tomato

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Tomato
Cross-section and full view of a ripe tomato
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
Order:	Solanales
Family:	Solanaceae
Genus:	Solanum
Species:	S. lycopersicum
Binomial name
Solanum lycopersicum L.
Synonyms
Lycopersicon lycopersicum Lycopersicon esculentum

The tomato (Solanum lycopersicum, syn. Lycopersicon lycopersicum & Lycopersicon esculentum^[1]) is a herbaceous, usually sprawling plant in the Solanaceae or nightshade family that is typically cultivated for the purpose of harvesting its fruit for human consumption. Savory in flavor (and accordingly termed a vegetable; see section Fruit or vegetable below), the fruit of most varieties ripens to a distinctive red color. Tomato plants typically reach to 1–3 metres (3–10 ft) in height, and have a weak, woody stem that often vines over other plants. The leaves are 10–25 centimetres (4–10 in) long, odd pinnate, with 5–9 leaflets on petioles,^[2] each leaflet up to 8 centimetres (3 in) long, with a serrated margin; both the stem and leaves are densely glandular-hairy. The flowers are 1–2 centimetres (0.4–0.8 in) across, yellow, with five pointed lobes on the corolla; they are borne in a cyme of 3–12 together. It is a perennial, often grown outdoors in temperate climates as an annual.

The tomato is native to South America. Genetic evidence shows that the progenitors of tomatoes were herbaceous green plants with small green fruit with a center of diversity in the highlands of Peru.^[3] These early Solanums diversified into the dozen or so species of tomato recognized today. One species, Solanum lycopersicum, was transported to Mexico where it was grown and consumed by prehistoric humans. The exact date of domestication is not known. Evidence supports the theory that the first domesticated tomato was a little yellow fruit, ancestor of L. cerasiforme,^{[citation needed]} grown by the Aztecs of Central Mexico who called it xitomatl (pronounced [ʃiːˈtomatɬ]), meaning plump thing with a navel, and later called tomatl by other Mesoamerican peoples. Aztec writings mention tomatoes were prepared with peppers, corn and salt, likely to be the original salsa recipe.

Many historians^[who?] believe that the Spanish explorer Cortez may have been the first to transfer the small yellow tomato to Europe after he captured the Aztec city of Tenochtítlan, now Mexico City in 1521. Yet others^[who?] believe Christopher Columbus, an Italian working for the Spanish monarchy, was the first European to take back the tomato, earlier in 1493. The earliest discussion of the tomato in European literature appeared in a herbal written in 1544 by Pietro Andrea Mattioli, an Italian physician and botanist, who named it pomo d’oro, golden apple.

The word tomato comes from a word in the Nahuatl language, tomatl. French botanist Joseph Pitton de Tournefort provided the Latin botanical name, Lycopersicon esculentum, to the tomato. The Latin name translates to "wolfpeach" - peach because it was round and wolf because it was mistakenly considered to be toxic due to its botanical connection to the Solanaceae or nightshade family.

Aztecs and other peoples in the region used the fruit in their cooking; it was being cultivated in southern Mexico and probably other areas by 500BC. It is thought that the Pueblo people believed that those who witnessed the ingestion of tomato seeds were blessed with powers of divination.^[4] The large, lumpy tomato, a mutation from a smoother, smaller vegetable , originated and was encouraged in Mesoamerica. Smith states this variant is the direct ancestor of some modern cultivated tomatoes.^[5]

According to Andrew F Smith's The Tomato in America,^[5] the tomato probably originated in the highlands of the west coast of South America. However, Smith notes there is no evidence the tomato was cultivated or even eaten in Peru before the Spanish arrived.

Two modern tomato cultivar groups, one represented by the Matt's Wild Cherry tomato, the other by currant tomatoes, originate by recent domestication of the wild tomato plants apparently native to eastern Mexico^{[citation needed]}.

Spanish distribution

After the Spanish colonization of the Americas, the Spanish distributed the tomato throughout their colonies in the Caribbean. They also took it to the Philippines, whence it moved to southeast Asia and then the entire Asian continent. The Spanish also brought the tomato to Europe. It grew easily in Mediterranean climates, and cultivation began in the 1540s. It was probably eaten shortly after it was introduced, and was certainly being used as food by the early 1600s in Spain. The earliest discovered cookbook with tomato recipes was published in Naples in 1692, though the author had apparently obtained these recipes from Spanish sources. However, in certain areas of Italy, such as Florence, the fruit was used solely as tabletop decoration before it was incorporated into the local cuisine in the late 17th or early 18th century.

