I. Vavilov organized numerous expeditions both within the territory of our country and to many foreign countries. During these expeditions, huge seed material was collected, which was later used for breeding work. N.I. Vavilov identified 7 centers of origin of cultivated plants (Table 4). He made important generalizations that served as a major contribution to the theory of selection.
The study of hereditary variability in cultivated plants and their ancestors allowed N.I. Vavilov to formulate the law of homological series of hereditary variability: “Species and genera that are genetically close are characterized by similar series of hereditary variability with such regularity that, knowing the series of forms within one species, one can predict the presence of parallel forms in other species and genera. The closer the genera and species are genetically located in the general system, the more complete the similarity in the series of their variability. Entire families of plants are generally characterized by a certain cycle of variability passing through all the genera and species that make up the family.”
Table 4. Centers of origin of cultivated plants (according to N.I. Vavilov)
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Using the example of the cereal family N.I.
Vavilov showed that similar mutations are found in a number of species of this family. Thus, black seed color is found in rye, wheat, barley, corn and a number of other plants, with the exception of oats, millet and wheatgrass, and an elongated grain shape is found in all studied species. Similar mutations are also observed in animals: albinism and lack of fur in mammals,
albinism and lack of feathers in birds, short-toed spines in cattle, sheep, dogs, birds. Some hereditary diseases and deformities found in humans are also noted in some animals. Animals with such diseases are used as models to study similar defects in humans. For example, cataracts of the eye occur in mice, rats, dogs, and horses; hemophilia - in mice and cats; diabetes - in a rat; congenital deafness - in guinea pig, mice, dogs, etc. The fact that similar, hereditarily determined disorders of life activity are found in representatives of different species of the same class - the class of mammals - convincingly confirms the law of homological series of hereditary variability N.I. Vavilova. The appearance of similar mutations is explained by the common origin of the genotypes. In the process of the emergence of new species from one common ancestor, differences between them are established only in part of the genes that determine successful existence in given specific conditions. Many genes in species that have a common origin remain unchanged and, when mutated, produce similar properties.
Thus, the discovery of spontaneous or induced mutations in one species provides grounds for searching for similar mutations in related species of plants or animals.
The law of homological series of hereditary variability is successfully used in breeding practice. Work on creating seed collections of varieties of cultivated plants and their wild ancestors, which began with N.I. Vavilov, is currently ongoing. In our country, the collection includes more than 320 thousand specimens belonging to 1041 plant species. This includes wild species, relatives of cultivated plants, old local varieties, all the best and new that has been created in the past. Lately through the efforts of breeders from all over the world. From the world's gene pool, scientists identify genetic sources of economically valuable traits: productivity, early maturity, resistance to diseases and pests, drought resistance, resistance to lodging, etc. Modern genetic methods make it possible to achieve very large successes in plant breeding. Thus, the use of valuable genes of wild Ethiopian barley made it possible to create the spring barley variety Odessky 100, which is outstanding in productivity.
Questions for review and assignments
How do domesticated animals and cultivated plants differ from wild ones?
What is the subject of selection?
What is the importance for selection of knowledge of the centers of related cultivated plants!!
What centers of origin of cultivated plants do you know?
Why do closely related species exhibit similar mutations?
Explain the essence of the law of homological series of hereditary variability N.I. Vavilova.
Plant breeding
Selection is the science of creating new and improving existing breeds of animals, plant varieties, and strains of microorganisms.
Selection is based on methods such as hybridization and selection. Theoretical basis selection is genetics.
Breeds, varieties, strains are artificially created by man populations of organisms with hereditarily fixed characteristics: productivity, morphological, physiological characteristics.
The pioneer in the development of the scientific foundations of breeding work was N.I. Vavilov and his students. N.I. Vavilov believed that selection is based on the correct choice of initial individuals for work, their genetic diversity and influence environment on the manifestation of hereditary characteristics during hybridization of these individuals.
For successful work the breeder needs varietal diversity of the source material; for this purpose, N.I. Vavilov collected a collection of varieties of cultivated plants and their wild ancestors from all over globe. By 1940, the All-Union Institute of Plant Growing had 300 thousand samples.
In search of source material for obtaining new plant hybrids, N.I. Vavilov organized in the 20s and 30s. XX century dozens of expeditions around the world. During these expeditions, N.I. Vavilov and his students collected more than 1,500 species of cultivated plants and a huge number of their varieties. Analyzing collected material, N.I. Vavilov noted that in some areas there is a very large diversity of varieties of certain types of cultivated plants, while in other areas there is no such diversity.
Centers of origin of cultivated plants
N.I. Vavilov suggested that the area of greatest genetic diversity of any type of cultivated plant is the center of its origin and domestication. In total, N.I. Vavilov established 8 centers of ancient agriculture, where people first began to grow wild plant species.
