Tomato Taxonomy

Tomatoes of different shapes, sizes and colours

Tomatoes of different shapes, sizes and colours (Foxys_forest_manufacture, iStockphoto)

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A look at the taxonomic classification of the tomato plant and the origin, history and development of tomatoes.

Taxonomy

Tomatoes, peppers, potatoes and eggplants all belong to the Solanaceae family of flowering plants. Plants in this family are also called nightshades. There are more than 3000 species of nightshades. Many of them are important to our economy.

There are more than 7000  of tomatoes alone. But all of these make up only one  of tomato. This species is called S. lycopersicum.

Misconception Alert

The different kinds of tomatoes you grow or buy at the store are all varieties of the same species. Roma, cherry, beefsteak tomatoes, etc. are all Solanum lycopersicum

Tomato Taxonomic Classification

Tomato taxonomy chart
Rank Scientific Name Common Name
Kingdom Plantae Plants
Subkingdom Tracheophyta Vascular plants
Superdivision Spermatophyta Seed plants
Division Angiosperms Flowering plants
Class Magnoliopsida Dicotyledons
Subclass Asteridae Astrids
Order Solanales  
Family Solanaceae Nightshades
Genus Solanum  
Species Solanum lycopersicum Garden tomato

What's in a Name?

Tomatoes have had a few different scientific names over the years. Names like Solanum lycopersicum and Lycopersicon esculentum. The names have changed because scientists have changed how they thought tomatoes are related to other plants.

In the early 1700s, a botanist named Carl Linnaeus put tomatoes into the  Solanum. He made this decision based on what he could see about the plants.

In the mid-1700s, another botanist, Philip Miller, did not agree with Linnaeus's  He placed tomatoes into the genus Lycopersicon instead. He thought that tomatoes belonged in a different genus from poisonous nightshade species.

Recently,  reclassified tomatoes again. They put them back into the genus Solanum. They made this decision based on information they learned about tomato genes, using genetic research methods.

This story shows that scientific knowledge doesn’t stay the same forever. It changes all the time, as scientists learn new information.

Origins

Wild tomato plants come from the Andean region of South America. This area includes the countries of Peru, Bolivia, Chile and Ecuador. Scientists think that Aztec and Inca people grew tomatoes as early as 700 The tomatoes they grew were a very different size from the tomatoes we have today. They also tasted different.

Size comparison between the tomato fruits that we eat today on the left to the tiny wild relative on the right
Size comparison between the tomato fruits that we eat today on the left to the tiny wild relative on the right (Source: rekemp via iStockphoto)
Image - Text Version

Shown is a colour photograph of two tomatoes against a white background. The tomato on the left is very large and has more of a wide oval shape. It is a deep red colour. The tomato on the right is about a tenth of the size of the tomato on the left. It has more of a spherical shape and also has a deep red colour.

We don’t know who first brought tomato seeds to Europe, but descriptions of tomatoes appeared in some of the earliest European books about These were written in the 16th century. More  of the tomato plant happened in Europe in the 18th and 19th centuries.

There is no clear evidence of how tomatoes came to North America. Scientists think it happened sometime in the 16th or 17th century. People were growing tomatoes in the United States by the middle of the 18th century. They weren’t popular, though. Many people thought they were poisonous because they belonged to the nightshade

There are stories that in the early 1800s, famous Americans would eat tomatoes in front of audiences just to prove they were not poisonous. No one knows whether or not these stories are true. Eventually Americans realized tomatoes were not poisonous. But they were still unpopular because many people thought they tasted too acidic.

Domestication 

Tomatoes come in many different shapes, colours and sizes.

People create this variety through or selective breeding. They breed tomato plants in order to choose the characteristics they want. Some characteristics include producing more fruit per plant, better shelf life (fruit will last longer before it rots), more resistance to pests, better taste, different size, shape, colour or weight, and more nutritional value.

