The origin of cultivated fruit trees in the world is far before the birth of primitive agriculture, and the fruits of wild plants have become the main part of human food. The kinds of wild fruits eaten by human beings in the Stone Age are very complicated. But most of them did not develop into cultivated fruit trees later. The emergence of cultivated plants began with the collection of edible fruits and seeds.
Most important fruit trees have been planted as early as prehistoric times. It is difficult to trace the exact process of how they were domesticated from wild to cultivated fruit trees. Because perennial woody plants are difficult to control collectively, their cultivation origin is undoubtedly much later than that of 1 ~ 2-year-old herbs. Therefore, although wild fruits were eaten and utilized by human beings very early, they later became cultivated plants.
The production of cultivated fruit trees comes from the process of collecting wild → managing wild → cultivating and domesticating. The patterns of origin of many fruit trees are similar and can be seen in some remote mountainous areas. Mountain residents in the Caucasus, West Asia and Tianshan Mountains turn woodland into wheat fields. When trees and shrubs are dug away, pears, apples and cherry plums with better quality are kept in place. There is evidence that grapes were first surrounded in people's homes and protected, which made them climb trees and eventually developed into cultivated fruit trees. This can be regarded as the original state of fruit tree cultivation. Due to uneven development, some fruit trees are still in the stage of collecting wild or managing wild, such as coconut in Africa, which is still mostly in semi-wild state. So do many nut fruit trees. Most of the raw materials for wine brewing in Changbai Mountain area of China, cranberry enterprises in Maine of the United States, and even kiwifruit processing industry that attracted attention in China in 1970s came from wild fruit trees.
Archaeological evidence shows that the earliest fruit trees were figs, dates, olives and grapes. The bronze and stone age Palestine (about 3700 ~ 3500 BC) and Mesopotamia (about 4000 BC) have the conclusive evidence of olive and date palm cultivation. Figs were planted in the late Neolithic period and grapes were planted in the early Bronze Age. As a supplement to food production, their fruits began to appear in early ruins. These fruit trees with early cultivation origin all have a common feature, that is, they are easy to reproduce asexually. It is considered that the cultivation origin of pomegranate will not be later than the above varieties. Later, bananas, mangoes and oranges, as well as some plum trees including almonds, were domesticated and cultivated. In fact, due to apomixis and asexual reproduction, a few tropical fruit trees such as citrus and mango should be easier to enter the ranks of cultivated fruit trees. Because plant remains are more difficult to preserve in a warm and humid climate than in a dry environment, citrus, rich and dead fruits and avocados can obtain much less physical evidence than olives, figs, dates and grapes. According to most data, most of the original oranges originated in China, and some people think that they originated in India and Myanmar. Its cultivation origin is not later than 2000 BC. Pomelo, orange and tangerine were first cultivated in China. The related Fructus Aurantii has long been known and used as an important rhizome of citrus.
The genus Prunus seems to be cultivated from seeds. Wild species of peach are abundant in western China, and they have been cultivated since 2000 BC. Diploid peaches and apricots may be self-pollination systems developed in the western environment of China. The almond with high heterozygosity and self-incompatibility began to be cultivated earlier (3000 BC). Although apples and pears have been studied in detail, their cultivation origins are not clear enough. The cultivation origin of stone fruit trees depends on grafting, especially in situ grafting, which gives them sufficient opportunities to naturally cross with wild species. Wild apples and pears are widely distributed in Europe and Asia, so ordinary apples and pears not only have primitive ancestors, but also have other species, so the cultivation origin is more complicated. Oriental pear wild species originated from northern China and eastern Siberia entered the cultivation earlier, mainly Qiuzi pear and Shali pear originated from China.
The cultivation of nut fruit trees originated relatively late. Although many nuts were found in Neolithic and Bronze Age relics, they were really domesticated later. People seem to prefer varieties that can blossom and bear fruit early, such as figs, grapes, pomegranates, almonds and peaches. Bananas and pineapples also have short growth cycles. However, the childhood of seedling trees is relatively long, especially most nuts. Hazelnut is one of the earliest fruit trees in China, but it has not been greatly improved and developed. This is true of all nuts except almonds.