1. The Indian (South Asian) center includes the Hindustan Peninsula, South China, and Southeast Asia. This center is the birthplace of rice, citrus fruits, cucumbers, eggplants, sugar cane and many other types of cultivated plants.
2. The Chinese (East Asian) center includes Central and Eastern China, Korea, and Japan. In this center, millet, soybeans, buckwheat, radishes, cherries, plums, and apple trees were cultivated by humans.
3. The South-West Asian center covers the countries of Asia Minor, Central Asia, Iran, Afghanistan, North-West India. This is the birthplace of soft varieties of wheat, rye, legumes (peas, beans), flax, hemp, garlic, and grapes.
5. The Mediterranean center includes European, African and Asian countries located along the shores of the Mediterranean Sea. This is the homeland of cabbage, olives, parsley, sugar beets, and clover.
6. The Abyssinian center is located in a relatively small area of modern Ethiopia and on the southern coast of the Arabian Peninsula. This center is the birthplace of durum wheat, sorghum, bananas, and coffee. Apparently, of all the centers of ancient agriculture, the Abyssinian center is the most ancient.
7. The Central American center is Mexico, the islands Caribbean Sea and parts of Central America. Here is the birthplace of corn, pumpkin, cotton, tobacco, and red pepper.
8. The South American Center covers the western coast of South America. This is the birthplace of potatoes, pineapple, cinchona, tomatoes, and beans.
All these centers coincide with the places of existence of the great civilizations of antiquity - Ancient Egypt, China, Japan, Ancient Greece, Rome, Mayan and Aztec states.
Centers of origin of cultivated plants
|
Centers of origin |
Location |
Cultivated plants |
|
1. South Asian tropical 2. East Asian 3. South-West Asian 4. Mediterranean 5. Abyssinian 6. Central American 7. South American |
Tropical India, Indochina, Southeast Asian Islands Central and Eastern China, Japan, Korea, Taiwan Asia Minor, Central Asia, Iran, Afghanistan, South-West India Countries along the Mediterranean Sea Abyssinian highlands of africa Southern Mexico West coast of South America |
Rice , sugar cane, citrus fruits, eggplants, etc. (50% of cultivated plants) Soybean, millet, buckwheat, fruit and vegetable crops - plum, cherry, etc. (20% of cultivated plants) Wheat, rye, legumes, flax, hemp, turnips, garlic, grapes, etc. (14% of cultivated plants) Cabbage, sugar beets, olives, clover (11% of cultivated plants) Durum wheat, barley, coffee tree, bananas, sorghum Corn, cocoa, pumpkin, tobacco, cotton Potatoes, tomatoes, pineapple, cinchona. |
9. Basic methods of plant breeding
1. Mass selection for cross-pollinated plants (rye, corn, sunflower). The selection results are unstable due to random cross-pollination.
2. Individual selection for self-pollinating plants (wheat, barley, peas). The offspring from one individual is homozygous and is called a pure line.
3. Inbreeding (inbreeding) is used for self-pollination of cross-pollinated plants (for example, to obtain lines of corn). Inbreeding leads to "depression" as recessive unfavorable genes become homozygous!
Aa x Aa, AA + 2Aa + aa
4. Heterosis (" life force") is a phenomenon in which hybrid individuals are significantly superior in their characteristics to their parent forms (yield increase of up to 30%).
Stages of obtaining heterotic plants
1. Selection of plants that give the maximum effect of heterosis;
2. Preservation of lines through inbreeding;
3. Obtaining seeds as a result of crossing two inbred lines.
Two main hypotheses explain the effect of heterosis:
The dominance hypothesis - heterosis depends on the number of dominant genes in a homozygous or heterozygous state: the more pairs of genes there are dominant genes, the greater the effect of heterosis.
Overdominance hypothesis - a heterozygous state for one or more pairs of genes gives the hybrid superiority over the parental forms (overdominance).
Cross-pollination of self-pollinators is used to obtain new varieties.
Cross-pollination of self-pollinators makes it possible to combine the properties of different varieties.
6. Polyploidy. Polyploids are plants that have an increase in the chromosome number that is a multiple of the haploid one. In plants, polyploids have a greater mass of vegetative organs and larger fruits and seeds.
Natural polyploids are wheat, potatoes, etc.; varieties of polyploid buckwheat and sugar beets have been bred.
The classic way to obtain polyploids is to treat seedlings with colchicine. Colchicine destroys the spindle and the number of chromosomes in the cell doubles.
7. Experimental mutagenesis is based on the discovery of the effects of various radiations to produce mutations and the use of chemical mutagens.
8. Distant hybridization - crossing plants related to different types. But distant hybrids are usually sterile, since their meiosis is disrupted.
