Solanum lycopersicum
Solanum lycopersicum, commonly known as tomato, is a species of herbaceous plant of the genus Solanum of the Solanaceae family. In its wild state, it is native to the Andean zone of Peru; although its use as food in the domesticated variety would have originated in southeastern Mexico two thousand six hundred years ago.
The plant is cultivated throughout the world for the consumption of its fruit, the tomato, both fresh and processed in different ways: sauce, puree, juice, dehydrated, canned, etc.
Taxonomic description
Etymology
- Solanum: Latin word equivalent to Greek στρνχνος (strychnos) to designate the species Solanum nigrum (the "Hierba mora"), already employed by Pliny the Old in his Natural history (21, 177 and 27, 132) and, before, by Aulus Cornelius Celsus in Re Medica (II, 33). It could be related to Latin Sun., "the sun", because the plant would be of some sunny sites.
- lycopersicum: of the Greek λκος lyco = wolf, and περσικός persicum = Persian, in allusion to the "Persian apple", a name that the Europeans gave to the peach that came to Persia from China. The name originated in the myth of the werewolf. According to Germanic legends, witches and magicians used the fruits of the beaut in their potions to become werewolves. When the tomato came to Europe from America, the great resemblance to those fruits when they are green made them popularly called "wolf peach" (wolf peach peach peach). Linnaeus, in the centuryXVIIIHe applied it in his new classification system by adding it esculentum (comestible).
Synonymy
Solanum lycopersicum has the following taxonomic synonyms:
- Lycopersicon cerasiforme Dunal
- Solanum pomiferum Cav.
- Lycopersicon humboldtii (Willd.) Dunal
- Lycopersicon galenii Mill, 1768
- Lycopersicon esculentum Mill, 1768, Nom. cons.
- Lycopersicon solanum Medik., 1783
- Amatula flava Medik., 1787
- Blondie Medik., 1787
- Solanum spurium J.F.Gmel, 1791
- Lycopersicon pomum-amoris Moench, 1794, nom. illeg.
- Solanum luridum Salisb, 1796, nom. illeg.
- Solanum humboldtii Willd, 1804
- Lycopersicon lycopersicum (L.) H.Karst.,1882, Nom. rejec.
Description
It is an annual or perennial herbaceous plant. The stem is erect and cylindrical in the young plant; as it grows, the stem droops and becomes angular, it has hairs on most of its organs and glands that secrete an aromatic green substance, it can measure up to 2.50 m, it branches abundantly and has axillary buds. If at the end of growth all the ramifications exhibit reproductive buds, they are classified as determinate growth and if they end with vegetative buds, they are classified as indeterminate growth.
The leaves are compound, inserted over the various nodes alternately. The blade is divided into seven, nine and up to eleven leaflets. The upper side is green and the underside greyish. In more rustic tomatoes, the size of its leaves is smaller. The arrangement of veins on the leaflets is penninervian.
It presents inflorescences that can be of four types: simple raceme, uniparous, biparous and multiparous top; being able to have up to fifty flowers per cluster. The flower is formed by a short peduncle, the calyx has the sepals welded together, like the corolla with the petals. The androecium has five or more stamens attached to the corolla with the anthers forming a tube. The anthers are poricidal, rather than dehiscent, and therefore require buzz pollination. The gynoecium presents from two to thirty carpels that, when developed, will give rise to the locules or cells of the fruit. The flowers are hermaphrodites. The calyx is composed of five sepals and the corolla of five yellow petals (occasionally six). The stamens come together to form a tube around the gynoecium. The style is shorter or as long as the stamens; position that considerably favors self-pollination.
The fruit is a red, low-casein berry, variable in size, from 3 cm in diameter to 16 cm, with seeds inside a fleshy pericarp developed from an ovary. Its shape can be rounded, flattened or pear-shaped and its surface smooth or grooved. The seed is of different shades in color, from grayish to straw-colored with a flattened oval shape; between 3 and 5 mm in diameter and 2.5 mm in length, and covered with villi and embedded in an abundant mucilaginous mass. The root, which is taper, reaches up to 1.5 m in depth. [citation required]
Atmosphere
It is a plant with a relatively warm climate, for tomatoes, the optimal temperatures according to the life cycle are: night temperatures between 15 and 18 °C, daytime temperatures 24 to 25 °C, with an ideal flowering temperature of 21 °C. The tomato is classified within the heat-tolerant vegetables, temperatures below 8 °C stop its growth. The tomato plant thrives best in high light intensity. The tomato requirement in terms of soil moisture is medium, excess moisture causes the attack of different pathogens, also influences the growth of tissues, transpiration, fertilization of flowers and development of cryptogamic diseases. On the other hand, relative humidity below 60–65% causes desiccation of pollen.