The planting of a few fruit trees originated very late. For example, the cultivation of raspberries and gooseberries originated in Europe in the16th century. The cultivation of pineapple and strawberry originated in Europe in the18th century. Vaccinium and kiwifruit were not planted and produced in the United States and New Zealand until the 20th century. Some fruit trees were domesticated after repeated failures in introducing similar fruit trees from other regions. For example, American grapes and American plums originated in the United States only attracted attention after the failure of introducing European grapes and prunes from Europe, so their cultivation originated late.
Theory of origin center of cultivated plants
At first, people's idea about the origin of cultivated plants was very simple, and they thought that it was all created by God. /kloc-Before the 0/9th century, the origin of most plants was not clear. /kloc-in the second half of the 9th century, Alphonse De Candolle, a Swiss botanist, first mentioned the origin of cultivated plants, and summarized the previous literature in Textual Research on Cultivated Plants (1882), tracing the origin of cultivated plants with various evidences, breaking through the viewpoint that the origin of cultivated plants is unknown, and holding that cultivated plants all have origins, and discussing cultivated plants in the book. Contemporary C.R. Darwin has extensively studied the evolution of animals and plants in all aspects, and concluded that great changes have taken place under the selected conditions. He used extremely rich materials to prove that the living nature has its own history of development, that the evolution of plants is regular, that wild plants are very barren, and that many plants have undergone profound changes due to cultivation. Darwinism broadens people's horizons and provides a theoretical basis for human beings to transform plants. In the book Research on Plant Hybrids (1865), G.J. Mendel thinks that cultivated plants can tell people the essence of heredity and variation most clearly. When the living environment changes, species will change, and species will have the ability to adapt to the new environment, but environmental change is not the only reason for variation. Cultivated plants are members of different hybrid lines. Mendel attributed the development of cultivated plants, like wild plants, to their special conditions of hybridization and selection.
Soviet scholar vavilov (николайивановичвавил) Many economic plants were collected, the survey data were comprehensively analyzed, a series of scientific experiments were made, and papers such as Plant Geographical Basis of Breeding (1935) were published. The theory of origin center of cultivated plants is put forward. This paper points out the origin of more than 600 main cultivated plants, including crops, vegetables, fruit trees and other related plants, and summarizes the geographical distribution law of variety diversity, which has become an important theoretical basis for variety resources work.
The origin center of cultivated plants in the world
There are also gene centers, evolution centers or diversity centers. Vavilov has a clearer understanding of the actual area of original cultivated plants than Bikando. The orientation work was completed, and the sketch of the origin center of cultivated plants in the world was drawn for the first time. He found that the most diverse area of a plant species is its origin center. The origin centers of many different and unrelated taxa are often the same or overlapping, and it is found that the origin centers of cultivated plants in the world are relatively few and large. These centers basically provide all the important crops in the world.
The world origin center of cultivated plants in vavilov has been revised several times, and finally eight centers are put forward, which are divided into eight regions and three sub-regions (Figure 1). They are (1) China Center. The world's largest agricultural birthplace and the origin center of cultivated plants. It covers the mountainous areas in central and western China and the adjacent lowlands. In addition to cereals, buckwheat, soybeans, all kinds of beans and root and tuber crops, there are a large number of cultivated plants. Fruit trees, pears, apples and plums are called the richest. Many citrus fruit trees also originated here. It surpasses other centers in cultivating the great potential of plants and genera. (2) India Center. Excluding Punjab and other provinces in northwest India, but including Myanmar. The importance ranks second among all major universities. It is the hometown of rice, sugar cane, a large number of beans and many tropical fruit trees such as mango and citrus. 465405 India-Malaya Center. Zhina, Malay Peninsula, Java, Kalimantan, Sumatra and Philippine Islands. Produce some important tropical spices. Tropical fruit trees native to this area include bananas and some oranges, coconuts and olives. Southeast Asia, which is rich in tropical plant resources, has not been fully developed. ③ Central Asia Center. For northern India, Afghanistan, Tajikistan and Uzbekistan of the Soviet Union, and the Western Tianshan Mountains. The range is not large, and there are few plant species. In addition to a large number of wheat varieties, it is also the birthplace of some beans and hemp crops, and the origin center of pistachio, apricot, pear, almond, walnut and other fruit trees. ④ Near East Center. That is, West Asia, including the interior of Asia Minor, all of Transcaucasia, Iran and Turkmen highlands. The origin of wheat, rye and important forage grass is also a treasure house of melons. West Asia is also rich in western fruit tree resources, and is the hometown of grapes, pears, western cherries, walnuts, quince, almonds and figs (5) the center of the