In 1924, the Soviet scientist G.D. Karpechenko obtained a fertile intergeneric hybrid. He crossed radish (2n = 18 radish chromosomes) and cabbage (2n = 18 cabbage chromosomes). The hybrid has 2n = 18 chromosomes: 9 rare and 9 cabbage, but it is sterile and does not form seeds.
Using colchicine, G.D. Karpechenko obtained a polyploid containing 36 chromosomes; during meiosis, rare (9 + 9) chromosomes were conjugated with rare, cabbage (9 + 9) with cabbage. Fertility was restored.
In this way, wheat-rye hybrids (triticale), wheat-wheatgrass hybrids, etc. were subsequently obtained.
9. Use of somatic mutations.
By using vegetative propagation it is possible to preserve a beneficial somatic mutation. In addition, only through vegetative propagation are the properties of many varieties of fruit and berry crops preserved.
10 . Technological scheme for obtaining potato concentrate
Simplified technological scheme obtaining potato concentrate, reduced the energy costs and labor intensity of its production by scientists from the Republican Unitary Enterprise "Scientific and Practical Center of the National Academy of Sciences of Belarus for Food" (patent of the Republic of Belarus for invention No. 15570, IPC (2006.01): A23L2/385; authors of the invention: Z. Lovkis, V. Litvyak, T. Tananaiko, D. Khlimankov, A. Pushkar, L. Sergeenko; applicant and patent holder: the above-mentioned RUP). The invention is intended to provide a potato concentrate used in the formulations of non-alcoholic, low-alcohol and alcoholic drinks with improved organoleptic characteristics.
The proposed method for producing potato concentrate includes several stages: preparation of potato raw materials, which use fresh potatoes and (or) benign dry and mashed potato waste; its thermal and subsequent two-stage treatment with amylolytic enzymes; separation of the formed precipitate by filtration; concentration of the filtrate by evaporation; its acidification with one or more organic acids; subsequent temperature control.
After thermostatting, aqueous and (or) aqueous-alcoholic infusions of aromatic plants are added to the resulting concentrate in a certain amount to a final dry matter content of 70±2%. The range of these plants is wide: cumin, purple coneflower, medicinal hyssop, coriander, sweet clover, oregano, immortelle, balsam tansy, peppermint, tarragon wormwood and others.
A huge amount of plant material was collected on four continents of the globe by N. I. Vavilov and his collaborators.
Under his leadership and according to the program he proposed, this material was studied for a long time. Research confirmed N.I. Vavilov’s assumptions about the existence of five independent centers of the formation of cultivated plants - about five centers of their origin. And in 1926, the scientist first published his major work, “Centers of Origin of Cultivated Plants.”
Then, in 1935, after a more detailed and lengthy study of the varietal riches of the globe in laboratories, at experimental sites of VIR and its network, N. I. Vavilov, in his work “Botanical-geographical foundations of selection,” significantly expanded the previous concept of the centers of origin of cultivated plants.
This work sets out the original doctrine of the geographical distribution of varietal plant wealth of the globe as the basis on which practical selection should be based. N.I. Vavilov was the first to try to establish the areas of origin and geographical location of the main potentials (opportunities) of the most important agricultural crops: cereals, industrial, vegetable, fruit and subtropical plants.
The foci of formation, or geographic centers of origin, of cultivated plants were established using a differential botanical-geographical method, which consists of the following:
“In the strict differentiation of the studied plant into Linnaean species and genetic groups using morphological-systematic, hybridological, cytological and immunological analyses.
In establishing the range of these species, if possible, in the former distant time, when communications were more difficult than at the present time.
In the detailed determination of the composition of the botanical varieties and races of each species, or of the general system of hereditary variability within individual species.
In determining the distribution of hereditary diversity of forms of a given species by region and country; in establishing the geographic centers of accumulation of major diversity.”
Differentiation - dismemberment. Genetic groups are related by origin. Morphological-systematic analysis-- study plants, taking into account the forms and structure of plants and their distribution into groups according to similarities and differences. Hybridology is the study of hybrid crosses. Cytology is the science of the structure and vital manifestations of plant cells. Immunological analysis - the attitude of plants to infectious diseases. Habitat - area of distribution.
N.I. Vavilov distinguished secondary foci from the primary main foci of formation. Thus, sometimes the modern accumulation of varietal diversity is the result of the convergence of species or their crossing with each other. For example, an exceptionally large number of wheat species are found in Spain. However, the number of varieties and races within individual species is very small compared to their diversity in the actual centers of formation of these species. The diversity of wheat species in Spain is explained by their attraction from other areas.