Cytology and genomics
The tomato, like its wild relatives, is a diploid species with twenty-four chromosomes in its somatic cells.
There are international scientific projects trying to understand basic aspects of nightshade genomics. One such project is to determine the DNA sequence for all gene-carrying regions of the tomato genome. To do this, each of the twelve chromosomes of the haploid tomato genome has been assigned to different sequencing centers in different countries of the world. Thus, chromosomes 1 and 10 correspond to the United States, 3 and 11 to China, 2 to Korea, 4 to the United Kingdom, 5 to India, 7 to France, 8 to Japan, 9 to Spain and 12 to Italy. The sequencing of the mitochondrial genome is the responsibility of Argentina and the chloroplast genome will be sequenced by the European Union.
Conservation status
One theory of domestication of the tomato (Lycopersicon esculentum) indicates that such an event took place in Mexico, while another indicates that it was in Peru, but it is not ruled out that such an event occurred in both places The exact origin of the cultivated tomato remains unresolved; however, in Mexico the species continues to diversify in the tropics and subtropics, where it is known as tomatillo (L. esculentum var. cerasiforme). Although the tomatillo is very popular in the states of Tabasco, Chiapas, Veracruz, Oaxaca, Guerrero, Puebla, Michoacán, and Jalisco, little is known about the wild material, in terms of its nutritional potential and postharvest quality characteristics. recognition and agronomic and biological potential of native varieties of wild tomato; however, the use and management of native, local or regional varieties promotes the management and conservation in situ and ex situ of diversity.
History and distribution
Origins of the tomato
The wild plant from which the current domestic tomato arises would have originated in the Andean zone of northern Peru and southern Ecuador. According to genetic studies published in Molecular Biology and Evolution, a wild species called Solanum pimpinellifolium that has small red fruits, no bigger than a blueberry, and is also known as tomatillo or wild tomato, it is the variety that would have given rise to the modern tomato or Solanum lycopersicum var. 78,000 years ago. By natural means it would have reached Mesoamerica, where it would have been domesticated for the first time. More recently, a evolution in four steps: natural migration from Ecuador to Mesoamerica; involuntary human export from Mesoamerica to northern Peru, circa 3,500–5,000 years BCE. from C., where the tomato was a weed along with shipments of corn; hybridization and domestication of the plant with local variants, growing the fruit; and human export to Mesoamerica, where it would have been improved, expanding the size of the fruit. The tomato was introduced to Europe in the 16th century. At first it was cultivated only as an ornamental plant, but since the 17th century it began to be consumed as human food. Currently the tomato is grown in almost all countries in the world.
The Aztecs and other Mesoamerican peoples used the fruit in their cooking. The exact date of domestication is unknown: it is estimated that in five hundred years before Christ it was already being cultivated in southern Mexico and probably other areas of Mesoamerica.
There is archaeological evidence that shows that the green tomato (Physalis ixocarpa), a species that produces an acidic, green-colored fruit that is still consumed in Mexico, was used as food since pre-Hispanic times. This suggests that the tomato was also cultivated and used by the original Mesoamerican peoples since before the arrival of the Spanish. It is possible that after the arrival of the Spanish, the tomato was cultivated and consumed more than the green tomato due to its colorful appearance and its longer life after being harvested.
The Mayans and other peoples of the region used it for their consumption, and it was cultivated in southern Mexico, and probably in other areas around the 16th century. Within the beliefs of the people, those who witnessed the ingestion of tomato seeds were blessed with divinatory powers. The large, lumpy tomato, a mutation of a smoother, smaller fruit, originated and was encouraged in Mesoamerica. Smith indicates that this is the direct ancestor of some modern cultivated tomatoes.