Mediterranean. Including Syria, Palestine, western and southern Asia Minor, Greece, Italy and northeastern Africa. There are a series of specially cultivated plants. It is famous for producing special crops, such as cabbage, black mustard, lettuce, asparagus, lavender, hops and laurel. It is also the birthplace of sugar beet. The only fruit trees that originated in this center are olives and carob trees. ⑥ Abyssinia Center. Suitable for Ethiopia, Eritrea, Somalia and other plateau mountainous areas. Although the total number of cultivated plants is small, the variety of wheat is amazing, and it is also the birthplace of barley, coffee and safflower. But there are no local fruit trees here. ⑦ Mexico-Central America Center. It also includes the Antilles. It is the hometown of corn, kidney beans, cocoa and sweet potatoes. Upland cotton originated in southern Mexico. Pineapple, avocado, cashew, guava and papaya in tropical fruit trees all originated here. 8 South American Center. Peru, Ecuador and Bolivia. There are a large number of wild plant resources that have hardly been touched by human beings. Potatoes, tobacco, tomatoes and cassava are all native to South America. The original fruit trees were papaya and passion fruit. 465405 Chile Center. Complement the South American Center. There are Chilean strawberries on the fruit tree. There are about 40,000 species of seed plants in central Brazil-Paraguay, mainly including peanuts, clover gum and Madeicha. Fruit trees include pineapples, cashews and cherries.
Figure 1 Basic concept and development of origin theory vavilov's theory on the origin center of cultivated plants can be summarized as follows: ① There are some variations in cultivated plants in some parts of the world. The place where most varieties and types of a species are concentrated is the origin center of this species. Each variety in the center often has a large number of dominant alleles; Recessive genes are distributed in the central edge and isolated area. ② Some cultivated plants originated from several regions, that is, there are several origin centers. Secondary centers can also develop around primary centers, that is, new diversity regions controlled by recessive alleles. The secondary center will develop special types of cultivated plants. After the cultivated plants spread outward from the center, they may accumulate more variations in other places again. It is usually caused by natural and artificial selection after hybridization between two or more species. The birthplace of cultivated plants is its primary center, and the place where variation and accumulation occur is its secondary center. The two can be distinguished according to the number of dominant genes. For example, the primary center of peaches is in China, and the secondary centers are Iranian, Central Asian, Italian, Spanish and American. ③ The origin center of cultivated plants includes the species and varieties of cultivated plants. These centers are all in the mountains. The most important area where cultivated plants begin to develop is between 20 N and 45 N ... they often coincide with the general trend of large mountains. It is often isolated by deserts, oceans or mountains, which also produces independent flora and independent development of people. The interaction between them produces an independent agricultural culture. ④ Most cultivated plants originated in the east of the world, especially in China and India. These two countries provide almost half of the cultivated plants. Followed by West Asia and the Mediterranean. The original factories in Central Europe, Northern Europe and North America are relatively poor. ⑤ Cultivated plants have the geographical distribution law of their variety diversity. For example, from the Himalayas to the Mediterranean, it can be found that the seeds and fruits of crops tend to get bigger and bigger. However, all the plants that grow in Yemen and Arabian mountains have precocious types. For another example, people in different regions have different resistance to diseases. Other biological differences, such as self-pollination, cross-pollination, apomixis and polyploid tendency, are also different. Breeders must consider the plant geographical characteristics of species in order to find the most valuable germplasm resources to use. The discovery of the origin center of cultivated plants is of great use to plant introduction and domestication and genetic breeders to explore original materials.
Later, scholars showed a lot of changes in some crops in the Western Hemisphere, such as cashew nuts, pumpkins and corn, so that the secondary center of diversity was often confused with the primary center. J.R. Harlan believes that the diversity center is mainly due to the role of several extremely active evolutionary forces in these areas. I.H.Burkill pointed out that the weakness of vavilov's theory is that all the evidence is taken from plants without asking the people who cultivated them. Different microclimates are densely populated in mountainous areas, which increases the chances of mutant survival, and the plant species are indeed richer than those in plains. Where useful and useless plants have the same opportunities, it is a place where experienced breeders explore new types, rather than a reliable origin center for cultivated plants. It is easier to cultivate plants at the edge of mountains than in the middle. He emphasized the importance of natural isolation. People improve olives in natural isolation, which is beyond the distribution range of other species in this genus. Jujube also appears outside the edge of inferior jujube. Figs are on the edge of banyan tree distribution. There is only one variety of busy fruit in its origin, and other inferior varieties are concentrated in Malaya. The origin of coconuts is also far from other kinds of coconuts.