The systematic study of the world's plant resources of the most important cultivated plants has radically changed ideas about the varietal and species composition of even such seemingly well-studied crops as wheat, potatoes, corn, legumes, flax and rye. In general, almost half of the new species and many varieties of these cultivated plants have been discovered. The discovery of new species and varieties of potatoes literally revolutionized previous ideas about its original breeding material.
Three quarters of new botanical varieties and half of new species are found in wheat. An exceptional diversity of wheat and barley varietal richness has been discovered in Ethiopia. A very large number of new varieties and crops have been found in Afghanistan, Turkey, and North-West India. A significant number of species of cultivated plants did not go beyond the boundaries of their main primary ancient centers. Tens and hundreds of species of cultivated plants have been cultivated for thousands of years where they were introduced into culture.
In Central and South America, the primary areas of speciation turned out to be “extremely localized” (limited to a specific location). The most interesting areas of primary formation and speciation of wheat, rye and especially fruit plants- Soviet Transcaucasia and adjacent areas of Northwestern Iran and Northeastern Turkey. Here it was still possible to trace the process of speciation of different plants.
Even for such ancient plants as wheat, barley, corn, cotton, which long ago spread across all continents, it was possible to establish with great accuracy the main areas of primary species potential.
The coincidence of areas of primary formation for many species and even genera has been established. In some cases, we can talk about the same habitats for dozens of species. Geographical study has led to the establishment of entire cultural independent floras specific to individual regions.
Summing up the results of the study of plant material collected by expeditions that covered up to 60 countries, as well as the entire Soviet Union, N. I. Vavilov in 1935 already outlined eight main ancient centers of world agriculture, more precisely, eight independent areas of introduction into culture various plants. These foci are as follows.
I. Chinese hearth the origin of cultivated plants is the mountainous Central and Western China with the adjacent lowland areas. This focus is characterized exclusively a large number cultivated plants (temperate, subtropical and partly tropical zones) - 136 diverse crops are representatives of this focus.
The most important endemics of its temperate zone: millet (three species), buckwheat, soybeans, legumes (several species), and oilseeds - suza, tung tree, radish. An exceptionally large number of aquatic plant species specific to China. Many citrus fruits also originate from China.
In general, the cultural flora of China is extremely original and differs sharply from other primary centers of agriculture. In terms of the richness of endemic species and the magnitude of the species and generic potential of cultivated plants, China stands out among other centers.
Potency - possibility; something that exists in a latent form and can manifest itself under certain conditions.
The cultural flora of China is represented by a huge number of botanical varieties: the diversity of soybeans, persimmons, adzuki beans, and citrus fruits is determined by thousands of easily distinguishable forms.
II. Indian hearth origin of cultivated plants (includes the states of Assam and Burma) - the birthplace of rice, sugar cane, a large number of pulses, many tropical fruit plants (mangoes) and many citrus fruits - lemons, oranges, some types of tangerines. The state of Assam stands out for its wealth of citrus fruits.
There are wild varieties of rice here; ordinary rice in the wild and as a weed, as well as intermediate forms between wild and cultivated rice. The variety composition of cultivated rice in India is the richest in the world and is characterized primarily by the presence of dominant traits. In total, 117 different crops were found in this outbreak.
IIa. Indo-Malay hearth origin of cultivated plants - the Malay Archipelago (Java, Sumatra, Borneo), the Philippines and Indochina. This outbreak is located almost entirely in a tropical zone, little explored, exceptionally rich in wild flora, almost unexplored.
A wealth of forms is concentrated here fruit crops- bananas, some citrus fruits; areca and herring palms, coconut palm (as an oil plant); sugar bearers - sugar cane (one of the hotbeds), sugar palm. Spicy ones include cardamom, cloves, nutmeg. There are 55 plants in total.
III. Central Asian outbreak the origin of cultivated plants is Northwestern India (now Pakistan), all of Afghanistan, the Tajik and Uzbek SSR and the Western Tien Shan. This focus in terms of the number of species is significantly inferior to the first two, but for Soviet selection it has very great importance. Here is the homeland of the main bread of the earth - soft wheat, the colossal potential of its varietal diversity, the homeland of dwarf and short-grain wheat, the most important leguminous crops - peas, lentils, chin, chickpeas, faba beans.
Cotton - guza - was also introduced into cultivation here, and many oil-bearing plants originate from here. This is one of the centers of flax, sesame, coriander, safflower, the main center of carrots of Asian forms, a secondary center for melon, one of the centers of pistachio, apricot and almonds with a wide variety of its forms.
There are only 42 plant species, but they are distinguished by exceptional intraspecific diversity, especially in the most important crop - soft and dwarf wheat.
IV. Western Asian focus the origin of cultivated plants is inner Asia Minor, all of Transcaucasia, Persia (now Iran) and Mountainous Turkmenistan (Soviet). This focus is remarkable for its exceptional richness of cultivated wheat species: nine botanical species wheats are endemic to the regions of Western Asia. Within the Soviet Union, in Armenia there are more than 200 varieties of wheat out of a total world number of 650. In Armenia, a large variety of forms of wheat has been discovered - einkorn and einkorn.