The Spanish distributed the tomato throughout their colonies in the Caribbean after the conquest of the Americas. They also took him to the Philippines and through there he entered the Asian continent.
Your arrival in Europe
The Spanish conquistador Hernán Cortés may have been the first to transfer the small yellow tomato to Europe after he had captured the Aztec city of Tenochtitlán, now Mexico City, in 1521. The first discussion of the tomato in European literature appeared in an herbal written in 1544 by Pietro Andrea Mattioli, an Italian physician and botanist, who suggested that a new type of eggplant had been brought to Italy, which was blood-red or golden in color when ripe and could be divided into segments and is eaten like an aubergine, that is, cooked and seasoned with salt, black pepper and oil. However, it was not until ten years later that the tomatoes were named in print by Mattioli as pomi d'oro, or "golden apple".
According to some references, the first tomatoes to be cultivated in Italy were yellow in color and in 1554 were described by the Italian botanist Piero Andrea Mattioli as pomo d'oro ("apple golden"); hence the name pomodoro. A cookbook with tomato-based recipes was discovered in Naples and published in 1692, although the author apparently obtained his recipes from Spanish sources. In France of the 18th century they were known as pomme d'amour ("apple of love"); today the red ones are more widespread.
According to Smith, the tomato did not begin to be cultivated in Great Britain until 1590. One of the first cultivators was John Gerard, an English herbalist and botanist. Gerard's book entitled Herbs, was published in 1597, and was largely plagiarized from continental sources; it is also one of the oldest tomato references in England. Gerard learned that the tomato was consumed in both Spain and Italy. However, he claimed it was toxic (tomato leaves and stems contain toxic glycoalkaloids, but the fruit is safe). Gerard's views were influential, and the tomato was considered unfit to eat (though not necessarily toxic) for many years in Great Britain and its North American colonies. However, by the 18th century the tomato was widely consumed in Britain, and before the end of that century the Encyclopedia Britannica indicated that the tomato was "of daily use" in soups, broths and dressings. Tomatoes were originally known as "love apples", possibly based on a mistranslation of the Italian name pomo d'oro ("golden apple").
Cultivation
Cultivation Requirement
- Temperature: The optimal development temperature of tomato cultivation ranges between 20 and 30 °C during the day and between 10 and 17 °C during the night. Temperatures above 35 °C have a negative impact on the development of fertilized eggs and thus affect the growth of fruits. On the other hand, temperatures below 12 °C adversely affect plant growth. Temperatures are especially critical during the flowering period, as above 25 °C or below 12 °C fertilization does not occur. During the fructification temperatures affect the development of the fruits, maturing is thriving as temperatures increase. However, above 30 °C (or below 10 °C) the fruits acquire yellowish tonalities.
- Humidity: optimal relative humidity ranges between 60% and 80%. With humidity greater than 80%, the incidence of diseases in the aerial part of the plant can also be determined by the cracking of fruits or difficulties in pollination, since pollen is appealed. At the other end, relative humidity less than 60% makes it difficult to fix pollen grains to stigma, making it difficult to pollinate.
- Brightness: the tomato needs conditions of very good luminosity, otherwise the processes of growth, development, flowering, pollination and ripening of the fruits can be negatively affected.
- Soil: the tomato plant is not very demanding in terms of soils, except in terms of drainage, which has to be excellent, since it does not support the blacking. However, it prefers loose soils of siliceous and clay texture and rich in organic matter. As for pH, soils can be from slightly acidic to slightly alkaline when they are browned. It is the greenhouse species that best tolerates the salinity conditions of both soil and irrigation water. You should avoid planting tomatoes near a walnut (Juglans), since it injects into its mycorriza a toxin called juglona ((5-hydroxy-1,4-naftoquinone), which affects growth, not only of the tomateras, but also other plants (alelopathy). A kettle that grows in a environment contaminated with juglona grows, on average, a third less than a normal tomato.
- Zumbide pollination: the tomato, as well as other solanaceae requires a type of specialized pollination, called zumbido pollination. Bees are very efficient for this process. The domestic bee, however, is not able to perform zumbido pollination. In the case of greenhouse tomatoes, it is necessary to install bee nests that make the pollination. It is also possible to use artificial methods or polynization manuals.