In Britain

Tomatoes were not grown in England until the 1590s, according to Smith. One of the earliest cultivators was John Gerard, a barber-surgeon.^[6] Gerard's Herbal, published in 1597 and largely plagiarized from continental sources^{[citation needed]}, is also one of the earliest discussions of the tomato in England. Gerard knew that the tomato was eaten in Spain and Italy.^[6] Nonetheless, he believed that it was poisonous^[6] (tomato leaves and stems actually contain poisonous glycoalkaloids, but the fruit is safe). Gerard's views were influential, and the tomato was considered unfit for eating (though not necessarily poisonous) for many years in Britain and its North American colonies.^[6]

But by the mid-1700s, tomatoes were widely eaten in Britain; and before the end of that century, the Encyclopædia Britannica stated that the tomato was "in daily use" in soups, broths, and as a garnish. In Victorian times, cultivation reached an industrial scale in glasshouses, most famously in Worthing. Pressure for housing land in the 1930s to 1960s saw the industry move west to Littlehampton, and to the market gardens south of Chichester. Over the past 15 years, the British tomato industry has declined as more competitive imports from Spain and the Netherlands have reached the supermarkets.

Middle East

The tomato was introduced to cultivation in the Middle East by John Barker, British consul in Aleppo c. 1799 – c. 1825^[7][8] Nineteenth century descriptions of its consumption are uniformly as an ingredient in a cooked dish. In 1881 it is described as only eaten in the region, “within the last forty years.”^[9]

The tomato entered Iran through two separate routes^{[citation needed]}. One route was through Turkey and Armenia and the second route was through the Qajar royal family's frequent travels to France. The early name used for tomato in Iran was "Armani Badenjan" (Armenian Eggplant). The Spanish tomato dish, Paella, is called "Istanbuli Polao" (Istanbul Pilaf) by Iranians. Currently, the name used for tomato in Iran is "Gojeh Farangi" (Foreign Plum).

North America

The earliest reference to tomatoes being grown in British North America is from 1710, when herbalist William Salmon reported seeing them in what is today South Carolina. They may have been introduced from the Caribbean. By the mid-18th century, they were cultivated on some Carolina plantations, and probably in other parts of the Southeast as well. It is possible that some people continued to think tomatoes were poisonous at this time; and in general, they were grown more as ornamental plants than as food. Thomas Jefferson, who ate tomatoes in Paris, sent some seeds back to America.

Because of their longer growing season for this heat-loving crop, several states in the US Sun Belt became major tomato-producers, particularly Florida and California. In California tomatoes are grown under irrigation for both the fresh fruit market and for canning and processing. The University of California, Davis (UC Davis) became a major center for research on the tomato. The C.M. Rick Tomato Genetics Resource Center at UC Davis is a genebank of wild relatives, monogenic mutants and miscellaneous genetic stocks of tomato.^[10] The Center is named for the late Dr. Charles M. Rick, a pioneer in tomato genetics research.^[11] Research on processing tomatoes is also conducted by the California Tomato Research Institute in Escalon, California.

Production trends

About 125 million tons of tomatoes were produced in the world in 2008. China, the largest producer, accounted for about one quarter of the global output, followed by United States and Turkey. For one variety, known as plum or processing tomatoes, California accounts for 90% of U.S. production and 35% of world production.^[12]

According to FAOSTAT, the top producers of tomatoes (in tonnes) in 2007 were:

Top Tomato Producers — 2007 (in tonnes)
China	33 645 000
United States	11 500 000
Turkey	9 919 673
India	8 585 800
Egypt	7 550 000
World Total	126 246 708
Source: UN Food & Agriculture Organisation (FAO)[13]

Cultivation and uses

A basket of tomatoes displayed in a Singapore supermarket.

The tomato is now grown worldwide for its edible fruits, with thousands of cultivars having been selected with varying fruit types, and for optimum growth in differing growing conditions. Cultivated tomatoes vary in size from tomberries, about 5mm in diameter, through cherry tomatoes, about the same 1–2 centimetres (0.4–0.8 in) size as the wild tomato, up to "beefsteak" tomatoes 10 centimetres (4 in) or more in diameter. The most widely grown commercial tomatoes tend to be in the 5–6 centimetres (2.0–2.4 in) diameter range. Most cultivars produce red fruit; but a number of cultivars with yellow, orange, pink, purple, green, black, or white fruit are also available. Multicolored and striped fruit can also be quite striking. Tomatoes grown for canning and sauces are often elongated, 7–9 centimetres (3–4 in) long and 4–5 centimetres (1.6–2.0 in) diameter; they are known as plum tomatoes, and have a lower water content. Roma-type tomatoes are important cultivars in the Sacramento Valley where a 120-acre Morning Star cannery handles 1.2 million pounds^[14] of tomatoes an hour during the harvest season where the fields yield about 40 tons to the acre.^[15]

Tomatoes are one of the most common garden fruits in the United States and, along with zucchini, have a reputation for outproducing the needs of the grower.