The origin centers of vavilov are all in mountainous areas, which makes sense, but it is also worth considering that they have formed the world agriculture. History shows that the earliest agriculture appeared on the river bank. Because of the emergence of agriculture, in addition to cultivating plants, other conditions are needed, and these conditions are not fully available in remote mountainous areas.
Since then, many people have studied vavilov's theory and made some amendments to the cultivation origin of some crops, but the whole system has not changed. According to chromosome analysis, C.D. Darlington divided the origin of cultivated plants into 9 regions and 6 subregions, which were basically the same as those in vavilov except for adding two subregions in Europe and North America. Because some crops were found outside the origin center of vavilov, Rukovski (пмуковскии) put forward the idea of large gene center in 1970, which expanded the concept of origin center and added Australia.
Fig. 2 Origin of fruit trees in major cultivation centers in the world
From 65438 to 0975, A.G.Zeven and Rukovsky's Dictionary of Cultivated Plants and Their Evolution Center summarized the research results of many scholars on the origin of cultivated plants. According to Rukowski's classification, cultivated plants and their related species are classified into *** 167 families and 2297 species respectively. The revised edition of 1982, edited by Wen Qi and J.M.J.de Wet, was renamed Dictionary of Cultivated Plants and Their Evolutionary Regions, which included 2489 species of 173 families, among which South America and Central America increased the most. Although the collected species are far from complete, we can see the general situation of fruit tree germplasm resources originating from major centers. The types of fruit trees in major centers are as follows: ① China-Japan Center. There are red-fleshed apples, Vitex negundo, Hubei Begonia, Xifu Begonia, Trifolium Begonia, Crataegus, Shari Pear, Pak Lei, Qiuzi Pear, Li Du Pear, Pod Pear, Brown Pear, Crataegus, Hubei Crataegus, Papaya, Peach, Mountain Peach, Gansu Peach, Walnut, Plum, Apricot, Ussurimei, Apricot and so on. Pinellia ternata, Elaeagnus Elaeagnus, milk seed, kiwi fruit, Actinidia arguta, kiwi jujube, camellia, black tea blackberry, Wusu blackberry, raspberry, Vitex negundo, Vitex negundo, chestnut, Japanese chestnut, ginkgo, pecan and Juglans mandshurica. (2) zhina-Indonesian Center. There are 8 kinds of citrus such as grapefruit, lemon, lime and lime, 3 kinds of bananas, 5 kinds of breadfruit and pineapple, 8 kinds of coconut, betel nut and mango persimmon, 2 kinds of rambutan, 3 kinds of mango, 3 kinds of durian, 2 kinds of carambola, 4 kinds of olives and olives, and Du Ying, plum tree and lotus plums. ③ Australia Center. There are sand oranges, macadamia nuts, macadamia bananas and so on. (4) Hindustan Center. There are mangoes, pineapples, cinnamon oranges, Indian wampee, mangji persimmon, Indian wood nai, Indian wood pineapple, ebony peach and so on. ⑤ Central Asia Center. There are five kinds of forest apples, Saiwei apples, Central Asian pears, cherry plums, Italian hawthorn, walnuts, pistachios, European grapes, six kinds of almonds, Elaeagnus angustifolia, black mulberries and Bucara strawberries. ⑥ Near East Center. There are 2 kinds of apples, 4 kinds of pears, quince, European hawthorn, European plum, cherry plum, black thorn plum, European sweet cherry, European sour cherry, European grape, pomegranate, fig, almond, European chestnut, European hazelnut, Eurasian dogwood and so on. ⑦ Mediterranean center. There are olives, European grapes, hazelnuts, carob trees and so on. (8) Africa Center. There are six kinds of dates, cherry oranges, African star apples and butter trees. Pet-name ruby Europe-Siberia center. There are four kinds of Siberian apples, namely Liriodendron chinense, Vitex negundo, western pear, strawberry, black cherry, Siberian apricot, prairie cherry, Siberian gooseberry, robust blackcurrant, black raspberry, Xing 'an blackcurrant, raspberry and sorbet. Attend the South American Center. There are cashew nuts, pineapples, papaya, Chilean strawberry, cherry, pomegranate, egg yolk, golden tiger tail, passion fruit 10, Zizyphus jujuba, Zizyphus jujuba, raspberry and pseudo-lover wood. ⑾ Central America and Mexico Center. 7 species of annona, 2 species of pistachio, 3 species of papaya, hickory, carambola, Biru egg yolk, Rosa roxburghii cactus, 2 species of avocado and 4 species of guava. ⑿ North America Center. 2 species of hickory, 2 species of American plum, 6 species of persimmon, black walnut and American plum, 5 species of strawberry and gooseberry, 3 species of blueberry and 7 species of American grape.