Varieties
Tomato cultivation is currently widespread around the world, with thousands of cultivars that select a wide variety of species. Cultivated tomatoes range in size from the cherry or cherry tomato that is between 1 and 2 cm, to the beefsteak tomatoes that reach more than 10 cm in diameter. The most widely traded variety tends to be between 5 and 6 cm in diameter. Most cultivars produce red berries, but there are also some with yellow, orange, pink, purple, green, or white. You can also find multicolored and striped fruits.
Transgenic varieties
Polygalacturonase is an enzyme responsible for degrading the cell walls during fruit ripening and, therefore, its activity is responsible for the loss of firmness during the postharvest stages and, ultimately, for the relatively brief period of good quality tomato for fresh consumption. The Flavr Savr tomato is a genetically modified organism developed using the so-called antisense RNA technology with the aim of extending the half-life and, consequently, the quality of the tomato. tomato for fresh consumption. In these tomatoes, it has been possible to reduce the expression of the gene for the production of polygalactruronase, and therefore, the activity of this enzyme during ripening, harvesting, and postharvest of the fruits. After the evaluations of risk and compliance with all the necessary requirements, the Food and Drug Administration of the United States approved in 1994 the commercialization of the variety Flavr Savr, the cu al became the first product derived from a transgenic crop to be released for human consumption.
In 1997, the '"Flavr Savr variety was withdrawn from the market, therefore, as of 2017, there are no transgenic tomatoes for sale in any country in the world.
"Long life" tomatoes are often confused with transgenic tomatoes, although this is not the case. "Long life" tomatoes are a product of conventional breeding.
Classification of varieties by their growth habit
Due to the growth habit, which is given by the type of ramifications of the plants, two large groups of varieties can be recognized: those with indeterminate growth and those with determined growth. The first group is characterized by having a dominant vegetative apex, which gives continuous growth to the main stem or axis. They are easily recognized, since they have a flower cluster for every three leaves and a broad radial growth. The plants of this group are the ones that are most used for the production of tomatoes inside the greenhouse. In determinate growth varieties, the shoots always end in an inflorescence, therefore the upper axillary shoot should always be left to lead it as indeterminate. These plants are called "autopoda" and are recognized because they have a flower cluster every two leaves. This last group of varieties, which are also called "shrubs", do not require support during their growth and are the most used to grow outdoors. Dwarf shrubby varieties are a subgroup within determinate varieties characterized by their smaller size and by producing "cherry" or "cherry". They are mainly used for growing in pots, particularly in hanging containers.
Records
The heaviest tomato was a 3.51 kg tomato, cultivar 'Delicious', Gordon Graham farm, Edmond, Oklahoma in 1986. The largest tomato was one of the cultivar 'Sungold' #39; and grew to 19.8m long, grown at Nutriculture Ltd. (UK), Mawdesley, Lancashire, UK, in 2000.[citation needed]
Wild ancestors
The most likely ancestor of the cultivated tomato is the wild cherry tomato (usually identified as Solanum lycopersicum var cerasiforme), which It grows wild in various tropical or subtropical regions around the world, escaped from cultivation or accidentally introduced.
The wild species are distributed throughout the Americas, vegetating in the South American Andes from central Ecuador through Peru and to northern Chile and on the Galapagos Islands, where the endemic species Solanum cheesmaniae and Solanum galapagaense. Solanum lycopersicum, the immediate wild ancestor of the cultivated tomato, is more widely distributed than other wild tomato species, inhabiting Mexico, Central America, Colombia, Bolivia, Venezuela, and other South American countries. This wide distribution, when compared to the other related species, must have been carried out by humans in historical times. Wild tomatoes inhabit a wide range of habitats, from sea level to elevations of more than 3,000 m above sea level, from the arid Pacific coasts to the humid highlands of the Andes Mountains. Numerous valleys, formed by rivers that carry their waters to the Pacific, characterize the western slopes of the Andes. Wild tomato populations grow at different altitudes in these narrow valleys, are geographically isolated from each other, and are adapted to very particular soil conditions and microclimates. This diversity of habitats has contributed to the great variability that can be found among wild tomatoes.