As in most sectors of agriculture, there is increasing demand in developed countries for organic tomatoes, as well as heirloom tomatoes, to make up for flavor and texture faults in commercial tomatoes.^[16] Quite a few seed merchants and banks provide a large selection of heirloom seeds. Tomato seeds are occasionally organically produced as well, but only a small percentage of organic crop area is grown with organic seed^{[citation needed]}. The definition of an heirloom tomato is vague, but unlike commercial hybrids, all are self-pollinators who have bred true for 40 years or more.^[17]

Varieties

See List of tomato cultivars

There are many (around 7500) tomato varieties grown for various purposes. Heirloom tomatoes are becoming increasingly popular, particularly among home gardeners and organic producers, since they tend to produce more interesting and flavorful^{[citation needed]} crops at the cost of disease resistance,^[18] and productivity.^[19] Hybrid plants remain common, since they tend to be heavier producers and sometimes combine unusual characteristics of heirloom tomatoes with the ruggedness of conventional commercial tomatoes.

A variety of heirloom tomatoes

Tomato varieties are roughly divided into several categories, based mostly on shape and size. "Slicing" or "globe" tomatoes are the usual tomatoes of commerce; beefsteak are large tomatoes often used for sandwiches and similar applications - their kidney-bean shape makes commercial use impractical along with a thinner skin and being not bred for a long shelf life; globe tomatoes are of the category of canners used for a wide variety of processing and fresh eating; oxheart tomatoes can range in size up to beefsteaks, and are shaped like large strawberries; plum tomatoes, or paste tomatoes (including pear tomatoes), are bred with a higher solid content for use in tomato sauce and paste and are usually oblong; pear tomatoes are obviously pear shaped and based upon the San Marzano types for a richer gourmet paste; cherry tomatoes are small and round, often sweet tomatoes generally eaten whole in salads; and grape tomatoes which are a more recent introduction are smaller and oblong used in salads; campari tomatoes are also sweet and noted for their juiciness, low acidity, and lack of mealiness; they are bigger then cherry tomatoes, but are smaller than plum tomato.

Early tomatoes and cool-summer tomatoes bear fruit even where nights are cool, which usually discourages fruit set.^[20] There are also varieties high in beta carotenes and vitamin A, hollow tomatoes and tomatoes which keep for months in storage.^[21]

Tomatoes are also commonly classified as determinate or indeterminate. Determinate, or bush, types bear a full crop all at once and top off at a specific height; they are often good choices for container growing. Determinate types are preferred by commercial growers who wish to harvest a whole field at one time, or home growers interested in canning. Indeterminate varieties develop into vines that never top off and continue producing until killed by frost. They are preferred by home growers and local-market farmers who want ripe fruit throughout the season. As an intermediate form, there are plants sometimes known as "vigorous determinate" or "semi-determinate"; these top off like determinates but produce a second crop after the initial crop. The majority of heirloom tomatoes are indeterminate, although some determinate heirlooms exist.

A variety of specific cultivars, including Brandywine (biggest red), Black Krim (lower left corner), Green Zebra (top right), et cetera.

Most modern tomato cultivars are smooth surfaced, but some older tomato cultivars and most modern beefsteaks often show pronounced ribbing, a feature that may have been common to virtually all pre-Columbian cultivars. While virtually all commercial tomato varieties are red, some tomato cultivars - especially heirlooms - produce fruit in colors other than red, including yellow, orange, pink, black, brown, ivory, white, and purple, though such fruit is not widely available in grocery stores, nor are their seedlings available in typical nurseries, but must be bought as seed, often via mail-order. Less common variations include fruit with stripes (Green Zebra), fuzzy skin on the fruit (Fuzzy Peach, Red Boar), multiple colors (Hillbilly, Burracker's Favorite, Lucky Cross), etc.

There is also a considerable gap between commercial and home-gardener cultivars; home cultivars are often bred for flavor to the exclusion of all other qualities, while commercial cultivars are bred for such factors as consistent size and shape, disease and pest resistance, and suitability for mechanized picking and shipping, as well as their ability to be picked before fully ripening. The most commonly home grown tomato is the Beefsteak variety.^{[22][not in citation given]}

Tomatoes grow well with 7 hours of sunlight a day. A fertilizer with the ratio 5-10-10, often sold as tomato fertilizer or vegetable fertilizer can be used for extra growth and production, but manure or compost work well, too.

Diseases and pests

Tomato cultivars vary widely in their resistance to disease. Modern hybrids focus on improving disease resistance over the heirloom plants. One common tomato disease is tobacco mosaic virus, and for this reason smoking or use of tobacco products are discouraged around tomatoes, although there is some scientific debate^{[citation needed]} over whether the virus could possibly survive being burned and converted into smoke.^[23] Various forms of mildew and blight are also common tomato afflictions, which is why tomato cultivars are often marked with a combination of letters which refer to specific disease resistance. The most common letters are: V - verticillium wilt, F - fusarium wilt strain I, FF - fusarium wilt strain I & II, N - nematodes, T - tobacco mosaic virus, and A - alternaria.