The Origin of Cultivated Fruit Trees in China
China has a long history of fruit cultivation. According to the ancient documents such as The Book of Songs, Summer and modern archaeological excavations, the cultivation origins of peach, plum, apricot, plum, pear, chestnut, jujube, hazel and other fruit trees originating in China were at least 3,000 years ago. In addition to the above deciduous fruit trees, there are also records of southern evergreen fruit trees such as citrus and grapefruit in ancient books such as Gong Yu, Shan Hai Jing and Zhuangzi. Except for a few kinds of citrus such as lemon, most of them were domesticated and cultivated in China for more than 3,000 years. Fruit trees such as longan, litchi, olive, loquat and bayberry have a long history of about 3000 years. However, there is still a lack of systematic research on the cultivation origin of various fruit trees originating in China. Vavilov once pointed out that there may be important discoveries on fruit trees in China, Asia Minor and Iran. Now it has attracted the attention of relevant scholars, and the work is gradually being carried out. According to previous studies, fruit trees originating in China can be divided into three origin centers: ① Yellow River basin and northwest and northeast regions. The original fruit trees mainly include: peach, mountain peach, Gansu peach, light walnut, Xinjiang peach, northeast apricot, Siberian apricot, apricot plum, Wusuli plum, dark plum, Pak Lei, Qiuzi pear, Li Du pear, Muli pear, brown pear, Xinjiang pear, apricot leaf pear, Hebei pear, Shaguo pear, kiwi fruit, red-fleshed apple and Xifu begonia. Vitis amurensis, Actinidia arguta, Mulberry, Vaccinium uliginosum, Jujube, Jujube, Hovenia dulcis, Elaeagnus angustifolia, Chestnut, Hazelnut, Juglans mandshurica, Pinus armandii, Akebia trifoliata, etc. ② Yangtze River Basin. Mainly plum, plum, China cherry, plum, pear, pear, Sichuan pear, bean pear, Hubei begonia, wild hawthorn, monkey hawthorn, thorn grape, Chinese kiwi, delicious kiwi, hairy kiwi, broad-leaved kiwi, persimmon, oil persimmon, emperor, hazelnut, torreya grandis, ginkgo, Li Mao, Castanea henryi and so on. ③ Southern region (including southwest, south-central and southeast). There are mainly Yunnan pear, Lijiang Vitex negundo, Cangjiang begonia, Taiwan Province forest, Jianzui forest, Sikkim begonia, Xiaojin begonia, Yunnan hawthorn, Rosa roxburghii (silk reeling flower), Taiwan Province jujube, Taiwan Province kiwifruit, Taiwan Province kiwifruit, citrus citron, bergamot, 46707 lemon, sweet orange and sour.
Some kinds of wild species, such as kiwi fruit, raspberry, black currant, sorbus sorbus, Castanopsis fargesii and so on. Its origin spans two areas, even all over the country, and it is almost everywhere in mountainous areas. There are also some varieties, such as Actinidia arguta and Siraitia grosvenorii, which are wild in the three places.