Transcaucasia and Asia Minor are the main homeland of rye, which here is represented by a wide variety of forms, in contrast to the exclusively monotonous rye of Europe. New species of wild rye were also found here.
Western Asia is the birthplace of grapes, pears, cherry plums, cherries, pomegranates, walnut, quince, almonds and figs. The first gardens were created here. In Georgia and Armenia, all evolutionary phases of fruit growing can now be observed: from forests consisting of wild fruit trees to modern horticulture.
The entire main range of grape varieties was borrowed by Europeans from Western Asia, where grapes were found in a wild state, quite suitable for cultivation.
The entire world's wealth of melon varieties comes from Turkey, Persia (Iran) and our Central Asia. Many forage grasses: alfalfa, Persian clover (shabdar), some types of sainfoin, fenugreek, common vetch and others originate from Western Asia.
V. Mediterranean focus The origin of cultivated plants includes all countries of the coast and islands of the Mediterranean Sea. In this focus, first of all, one can trace the large role of man in selection various forms plants for culture. Plants cultivated in these countries gradually acquired the most cultivated economic characteristics.
Most of the cultivated plants of this focus - flax, barley, beans, chickpeas - are distinguished by large-grained, large-fruited plants, while in their real homeland (Central Asia) they are represented by small-grained forms.
It is interesting that here each great civilization introduced its own food plant into cultivation: Egypt (now the United Arab Republic) and Syria - Alexandrian clover, on the Apennine Peninsula they introduced sulla and creeping giant clover, on the Iberian Peninsula - single-flowered lentils. The rank came from Syria, and the ulex from Portugal.
Many of the important cultivated plants (wheat, grain legumes) are very diverse here in their varietal and species composition, which indicates a secondary focus of their origin.
Here is the birthplace of olives, carob, a large number of vegetable crops, including beets, sandy oats and other plants. In total, there are 83 plant species in this outbreak.
VI. Abyssinian outbreak origin of cultivated plants - Ethiopia, Eritrea and Somalia.
The number of plants native to Ethiopia is small. As already mentioned, during N.I. Vavilov’s visit to her in 1927, she practically knew neither vegetable nor fruit plants. There was basically a kingdom of field crops with their exceptional varietal diversity.
Despite limited size cultivated area and the relatively uniform ecological conditions of Ethiopia, exceptional varietal richness was discovered there.
The main areas under crops in Ethiopia are concentrated in mountainous areas from 1500 to 2500 meters above sea level.
Ethiopia ranks first in the number of botanical varieties of wheat, and genetic and physiological studies of these wheats have shown that they should be recognized as special botanical species.
Ethiopia is the center of the formation of cultivated barley; in no other place is there such a variety of its forms. Here is the birthplace of the cereal grain - teff, a unique form of flax, cultivated for its seeds, from which flour is obtained.
VII. Southern Mexican and Central American Center origin of cultivated plants (including the Antilles). Main feature This center of formation is the sharp localization of centers of agriculture. This center is limited to the southern regions of Mexico and small areas(mountainous) Guatemala and Honduras, where the main wealth of cultivated plants of the New World is concentrated.
Here is the birthplace of corn, which is as important in the New World as wheat is in the Old World; without it, the Mayan civilization could not have arisen; homeland; the closest relative of corn is the wild species teosinte, the main American types of beans, pumpkins, peppers, and tropical fruit plants. This is where the culture of cocoa, sweet potato, and Mexican tomato came from.
Originate from Southern Mexico the best varieties American cotton - uplands, on which world cotton growing is based.
In limited areas of Southern Mexico and Central America, endemic crops are concentrated, while in vast areas of North America, both in the past and now, agriculture is based on borrowed crops.
VIII. South American (Peruvian-Ecuadorian-Bolivian) center origin of cultivated plants. Here, Soviet expeditions discovered huge and completely untouched accumulations of cultivated plants.
Dozens of new cultural and related ones have been discovered wild species potatoes, which have been used by Indian tribes since ancient times.
The highland regions of Peru, Bolivia and Ecuador preserve original endemics, ranging from potatoes and horse-tuberous plants - oca, anyu, ulyuco, characteristic only of this part of the globe. Among the cereals found here are Bolivian lupine and two types of quinoa (quinoa and cañahua).
In these limited areas, 45 species of various plants have been collected, and the farming culture here is non-irrigated and concentrated in the mountain plains, in the so-called Pune.