Tomato fruitworm eating unripe tomato

Another particularly dreaded disease is curly top, carried by the beet leafhopper, which interrupts the lifecycle, ruining a nightshade plant as a crop. As the name implies, it has the symptom of making the top leaves of the plant wrinkle up and grow abnormally.

Some common tomato pests are stink bugs, cutworms, tomato hornworms and tobacco hornworms, aphids, cabbage loopers, whiteflies, tomato fruitworms, flea beetles, red spider mite, slugs,^[24] and Colorado potato beetles.

Pollination

The flower and leaves are visible in this photo of a tomato plant.

In the wild, original state, tomatoes required cross-pollination; they were much more self-incompatible than domestic cultivars. As a floral device to reduce selfing, the pistils of wild tomatoes extended farther out of the flower than today's cultivars. The stamens were, and remain, entirely within the closed corolla.

As tomatoes were moved from their native areas, their traditional pollinators, (probably a species of halictid bee) did not move with them. The trait of self-fertility (or self-pollenizing) became an advantage and domestic cultivars of tomato have been selected to maximize this trait.

This is not the same as self-pollination, despite the common claim that tomatoes do so. That tomatoes pollinate themselves poorly without outside aid is clearly shown in greenhouse situations where pollination must be aided by artificial wind, vibration of the plants (one brand of vibrator is a wand called an "electric bee" that is used manually), or more often today, by cultured bumblebees.

The anther of a tomato flower is shaped like a hollow tube, with the pollen produced within the structure rather than on the surface, as with most species. The pollen moves through pores in the anther, but very little pollen is shed without some kind of outside motion.

The best source of outside motion is a sonicating bee such as a bumblebee or the original wild halictid pollinator. In an outside setting, wind or biological agents provide sufficient motion to produce commercially viable crops.

Hydroponic and greenhouse cultivation

Tomatoes are often grown in greenhouses in cooler climates, and there are cultivars such as the British 'Moneymaker' and a number of cultivars grown in Siberia that are specifically bred for indoor growing. In more temperate climates, it is not uncommon to start seeds in greenhouses during the late winter for future transplant.

Hydroponic tomatoes are also available, and the technique is often used in hostile growing environments as well as high-density plantings.

Picking and ripening

Unripe tomatoes

Tomatoes are often picked unripe (and thus colored green) and ripened in storage with ethylene. Unripe tomatoes are firm. As they ripen they soften until reaching the ripe state where they are red or orange in color and slightly soft to the touch. Ethylene is a hydrocarbon gas produced by many fruits that acts as the molecular cue to begin the ripening process. Tomatoes ripened in this way tend to keep longer but have poorer flavor and a mealier, starchier texture than tomatoes ripened on the plant. They may be recognized by their color, which is more pink or orange than the other ripe tomatoes' deep red, depending on variety.

A machine-harvestable variety of tomato (the "square tomato") was developed in the 1950s by University of California, Davis's Gordie C. Hanna, which in combination with the development of a suitable harvester revolutionized the tomato-growing industry. In 1994 Calgene introduced a genetically modified tomato called the 'FlavrSavr' which could be vine ripened without compromising shelf life. However, the product was not commercially successful (see main article for details) and was only sold until 1997.

Recently, stores have begun selling "tomatoes on the vine", which are determinate varieties that are ripened or harvested with the fruits still connected to a piece of vine. These tend to have more flavor than artificially ripened tomatoes (at a price premium), but still may not be the equal of local garden produce.

Slow-ripening cultivars of tomato have been developed by crossing a non-ripening cultivar with ordinary tomato cultivars. Cultivars were selected whose fruits have a long shelf life and at least reasonable flavor.

Modern uses and nutrition

Tomatoes are now eaten freely throughout the world, and their consumption is believed to benefit the heart among other things. They contain lycopene, one of the most powerful natural antioxidants. In some studies lycopene, especially in cooked tomatoes, has been found to help prevent prostate cancer^[25] but other research contradicts this claim.^[26] Lycopene has also been shown to improve the skin's ability to protect against harmful UV rays.^[27] Natural genetic variation in tomatoes and their wild relatives has given a genetic treasure trove of genes that produce lycopene, carotene, anthocyanin, and other antioxidants. Tomato varieties are available with double the normal vitamin C (Doublerich), 40 times normal vitamin A (97L97), high levels of anthocyanin (P20 Blue), and two to four times the normal amount of lycopene (numerous available cultivars with the high crimson gene).

Tomato consumption has been associated with decreased risk of breast cancer^[28], head and neck cancers^[29] and might be strongly protective against neurodegenerative diseases^[30][31][32].

Though it is botanically a berry, a subset of fruit, the tomato is nutritionally categorized as a vegetable (see below). Since "vegetable" is not a botanical term, there is no contradiction in a plant part being a fruit botanically while still being considered a vegetable.