Many varieties of tomatoes are pictured. Tomatoes come in all different colours, shapes, and sizes.
A basket containing a variety of tomatoes (Source: andreas N via Pixabay).
Image - Text Version

Shown is a colour photograph of a basket of tomatoes. The basket is square and made of wicker painted white. The basket is about half full of tomatoes of a variety of shapes, from ovals to spheres. Sizes range from small grape-sized tomatoes to larger tomatoes that would fill the palm of your hand. The tomato colours range from yellows and oranges to reds, pinks and burgundy. Some even have green stripes!

By the end of the 19th century, many farmers and gardeners were breeding tomatoes. They kept the seeds from the tomatoes they grew and planted them again the next year. This is called seed saving. It has led to what we now call  Heirloom tomato plants produce fruit in many different shapes, sizes and colours. They are   This means that new plants have the same characteristics as their parent plants.

Large-scale breeding of tomatoes for commercial sale began in the early 20th century. This produced  Hybrid tomatoes are the offspring of two different tomato varieties. Hybrids often have the best characteristics of each of their parent plants. This makes them highly desired. Commercial farmers who grow hybrid tomatoes are discouraged from using their own seeds from previous years. They are required to purchase seeds from a seed company. This is to make sure that all the tomatoes they grow are of the same quality. This way they can be sold to grocery stores and food processors.

Did you know?

Tomatosphere™ seeds are a hybrid variety of tomato from the seed producer Heinz Seed. 

Tomato Genetics 

Scientists are finding out more about which tomato  are linked to characteristics like colour and size. This is because of progress in the study of  They have also been able to create new tomato varieties using genetic engineering. This can be done in many ways. Usually scientists change genes so that the characteristics they want appear in the plant.

In 1994, the 'FlavrSavr' tomato was the first genetically engineered tomato sold in stores. This tomato  did not ripen as fast or soften as quickly as conventional tomatoes. This made it easier to pick and ship these tomatoes without damaging them. The 'FlavrSavr' did not make enough money in the end. It cost too much to grow and ship. There were also negative stories about it in the media, so it was no longer sold.

Plant breeders are always working on ways to improve tomatoes. For instance, heirloom tomatoes often taste better than store-bought ones. In 2012, researchers identified a gene responsible for the taste of heirloom tomatoes. This gene was missing from tomatoes that were artificially selected to last longer. Hopefully, we will soon be able to create a long-lasting and super tasty tomato thanks to this discovery.

Learn More

Who was Linnaeus?
Stories and videos about the life and work of Carl Linnaeus from The Linnean Society.

Taxonomy: Life's Filing System (2012)
Video (12:15 min.) from Crash Course explaining the history and importance of taxonomy.

The Original Genetically Modified Tomato You'll Never Eat Again (2013)
Brief story by Ashley Feinberg and longer video (10:52 min.) feature about the Flavr Savr tomato.

References

Bai, Y., & Lindhout, P. (2007). Domestication and breeding of tomatoes: What have we gained and what can we gain in the future? Annals of Botany, 100(5). 1085-1094. DOI: 10.193/1ob/mcm150

Bruening, G., & Lyons, J.M. (2000). The case of the FLAVR SAVR tomatoCalifornia Agriculture, 54(4). 6-7.

The Editors of Encyclopaedia Britannica. (2015). Solanaceae plant family

Encyclopedia.com. (2020). Miller, Phillip.

Ianotti, M. (2019). Difference Between Heirloom, Hybrid, and GMO Vegetables https://www.thespruce.com/hybrid-vs-heirloom-vegetables-1403361

Integrated Taxonomic Information System. (n.d.). Solanum lycopersicum L.

LeHoullier, C. (2015). The history of tomatoes in America. GRIT Magazine.

Sato, S., Tabata, S., Hirakawa, H. et al. (2012). The tomato genome sequence provides insights into fleshy fruit evolution. Nature, 485. 635-641. DOI: 10.1038/nature11119

Solanaceae Source. (2014). Phylogeny.

University of California - Davis. (2014). Genetic history of tomatoes revealed by new sequencing. ScienceDaily.

United States Department of Agriculture, Natural Resources Conservation Service. (n.d.). Classification for Kingdom Plantae Down to Family Solanum L.