VIIIa. Chiloan outbreak- a small area of the island of Chiloe, located off the coast of Southern Chile, is somewhat different from outbreak VIII. From here, for the first time, Europeans borrowed the common potato (Solanum tuberosum L.), characterized by 48 chromosomes. It turned out to be suitable for European conditions and adapts well to long days. Most of the most interesting potato forms for breeding from Peru, Bolivia and Ecuador require short days for normal development and do not form tubers under normal conditions in Europe, where daylight hours are long.
VIIIb. Brazil-Paraguay outbreak. Huge Brazil is filled with the richest wild flora - up to 40,000 species, but has so far given the world a very small number of cultivated plants. Of these, the most important are pineapple, groundnut and cassava. These plants grow in semi-desert dry areas. The rubber tree, whose homeland is the Amazon River valley, remains there in a wild state; it was introduced into culture by the Dutch and English in South Asia.
In the pre-Columbian period, the Indian tribes of North America in the United States cultivated sunflower and Jerusalem artichoke, where they are still found in the wild.
All eight main centers of species and varietal potential of the most important plants on earth are strictly localized, separated by deserts or mountain ranges separating them.
The Chinese hearth is separated from the Central Asian one by a huge desert and mountain semi-deserts Central Asia. The Western Asian focus is separated from the Central Asian by the Bakvi (Afghanistan) and Seistan (Iran) deserts. The Central Asian hearth is separated from India proper by the Thar Desert. The Mediterranean focus is adjacent to deserts to the south and east. Ethiopia is surrounded by "bera". The Atacama Desert adjoins the mountainous regions of Peru and Bolivia to the west. To the north of the Mexican hotspot is a desert highland.
The very geography of these centers has its own characteristics - “the presence of isolators that contributed to the autonomous development of floras and human settlements, and in their interaction independent agricultural cultures arose. For primitive peoples, these deserts were a huge obstacle, separating them from each other for a long time.”
Based on the results of a detailed and long-term study of the varietal wealth collected (about 250,000 samples of seeds and planting material was collected during the life of N. I. Vavilov) by the expeditions of N. I. Vavilov and his employees, as well as obtained in other ways, differential maps of the geographical localization of varieties of wheat, oats, barley, rye, corn, millet, flax, peas, lentils were compiled , beans, beans, chickpeas, chickpeas, potatoes, carrots and other root vegetables, tomatoes. On these maps you can see where the main varietal diversity of the named plants is concentrated.
In the chapter “World centers (centers of origin) of the most important cultivated plants,” N. I. Vavilov lists 640 of the most important cultivated plants of the earth, of which the countries of the Old World account for five-sixths of the total number known in the world. The New World gave humanity about 100 species of plants.
Within the Old World, the bulk of cultivated plants originated in mountainous and tropical Asia - more than 400 plants.
All of the above shows a complex picture of the distribution of varietal potential on the globe, different from the one presented, for example, by the famous botanists Alphonse de Candolle or Laubach about the homeland of wheat.
The study of the world's plant resources made it possible to completely master the source material for breeding work in the Soviet Union and completely re-pose the problem of source material for selection.
In search of new forms of cultivated plants, Nikolai Ivanovich also turned to weeds, which, displacing the main primary crops, gradually turned into cultivated plants, for example, rye, oats, camelina, rape, and several types of South American potatoes.
Thus, to search for new useful traits of oats, a breeder can turn, for example, to the hearths of the ancient spelled culture, since this crop is contaminated with oats and stores a large and original variety of traits of cultivated oats.
When studying the geographical distribution of species and varietal composition in primary foci and the dispersal of plants from these foci, certain patterns were found that facilitate the search for the necessary plant material.
The patterns discovered by N.I. Vavilov indicate that the primary centers of the formation of cultivated plants are distinguished not only by a large number of forms and races, but also by the presence of predominantly dominant traits in plants. As cultivated species spread from the centers of formation to the periphery, recessive traits begin to predominate. In mountain insulators, the most interesting recessive traits from a practical point of view were discovered.
The world's diversity of hulless barley, hulless millet, and large-grain naked oats is concentrated in China. Here, recessive forms of waxy corn, green beans, and asparagus lobia emerged. Peculiar non-league forms of rye, soft and dwarf wheat were found in the Pamirs, in the mountain isolation centers of Badakhshan in Afghanistan and in the Shugnan region of our mountainous Tajikistan; durum non-league wheat - on the island of Cyprus; The plants of the Mediterranean countries are distinguished by large-fruited and large-grained plants. Plants with signs of precocity, drought resistance and many others are located in a certain geographical regularity.
So, in each region of the globe there is a certain set of cultivated plants and their forms with certain morphological, ecological and other characteristics.
As a result of the systematic collection of the world's collections of cultivated plants and their differentiated botanical and geographical study, N. I. Vavilov discovered new world cultivated plants with all its diversity, created a new direction in the science of cultivated plants; developed the doctrine of the source material for Soviet selection and the basis for the introduction of plants for our country.