Tomatoes are used extensively in Mediterranean cuisine, especially Italian and Middle Eastern cuisines. The tomato is acidic; this acidity makes tomatoes especially easy to preserve in home canning whole, in pieces, as tomato sauce, or paste. Tomato juice is often canned and sold as a beverage; Unripe green tomatoes can also be breaded and fried, used to make salsa, or pickled. The fruit is also preserved by drying, often by sun, and sold either in bags or in jars in oil.

Cultural impact

The town of Buñol, Spain, annually celebrates La Tomatina, a festival centered on an enormous tomato fight. Tomatoes are also a popular "non-lethal" throwing weapon in mass protests; and there was a common tradition of throwing rotten tomatoes at bad performers on a stage during the 19th century; today it is usually referenced as a mere metaphor (see Rotten Tomatoes). Embracing it for this protest connotation, the Dutch Socialist party adopted the tomato as their logo.

Known for its tomato growth and production, the Mexican state of Sinaloa takes the tomato as its symbol.^[33]

In October 1965, Reynoldsburg Ohio City Council dedicated a plaque commemorating a proclamation from the Franklin County Historical Society that named Reynoldsburg as the birthplace of the commercial tomato

Storage

Most tomatoes today are picked before fully ripened. They are bred to continue ripening, but the enzyme^{[clarification needed]} that ripens tomatoes stops working when it reaches temperatures below 12.5 °C (54.5 °F). Once an unripe tomato drops below that temperature, it will not continue to ripen.^{[citation needed]} Once fully ripe, tomatoes can be stored in the refrigerator but are best kept at room temperature. Tomatoes stored in the refrigerator tend to lose flavor but will still be edible;^[34] thus the "Never Refrigerate" stickers sometimes placed on tomatoes in supermarkets.

Botanical description

Tomato plants are vines, initially decumbent, typically growing six feet or more above the ground if supported, although erect bush varieties have been bred, generally three feet tall or shorter. Indeterminate types are "tender" perennials, dying annually in temperate climates (they are originally native to tropical highlands), although they can live up to three years in a greenhouse in some cases. Determinate types are annual in all climates.

Tomato plants are dicots, and grow as a series of branching stems, with a terminal bud at the tip that does the actual growing. When that tip eventually stops growing, whether because of pruning or flowering, lateral buds take over and grow into other, fully functional, vines.^[35]

Tomato plant vines are typically pubescent, meaning covered with fine short hairs. These hairs facilitate the vining process, turning into roots wherever the plant is in contact with the ground and moisture, especially if there is some issue with the vine's contact to its original root.

Most tomato plants have compound leaves, and are called regular leaf (RL) plants. But some cultivars have simple leaves known as potato leaf (PL) style because of their resemblance to that close cousin. Of regular leaves, there are variations, such as rugose leaves, which are deeply grooved, variegated, angora leaves, which have additional colors where a genetic mutation causes chlorophyll to be excluded from some portions of the leaves.^[36]

Their flowers, appearing on the apical meristem, have the anthers fused along the edges, forming a column surrounding the pistil's style. Flowers tend to be self-fertilizing. This is because they are native to the Americas, where there were no honeybees (which are native to the old world). Similarly, many plants of the Americas are self-fertilizing,^[37] while others are pollinated by flies, butterflies, moths, other insects, or other external forces that present in the Americas, that made it possible for some new world plants to originally require biotic pollination.

Tomato fruit is classified as a berry. As a true fruit, it develops from the ovary of the plant after fertilization, its flesh comprising the pericarp walls. The fruit contains hollow spaces full of seeds and moisture, called locular cavities. These vary, among cultivated species, according to type. Some smaller varieties have two cavities, globe-shaped varieties typically have three to five, beefsteak tomatoes have a great number of smaller cavities, while paste tomatoes have very few, very small cavities.

The seeds need to come from a mature fruit, and be dried/fermented before germination.

Botanical classification

In 1753 the tomato was placed in the genus Solanum by Linnaeus as Solanum lycopersicum L. (derivation, 'lyco', wolf, plus 'persicum', peach, i.e., "wolf-peach"). Other species in that family are potatoes, chili peppers, tobacco, eggplant and the poisonous belladonna. However, in 1768 Philip Miller placed it in its own genus, and he named it Lycopersicon esculentum. This name came into wide use but was in breach of the plant naming rules. Technically, the combination Lycopersicon lycopersicum (L.) H.Karst. would be more correct, but this name (published in 1881) has hardly ever been used (except in seed catalogs, which frequently used it and still do). Therefore, it was decided to conserve the well-known Lycopersicon esculentum, making this the correct name for the tomato when it is placed in the genus Lycopersicon.