Research progress on the origin of cultivated fruit trees
Since the emergence of the theory of the origin center of cultivated plants, the research in this field has been enriched. The crop and vegetable germplasm resources found in these centers have been widely used in plant introduction and domestication and variety improvement all over the world. However, the systematic research on plant germplasm resources in the world has just begun. Although the natural resources of some crops such as wheat, barley and beans have been basically proved, the research on fruit trees is not enough, and little is known about the origin and development process of various fruit trees. Since 1950s, the research on the origin center of various cultivated fruit trees, the origin, distribution and evolution of wild related species and cultivated species has been deepened gradually. Mango, pineapple, avocado and other fruit trees have been further studied, some of which go deep into evolutionary geography, such as bananas and coconuts. But the situation is also very different. The ancestors of some fruit trees are only naturally distributed in very limited areas; Another part of fruit trees are distributed in a vast area. For example, the ancestors of peaches were mainly confined to the west of China, while the wild species of Malus and Pyrus were distributed to China from the Balkans in Europe via Caucasus, Turkestan, Altai Mountain and Siberia. The number of possible ancestors of their cultivated species also varies. For example, more than 20 mutually fertile Malus plants originated in Europe and Asia, and about 10 species originated in North America. However, only four kinds of wild peaches can be regarded as their ancestors.
Like other crops, the primary center of fruit trees is of course important, and the secondary center is now considered not to be ignored. For example, Poland introduced peach seeds from the primary center of China peach and the northeast with bad climate. The former all froze to death at -33℃, while the latter survived. The Soviet Union found that Siberian apple varieties were hardy and had short dormancy period. On the contrary, varieties from Caucasus have long dormancy period and poor cold tolerance. Turkish apricots and almonds grown in the central Anatolia Plateau are obviously more hardy than those grown in the western and southwestern coastal areas, and need a higher degree of freezing. All these show that the potential germplasm resources of the secondary center of cultivated fruit trees are as valuable as their primary centers. Therefore, the research task of the origin of cultivated fruit trees is still very arduous. At present, the development is also uneven. About Europe, southwest Asia and Egypt, we can see a general outline; Archaeological discoveries in Central Asia, Indian subcontinent and East Asia are still insufficient. China's research in this field began to attract attention. The citrus, litchi, loquat and other fruit trees originating in China were preliminarily explored. Although the cultivation origin of some fruit trees is controversial in many aspects, their true images can be investigated by means of archaeology, ancient literature, linguistics, morphology, cytology and genetics. The development of palynology, isozyme analysis and karyotype analysis at the end of the 20th century provided more conditions for research.
cultivated variety
Crop groups with certain economic value selected according to human needs. It is a cultivated plant group and can be clearly distinguished by some morphological, physiological, cytological or other characteristics. Generally speaking, they can keep their characteristics after sexual or asexual reproduction. Fruit tree varieties are agricultural means of production created by human beings to meet different needs. Cultivars of fruit trees must have the following basic characteristics: ① Genetic traits among individuals within the same variety are relatively stable, such as botanical characteristics, biological characteristics, fruit traits, etc. ② It has certain economic value, and the output, quality or other aspects meet the requirements of human beings. ③ It can adapt to certain natural conditions and cultivation conditions, and under suitable conditions, it can give full play to the inherent characteristics and values of this group. Varieties of fruit trees usually refer to the aboveground parts of fruit trees, that is, scion varieties. The rootstock of underground part of fruit trees generally adopts wild species or semi-wild species, which is only called type. For most clonal fruit trees, the same variety actually originated from a single seedling or a clonal population with a changed bud, and the phenotypes of individuals within the variety are highly consistent, which is called clonal variety. Some fruit trees propagated by seeds have similar main characters, but their genotypes are different from their original parents, so they are a mixed population and belong to sexual varieties. Cultivated varieties of fruit trees can be divided into local varieties and bred varieties according to their sources. Local varieties, also known as farm varieties, are formed by artificial and natural selection in long-term fruit tree production. Therefore, they have strong adaptability to local natural conditions and strong resistance to adverse environment, and are often good germplasm resources for breeding. Variety refers to a new variety created through various breeding methods and strict cultivation, identification and selection. Because of the clear breeding objectives, these varieties have many excellent characters. A new variety bred by artificial hybridization is called hybrid variety. Although the varieties formed by natural hybridization in natural environment are also hybrid varieties, their parents are often unknown, so they are called natural hybrid varieties or accidental seedlings. Varieties developed from the selection of fruit tree buds are called bud varieties.
Cultivated varieties are different from botanical varieties. According to international code of botanical nomenclature, varieties are all Latin, while cultivated varieties are generally named in modern languages with capital letters. According to the resolution of 1955, the naming of cultivated plants is divided into three levels, namely, generic name, species name and cultivated variety name. Add the abbreviation of cv before the name of the cultivated variety. (variety) or use single quotation marks. Such as citrus. Valencia, or "Valencia".
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