Introduction - literally translated means introduction (in agriculture- new plants, varieties from other countries), but N.I. Vavilov gives the “introduction of new crops” a more complex concept.
When studying the same material, a differential intraspecific taxonomy of cultivated plants arose, as a result of which the doctrine of N. I. Vavilov “Linnaean species as a system” appeared. All this made it possible to undertake the publication of a large collective work, “Cultural Flora of the USSR.” During Nikolai Ivanovich’s lifetime, seven volumes of these works were published.
“Cultivated flora” covered the species and varietal diversity of all plants around the globe that are of practical importance in the crop production of our country. The very possibility of compiling and publishing such a work on the basis of the enormous world varietal diversity discovered for the first time and studied according to a specific plan shows to what unprecedented height N. I. Vavilov raised the science of cultivated plants in our country.
A large number of facts speak about the practical importance for our country of collecting and studying “world plant resources”. For example, in the twenties of this century, the world potato industry suffered greatly from fungal and viral plant diseases of a single and little-studied cultural species potatoes. However, from the varietal wealth of cultivated and wild potatoes collected by Soviet botanists in South America, forms and races were selected that are distinguished by exceptional cold resistance, resistance to late blight and other diseases. Already during N.I. Vavilov’s lifetime, Soviet botanists identified 18 species of cultivated and wild potatoes.
The invaluable merit of N. I. Vavilov lies precisely in the fact that, attaching importance to the study of potatoes in his homeland - South America, he organized (in 1926-1932) a number of expeditions (S. M. Bukasov, S. V. Yuzepchuk and N.I. Vavilov himself), who collected and discovered many new types of cultivated and wild potatoes. This made it possible to mobilize exceptional source material for its selection. A task that no breeder in Europe or America could dream of solving - the development of cold-resistant, blight-resistant and starchy potato varieties - became solvable not only in the USSR, but in all countries of the world.
In addition, the discovery of new species refuted the traditional idea of the species unity of cultivated potatoes.
Of no less importance for domestic selection is the world collection of wheat from VIR, most of which was collected by N. I. Vavilov himself. Most of the new varieties of winter durum wheat released recently were obtained by hybridization or individual selection from samples from the VIR collection of the Abyssinian group, characterized by early ripening, or the Syrian-Palestinian group (horanicum Vav.), characterized by early ripening, heat requirements, low strong straw and grain shape, close to round (ideal).
Using samples of these groups of wheat, the Tajik Institute of Agriculture developed the Khoranka 46 variety, and the Azerbaijan Institute of Agriculture - three varieties: Khoranka, Ag-Bugda 13 and Shark. Durum wheat of the villosum Jakub. group, brought by N.I. Vavilov from Palestine, served as the basis for a new Ukrainian variety of winter wheat - Kyiv.
Of great interest is also the group of wheats (ewropaea Vav.), collected in North Africa and Southern Europe and differ in ear productivity, grain size and straw strength. Samples of Algerian, Tunisian wheat and others from this group served as good source material for breeders of the Krasnodar Territory, Volga region, and central black earth regions.
No less interesting is the peculiar group of wheats (caspicum Vav.), studied in detail by N.I. Vavilov, wintering in Dagestan and Transcaucasia. From them the Derbent black-eared and Tajik black-eared were bred.
The very valuable groups of soft wheat collected by scientists in Argentina are represented mainly by hybrid forms (obtained mainly by
further hybridization). Wheat plants of these groups are slightly affected by leaf rust and do not lie down or fall off. They also served as the starting material for the creation of many new varieties of soft wheat for different zones of the USSR (Azerbaidzhanskaya 1, Azerbaidzhanskaya 2, Ossetinskaya 3, Yubileynaya Ossetii, Skorospelaya 3, Bezostaya 4 - strong).
Strong wheats contain a higher percentage of protein and have good baking qualities.
Wheats from Afghanistan, Sweden, Germany, England, Poland, Canada, and the USA also served as the source material for the creation of new breeding varieties in the USSR.
All cotton selection was based on materials collected by N.I. Vavilov’s expeditions in Soviet times. The culture of the humid subtropics was built on the assortment brought either by the expeditions of N.I. Vavilov, or by specialists sent by the relevant Soviet organizations according to his plan.
During the last ten years of N.I. Vavilov’s life, VIR annually sent hundreds of thousands of samples of seeds and planting material of various crops to breeding and plant growing stations. This material served to develop many valuable varieties of cultivated plants that are now put into production.
During Nikolai Ivanovich’s lifetime, on the basis of VIR’s world collection, about 350 varieties of grain, industrial, fodder, vegetable, legume and fruit crops were bred, in addition to what VIR’s own breeders produced.