However, genetic evidence (e.g., Peralta & Spooner 2001) has now shown that Linnaeus was correct in the placement of the tomato in the genus Solanum, making the Linnaean name correct;^[1] if Lycopersicon is excluded from Solanum, Solanum is left as a paraphyletic taxon. Despite this, it is likely that the exact taxonomic placement of the tomato will be controversial for some time to come, with both names found in the literature. Two of the major reasons that some still consider the genera separate are the leaf structure (tomato leaves are markedly different from any other Solanum), and the biochemistry (many of the alkaloids common to other Solanum species are conspicuously absent in the tomato). The tomato can with some difficulty be crossed with a few species of diploid Potato with viable offspring that are capable of reproducing. Such hybrids provide conclusive evidence of the close relationship between these genera.

An international consortium of researchers from 10 countries, among them researchers from the Boyce Thompson Institute for Plant Research began sequencing the tomato genome in 2004 and is creating a database of genomic sequences and information on the tomato and related plants.^[38][39] A draft version of the full genome expected to be published by 2008. The genomes of its organelles (mitochondria and chloroplast) are also expected to be published as part of the project.

Breeding

Active breeding programs are ongoing by individuals, universities, corporations, and organizations. The Tomato Genetic Resource Center, U.S. Department of Agriculture's Agricultural Research Service-Germplasm Resources Information Network (GRIN)[2], AVRDC, and numerous seed banks around the world store seed representing genetic variations of value to modern agriculture. These seed stocks are available for legitimate breeding and research efforts. While individual breeding efforts can produce useful results, the bulk of tomato breeding work is at universities and major agriculture related corporations. University breeding programs are active in Florida, North Carolina, New York, Oregon, and several other states as well as in numerous countries worldwide. These efforts have resulted in significant regionally adapted breeding lines and hybrids such as the Mountain series from North Carolina. Corporations including Heinz, Monsanto, BHNSeed, Bejoseed, etc, have breeding programs that attempt to improve production, size, shape, color, flavor, disease tolerance, pest tolerance, nutritional value, and numerous other traits.

Fruit or vegetable?

Botanically, a tomato is the ovary, together with its seeds, of a flowering plant: therefore it is a fruit. However, the tomato is not as sweet as those foodstuffs usually called fruits and, from a culinary standpoint, it is typically served as part of a salad or main course of a meal, as are vegetables, rather than at dessert in the case of most fruits. As noted above, the term vegetable has no botanical meaning and is purely a culinary term. Originally the controversy was that tomatoes are treated as a fruit in home canning practices. Tomatoes are acidic enough to be processed in a water bath rather than a pressure cooker as "vegetables" require.

This argument has had legal implications in the United States. In 1887, U.S. tariff laws that imposed a duty on vegetables but not on fruits caused the tomato's status to become a matter of legal importance. The U.S. Supreme Court settled the controversy on May 10, 1893 by declaring that the tomato is a vegetable, based on the popular definition that classifies vegetables by use, that they are generally served with dinner and not dessert (Nix v. Hedden (149 U.S. 304)).^[40] The holding of the case applies only to the interpretation of the Tariff Act of March 3, 1883, and the court did not purport to reclassify the tomato for botanical or other purpose. Tomatoes have been designated the state vegetable of New Jersey. Arkansas took both sides by declaring the "South Arkansas Vine Ripe Pink Tomato" to be both the state fruit and the state vegetable in the same law, citing both its culinary and botanical classifications. In 2006, the Ohio House of Representatives passed a law that would have declared the tomato to be the official state fruit, but the bill died when the Ohio Senate failed to act on it. However, in April 2009 a new form of the bill passed, making the tomato the official fruit of the state of Ohio. Tomato juice has been the official beverage of Ohio since 1965. A.W. Livingston, of Reynoldsburg, Ohio, played a large part in popularizing the tomato in the late 1800s.

Due to the scientific definition of a fruit, the tomato remains a fruit when not dealing with US tariffs. Nor is it the only culinary vegetable that is a botanical fruit: eggplants, cucumbers, and squashes of all kinds (such as zucchini and pumpkins) share the same ambiguity.

Pronunciation

The pronunciation of tomato differs in different English-speaking countries; the two most common variants are /təˈmɑːtoʊ/ and /təˈmeɪtoʊ/. Speakers from the British Isles, most of the Commonwealth, and older generations among speakers of Southern American English typically say /təˈmɑːtoʊ/, while most American and Canadian speakers usually say /təˈmeɪɾoʊ/.

