Breeding of strawberries facts for kids
The breeding of strawberries is all about choosing and growing different types of strawberries to make them even better! People in Europe started doing this way back in the 1400s. Around the same time, people in Chile were also discovering and growing their own types of strawberries.
Today, the most popular strawberry we eat is called the garden strawberry. Its scientific name is Fragaria × ananassa. This strawberry is a mix of two other types. But there are many kinds of strawberries, and some others are grown too. Strawberry plants have different numbers of chromosomes, which are like tiny instruction manuals inside their cells.
Strawberry growers use many methods to improve these plants. They started with traditional ways, like choosing the best plants to grow new ones. Later, in the 1900s, they began using more advanced science, like molecular breeding and even genetic engineering.
Contents
How Strawberries Were Bred Over Time
Early Days of Breeding
Strawberries in Europe (Before America)
Before people from Europe met people from America, there were three main types of strawberries in Europe: Fragaria vesca, F. viridis, and F. moschata. The most common one grown was F. vesca.
Fragaria vesca
This strawberry is also known as the "woodland strawberry". It has a red variety. One special type, F. sylvestris var. semperflorens, is "ever-bearing." This means it keeps growing flowers and fruit all the time until the cold weather stops it in the autumn.
Fragaria viridis
This one is called the "green strawberry" and comes from the Alps mountains. It's unique because it's "twice-bearing," meaning it grows flowers and fruit two times a year.
Fragaria moschata
People also called this the "musky flavored strawberry" or "Hautboy" in England. It was known for its large fruit and a slightly musky smell.
Strawberries in America (Before Europe)
Fragaria chiloensis
The Mapuche people in Chile were growing this strawberry as early as 1714. Even today, some local types are still grown in Chile and Argentina.
France's Role in Modern Strawberries
The big, tasty strawberries we eat today have their roots in France. In 1714, a French spy brought Fragaria chiloensis from South America to France. This plant had large, delicious fruit.
Once in France, this strawberry was bred with Fragaria virginiana, a strong plant from North America. The mix of these two created the Fragaria × ananassa species, which is our modern garden strawberry!
Antoine Nicolas Duchesne's Discoveries
Antoine Nicolas Duchesne was a very important person in strawberry development. He found out that some strawberry plants have both male and female parts (bisexual), while others have only one (unisexual).
He also experimented by crossing F. moschata and F. chiloensis. The large fruit he grew made King Louis XV happy. This allowed Duchesne to keep studying and categorize ten different "races" of strawberries.
England's Contributions
While France was key, England also helped develop strawberries. The most common strawberry in England was Fragaria virginiana, or the "scarlet strawberry." This was because England had colonies in North America, where F. virginiana naturally grew.
English breeders focused on improving F. virginiana and crossing it with F. chiloensis. They did this because F. chiloensis had big berries and good flavor, but it didn't like England's climate very much. Two important English breeders were Andrew Knight and Michael Keens.
Andrew Knight
Thomas Andrew Knight was one of the people who started the Royal Horticulture Society in 1804. He worked mostly with mixes of F. virginiana and F. chiloensis plants. He created many successful types in his 1817 experiments.
Michael Keens
Michael Keens was not as organized as Knight, but he developed a very popular strawberry type. It was loved for its large size and excellent flavor for a long time, even into the 1900s.
Modern Strawberry Breeding
Today, breeding strawberries is a mix of science and art. The goal is to create plants that can grow enough fruit for everyone, even when conditions are tough or diseases strike.
United States
In 1920, a big change happened in strawberry breeding. It stopped being mostly a private hobby and became a government effort. The United States Department of Agriculture started funding strawberry breeding.
The Plant Patent Act of 1930 gave plant breeders similar rights to inventors. Early goals were to create new types for eating fresh, canning, and freezing. In the late 1930s and 1940s, fighting diseases like red stele root disease became a big focus.
Great Britain
By the 1950s, many American strawberry types were used in Great Britain. In the mid-1950s, new types were released that could resist red stele root disease.
France
Unlike Great Britain and the United States, France let strawberry breeding remain mostly a private study in the early 1900s. This allowed individual breeders to follow their own interests. For example, Charles Simmen worked with ever-bearing strawberries.
Private Companies and Breeding
Many farming businesses now invest in creating their own special strawberry types as part of their research and development.
Strawberry Genetics
Strawberries have different numbers of chromosomes, which are like packages of genetic information. While four numbers are common, some strawberries can have as many as 16 pairs of chromosomes!
Diploid Strawberries
These strawberries have two sets of chromosomes.
- Fragaria daltoniana — found in Asia
- Fragaria nilgerrensis — found in South Asia
- Fragaria nubicola — found in South Asia
- Fragaria vesca — found across Europe, North America, and Northern Asia, plus North Africa, South American mountains, and northern polar areas
- Fragaria viridis — found in Central Europe
Tetraploid Strawberries
These strawberries have four sets of chromosomes.
- Fragaria moupinensis — found in East Central Asia
- Fragaria orientalis — found in Northeast Asia
Hexaploid Strawberries
These strawberries have six sets of chromosomes.
- Fragaria moschata — found in Central Europe
Octaploid Strawberries
These strawberries have eight sets of chromosomes.
- Fragaria chiloensis — found in South Chile and the mountains of Hawaii
- Fragaria ovalis — found in Western North America
- Fragaria virginiana — found in Eastern North America
How Strawberries Are Bred
Traditional Breeding Methods
Traditional breeding is when growers choose certain plants with good traits and let them reproduce together. They pick plants that have the best qualities, like big fruit or good flavor. Then, they grow the new plants and decide which ones are even better. This process continues for many generations.
For a long time, this was the only way humans could change plants and animals. It wasn't until the 1900s that we found other ways to influence their genes.
An Example: Andrew Knight's "Downton" Strawberry
The "Downton" was a successful strawberry type created by Andrew Knight in 1817. The "mother" plant came from seeds directly from America (probably F. Virginiana). The "father" was a type called "Old Black," whose origin isn't fully known. This strawberry was made by pollination, not by directly changing the plant's genes.
Molecular Breeding
Molecular breeding uses tools from molecular biology to help with breeding. It's like using tiny genetic clues to pick the best plants.
Genetic Engineering
Broad spectrum resistance means a plant can fight off many different diseases. Scientists can achieve this quickly in strawberries by adding a special gene called a transgene. For example, adding the Arabidopsis defense gene NPR1 can make strawberries much more resistant to diseases. This works because strawberries have other defense genes that NPR1 can activate.
Example: Cold-Resistant Strawberries
One amazing example of genetic modification is making strawberries resistant to cold. Scientists took genes from the arctic flounder, a fish that lives in very cold water. This fish has a special gene that helps it make a kind of "anti-freeze" to survive.
This gene can be put into bacteria. These bacteria are then sprayed on strawberry plants when it's freezing. The bacteria help the strawberry plant become resistant to the cold. After the cold period, the strawberries are cleaned, and the bacteria are removed.