Three quarters of the varieties of cultivated plants that became known to the whole world by the end of N. I. Vavilov’s life were discovered by Soviet botanists.
So, the task of mobilizing the plant capital of the globe, which arose before N. I. Vavilov at the dawn of Soviet power, was basically resolved in ten to twelve years. Back in 1923 in Petrograd, upon returning from his first trip to the United States, where the scientist studied the experience of the Washington Bureau of Plant Industry, he said that the path to renewing the fields of Soviet Russia was the same as that of the Americans, but it had to be taken differently.
And this path has been passed. “The expeditions of the Institute of Plant Growing were guided by a specific plan and a strictly developed theory. They proved that the theory, if correct, does indeed produce amazing results. The expensive expeditions sent by Washington missed what the Soviet expeditions, armed with a strong theory, found,” wrote N.I. Vavilov already at the end of 1933, when the main expeditions he planned were completed.
The effect of the finds of Soviet expeditions to the Central and South America was so great that special expeditions from Washington, Sweden and Germany were sent in their wake. The scale of work in this direction carried out in Germany at that time can be judged by the fact that Professor Baur in the fall of 1932 showed N.I. Vavilov 100,000 seedlings of various forms of potatoes.
Botanists from the Washington Bureau of Plant Industry then realized that they were facing a serious rival, that in the rush to master the resources of the globe, they first of all rushed to the famous botanical gardens and passed by the “Vavilov mountain centers of Asia and Africa” and did not even visit Afghanistan, but Ethiopia remained almost untouched by the research of Dr. Kharlan, who was sent there a second time after the expedition of N.I. Vavilov.
They also understood that the practical significance of the theories of the Soviet scientist was enormous. The point is not even to “guess to identify” the foci (centers) of concentration of varietal riches of cultivated plants, but also to study the cultivated plants themselves. It took N.I. Vavilov ten years to study the racial composition of soft wheat in order to divide this species into 66 characteristics. And only after that he was able to mark on the world map the supposed center of the formation of soft wheat.
What should be the work of a taxonomist, anatomist, geographer, geneticist, physiologist in order to determine the centers of formation of at least the most important cultures? Washington botanists thought it was just a fantasy. And they asked themselves whether they had worked too fussily for thirty years.
What most struck the botanists from the Washington Bureau was that some of Vavilov’s centers of origin of cultivated plants are located in the New World and are located where the cultures of the Mayans, Aztecs, Incas and Chibchas flourished, where Washington botanists did not even look.
When N.I. Vavilov began work on collecting and studying the world’s collections of cultivated plants, he said that Soviet botanists were not on the same path as Washington’s.
He associated this with the fact that the young Soviet state was building its life on socialist principles. And the time will quickly come when our agricultural production, then based on millions of tiny peasant farms, will be reorganized on new socialist principles. And giant efforts will be required from science to quickly solve this problem. In particular, the institutes headed by N.I. Vavilov will have to supply the country with new crops, new varieties, and answer questions regarding the specialization of agriculture.
And it should be noted that N.I. Vavilov, together with his team of employees, were sufficiently prepared for this. Huge varietal riches of the most important crops were provided in advance to Soviet breeding stations as source material for selection.
N.I. Vavilov raised many new problems: the northernization of agriculture, the development of deserts, mountainous and arid regions; the problem of new crops and much more. To solve these problems, knowledge of cultivated plants was required, and introduction material was required.
Thanks to the mastery of world plant capital and a detailed study of the crop production of our country (varietal testing and geographical crops), the team of the Institute of Plant Growing under the leadership of N. I. Vavilov was able to cope with the task of the People's Commissariat of Agriculture of the USSR to compile the work “Crop Growing of the USSR” in accordance with the decision of the XVI Congress of the All-Union Communist Party (Bolsheviks) .
This work of sixty printed sheets with numerous maps was published in an exceptionally short time (December 15, 1932). About 100 specialist scientists took part in its compilation: plant growers, breeders, botanists, climatologists and soil scientists. The book sums up our knowledge of that time about the cultural flora of Soviet fields and provides the first project for the rational placement of crops and varieties over a vast territory Soviet country, in accordance with socialist reconstruction and specialization of agriculture.
Only our Socialist state, for the first time in the world, in a planned manner, on a scientific basis, drew up a project for the rational placement of crops and varieties and practically implemented it. The scientific basis for this project was contained in “Plant Growing of the USSR”.
In conclusion, it is necessary to answer that the fund of varietal diversity of cultivated plants created during N.I. Vavilov’s lifetime at VIR is preserved to this day. It continues to be studied and expanded. Botanists in our country and many foreign, especially socialist, countries, using the theory of N. I. Vavilov, continue to develop the work he began to study the cultural and wild useful flora of the globe.
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