The word's dual pronunciations were immortalized in Ira and George Gershwin's 1937 song "Let's Call the Whole Thing Off" (You like /pəˈteɪtoʊ/ and I like /pəˈtɑːtoʊ/ / You like /təˈmeɪtoʊ/ and I like /təˈmɑːtoʊ/) and have become a symbol for nitpicking pronunciation disputes. In this capacity it has even become an American and British slang term: saying /təˈmeɪtoʊ, təˈmɑːtoʊ/ when presented with two choices can mean "What's the difference?" or "It's all the same to me."^{[original research?]}

Safety

Plant toxicity

The leaves, stems, and green unripe fruit of the tomato plant,^[41] as a member of the plant genus Solanum (nightshade), contain the poison solanine, which is toxic to humans and animals. Children have been poisoned by a tea produced from the leaves of the tomato plant. The fresh fruit is, however, harmless.^[41]

2006

A sign posted at a Havelock, North Carolina Burger King telling customers that no tomatoes are available due to the salmonella outbreak.

On October 30, 2006, the U.S. Centers for Disease Control and Prevention (CDC) announced that tomatoes might have been the source of a salmonella outbreak causing 172 illnesses in 18 states.^[42] The affected states included Arkansas, Connecticut, Georgia, Indiana, Kentucky, Maine, Massachusetts, Michigan, Minnesota, North Carolina, New Hampshire, Ohio, Pennsylvania, Rhode Island, Tennessee, Virginia, Vermont and Wisconsin. Tomatoes have been linked to seven salmonella outbreaks since 1990 (from the Food Safety Network).^[43]

2008

A 2008 salmonella outbreak caused the removal of tomatoes from stores and restaurants across the United States and parts of Canada.^[44] As of July 8, 2008, from April 10, 2008, the rare Saintpaul serotype of Salmonella enterica caused at least 1017 cases of salmonellosis food poisoning in 41 states throughout the United States, the District of Columbia, and Canada. As of July 2008, the U.S. Food and Drug Administration suspected that the contaminated food product was a common ingredient in fresh salsa, such as raw tomato, fresh jalapeño pepper, fresh serrano pepper, and fresh cilantro. It is the largest reported salmonellosis outbreak in the United States since 1985. New Mexico and Texas were proportionally the hardest hit by far, with 49.7 and 16.1 reported cases per million, respectively. The greatest number of reported cases occurred in Texas (384 reported cases), New Mexico (98), Illinois (100), and Arizona (49).^[45] There were at least 203 reported hospitalizations linked to the outbreak, it caused at least one death, and it may have been a contributing factor in at least one additional death.^[46] The CDC maintains that "it is likely many more illnesses have occurred than those reported." Applying a previous CDC estimated ratio of non-reported salmonellosis cases to reported cases (38.6:1), one would arrive at an estimated 40,273 illnesses from this outbreak.^[47]

Tomato records

The tomato tree as seen by guests on the Living with the Land boat ride at Epcot, Lake Buena Vista, Florida.

The heaviest tomato ever was one of 3.51 kg (7 lb 12 oz), of the cultivar 'Delicious', grown by Gordon Graham of Edmond, Oklahoma in 1986.^{[citation needed]} The largest tomato plant grown was of the cultivar 'Sungold' and reached 19.8 m (65 ft) length, grown by Nutriculture Ltd (UK) of Mawdesley, Lancashire, UK, in 2000.^{[citation needed]}

The massive "tomato tree" growing inside the Walt Disney World Resort's experimental greenhouses in Lake Buena Vista, Florida may be the largest single tomato plant in the world. The plant has been recognized as a Guinness World Record Holder, with a harvest of more than 32,000 tomatoes and a total weight of 1,151.84 pounds (522 kg). It yields thousands of tomatoes at one time from a single vine. Yong Huang, Epcot's manager of agricultural science, discovered the unique plant in Beijing, China. Huang brought its seeds to Epcot and created the specialized greenhouse for the fruit to grow. The vine grows golf ball-sized tomatoes which are served at Walt Disney World restaurants. The world record-setting tomato tree can be seen by guests along the Living With the Land boat ride at Epcot.

On August 30, 2007, 40,000 Spaniards gathered in Buñol to throw 115,000 kilograms (250,000 lb) of tomatoes at each other in the yearly Tomatina festival. Bare-chested tourists also included hundreds of British, French and Germans.^[48]

Types

It has been suggested that this article or section be merged into List of tomato cultivars. (Discuss)

Varieties commonly grown by home gardeners include^{[citation needed]}:

• 'Beefsteak VFN' (a common hybrid resistant to Verticillium, Fusarium, and Nematodes)
• 'Big Boy' (a very common determinate hybrid in the United States)
• 'Black Krim' (a purple-and-red cultivar from the Crimea)
• 'Brandywine' (a pink, indeterminate beefsteak type with a considerable number of substrains)
• 'Burpee VF' (an early attempt by W. Atlee Burpee at disease resistance in a commercial tomato)
• 'Early Girl' (an early maturing globe type)
• 'Gardener's Delight' (a smaller English variety)
• 'Juliet' (an oblong cherry tomato)
• 'Marmande' (a heavily ridged variety from southern France; similar to a small beefsteak and available commercially in the U.S. as UglyRipe)
• 'Moneymaker' (an English greenhouse strain)
• Mortgage Lifter (a popular heirloom beefsteak known for gigantic fruit)
• 'Patio' (bred specifically for container gardens)
• 'Purple Haze' (large cherry, indeterminate. Derived from Cherokee Purple, Brandywine and Black Cherry)
• 'Roma VF' (a plum tomato common in supermarkets)
• 'Rutgers' (a commercial variety but considered an heirloom)
• 'San Marzano' (a plum tomato popular in Italy)
• 'Santa F1' (a Chinese grape tomato hybrid popular in the U.S. and parts of southeast Asia)
• 'Shephard's Sack' (a large variety popular in parts of Wales)
• 'Sungold F1' (orange cherry variety with distinctive candy like sweetness)
• 'Sweet 100' (a very prolific, indeterminate cherry tomato)
• 'Yellow Pear'' (a yellow, pear-shaped heirloom cultivar)
• 'Cherry' Small, cherry shaped

Many varieties of processing tomatoes are grown commercially, but just five hybrid cultivars grown in California constitute over 60% of total production of processing tomatoes.^[12]

Heritage and heirloom varieties include:

• 'Aunt Ruby's German Green' (spicy green beefsteak type)
• 'Azoykcha' (Russian yellow variety)
• 'Andrew Rahart Jumbo Red' (red beefsteak)
• 'Backfield' (deep red indeterminate beefsteak type)
• 'Black Cherry' (black/brown cherry)
• 'Box Car Willie' (red beefsteak)
• 'Brandywine' (red beefsteak, Sudduth strain)
• 'Cherokee Purple' (purple beefsteak)
• 'Crnkovic Yugoslavian' (red beefsteak)
• 'Earl’s Faux' (pink/red beefsteak)
• 'Elbe' (orange beefsteak)
• 'German Johnson (sweet beefsteak type)
• 'Great Divide' (red beefsteak)
• 'Ispolin' (pink Siberian strain)
• 'Lucky Cross' (bi-color red/orange)
• 'Marianna’s Peace' (red beefsteak)
• 'Mortgage Lifter' (red beefsteak, various strains)
• 'Red Pear' (pear shaped salad cherry type with beefsteak flavor)
• 'Rose' (very large sweet Amish beefsteak type)
• 'Urbikany' (Siberian variety)

Gallery

Unripe tomatoes on a vine, good for pickling.	Small cherry tomatoes in Korea.	Tomatoes on a vine.	Tomato slices.
Young tomato plant.	Tomato plants in the garden.	Tomato Flower.	Heirloom tomatoes in Pico de gallo.
Tomato fruit.	Vine Ripened Tomato	'P20 blue tomato from OSU'

See also

• Tomato stain
• Canned tomatoes
• Tomatillo (Mexican green "tomato")
• Tomberry (Trademarked name of an unusually small cultivar)
• Tomacco
• Flavr Savr
• Arthur B. Howard
• Attack of the Killer Tomatoes

Culinary uses

Pa amb tomàquet

Suquet de peix (Catalan cuisine)

• Barbecue sauces
• Bloody Mary
• Bruschetta
• Fried green tomatoes (food)
• Gazpacho (Andalusian cuisine)
• Insalata Caprese Neapolitan cuisine
• Ketchup
• Pa amb tomàquet (Catalan cuisine)
• Pizza
• Esqueixada
• Salsa
• Tomato juice
• Tomato paste
• Tomato pie
• Tomato purée
• Tomato sauce (common in Italian cuisine)
• Tomato soup

References

• Smith, A. F. (1994). The Tomato in America. University of Illinois Press. ISBN 0-252-07009-7.
• Peralta, I. E. & Spooner, D. M. (2001). Granule-bound starch synthase (Gbssi) gene phylogeny of wild tomatoes (Solanum L. section Lycopersicon Mill. Wettst. Subsection Lycopersicon). American Journal of Botany 88 (10): 1888–1902 (available online).

Footnotes

External links

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Wikispecies has information related to: Solanum lycopersicum

Wikimedia Commons has media related to: Solanum lycopersicum

• Tomato Pests (NCSU) - Overview of the entomological threats to tomato cultivation.
• Tomato Genome Sequencing Project - Sequencing of the twelve tomato chromosomes.
• Solanum lycopersicum L. on Solanaceae Source - Images, specimens and a full list of scientific synonyms previously used to refer to the tomato.
• Tomato core collection database - Phenotypes and images of 7,000 tomato cultivars
• Solanum lycopersicum: facts, development, flower and fruit anatomy
• Solanum lycopersicum at the Encyclopedia of Life
• Tomato cultivation and cultivars
• The On-line Tomato Vine (Keith Mueller) - Comprehensive and practical information on growing and breeding tomatoes.
• How to grow tomatoes - all the info and photos you need to grow your own.
• The case against heirloom tomatoes