Breeding of strawberries

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The breeding of strawberries started with the selection and cultivation of European strawberry species in western Europe in the 15th century while a similar discovery and cultivation occurred in Chile. [1] The most commonly consumed strawberry species in modern times is the garden strawberry, a species derived from hybridization of two other species, with the scientific name Fragaria × ananassa, [1] but there are many species of strawberries, several others of which are cultivated to some extent. The strawberry species fall into several different genetic types, based on their number of chromosomes. Strawberry growers have employed many breeding techniques, starting with traditional plant breeding and then moving on to molecular breeding and genetic engineering in the 20th century.

Contents

Watercolor picture of a strawberry plant by Deborah Griscom Passmore in 1890 StrawberryWatercolor.jpg
Watercolor picture of a strawberry plant by Deborah Griscom Passmore in 1890

The history of the breeding of strawberries

Early breeding

European breeding before American contact

In Europe, there were three main strawberry species. They are Fragaria vesca, F. viridis and F. moschata. [1] By the time American plants were introduced, the most commonly grown of these was F. vesca. [1]

Fragaria vesca

A species that has a red variety[ citation needed ]. It is also known as the "woodland strawberry". [1] Of particular interest is F. sylvestris var. semperflorens, a variety of F vesca. F. sylvestris var. semperflorens is unusual, because it is ever-bearing, meaning that it constantly flowers and bears fruit until frosts are too much for it in the autumn. [1]

Fragaria viridis

This species is also known as a "green strawberry". [1] Its origins are in the Alps. A unique characteristic of this plant is that it is twice bearing, [1] meaning that it will flower and bear fruit twice in a year.

Fragaria moschata

Also known as "musky flavoured strawberry" or "Hautboy", in England. [1] This species was known for having large fruit with a slightly musky scent. [1]

American breeding before European contact

Fragaria chiloensis

It was grown by Mapuches as far back as 1714. Modern varieties are still produced on a local scale in Chile and Argentina.

France

The origins of modern large-fruited strawberries can be found in France. In 1714 Fragaria chiloensis , a plant that produces large fruit that is particularly good for eating, was taken from South America to France by a French spy. [1] After its arrival in France, this variety was bred with Fragaria virginiana, a hearty plant from North America. The product of this cross is the species Fragaria × ananassa. [1]

Antoine Nicolas Duchesne

Antoine Nicolas Duchesne is important in the development of strawberries in both France, and the rest of the world. He discovered that strawberries can be either bisexual, or unisexual. [1] He also conducted experiments, crossing F. moschata and F. chiloensis. [1] The resulting large fruit put Duchesne in King Louis XV's favor and allowed him to continue to study and create his categorization of the ten "races" of strawberry. [1]

England

While France did much to establish modern large fruit strawberries, they were not alone in their development of the plant. The most commonly used strawberry was Fragaria virginiana or the "scarlet strawberry". [1] It was commonly used because of the English holdings in North America, F. virginiana’s genetic home. The English work with breeding was centered on breeding F. virginiana into new varieties and crossing it with F. chiloensis. [1] The reason for this was that F. chiloensis has a large berry size and a pleasant flavor but poor tolerance to the climate of England. The English breeding of early F. virginiana x F. chiloensis crosses can be examined by looking at two of the most successful breeders of England: Andrew Knight and Michael Keens.

Andrew Knight

Prior to being one of the founding member of the Royal Horticulture Society in 1804, Thomas Andrew Knight generally refused to read any kind of paper concerning his research interest or publish any of his own findings. [1] However, he eventually became part of the academic community and England benefited greatly from it. His work was mostly with different kinds of F. virginiana x F. chiloensis plants. While he developed many successful varieties in his 1817 breeding experiment, he was mistaken in his belief that all inter-fertile large fruited strawberries were the same species. [1]

Michael Keens

Michael Keens was far less methodical than Knight. He did develop an extremely popular variety that was praised for its large size and excellent flavor up until the 20th century. [1]

Modern breeding

In the modern age, strawberry breeding is a delicate science and art. Its aim is to produce plant varieties that will be able to supply the world's demand for fruit by overcoming adverse conditions and disease.

United States

In 1920 a large shift in the breeding of strawberries occurred. Breeding stopped being a largely private personal endeavor and became a government matter when the United States department of Agriculture started to fund strawberry breeding. [1] The Plant Patent Act of 1930 gave plant breeders the same status as mechanical and chemical inventors had through patent law. [2] The early objectives of the breeding stations were to develop new varieties to better satisfy the American demand for better dessert, canning and freezing varieties. [1] In the late 1930s and 40s disease resistance became an objective of breeding, particularly to red stele root disease. [1] The 1937 federal work objectives included goals of improving resistance to disease and improving tolerance of long and short days as well as high and low temperatures. [1]

Great Britain

By the 1950s many American varieties were being used in Great Britain such as the F. vesca x F. chiloensis [1] In the mid 50s, varieties were released that were resistant to red stele root disease. [1]

France

Unlike Great Britain and the United States, France allowed strawberry breeding to remain a largely private study for the early 20th century. [1] This allowed individual breeders to follow their own curiosity and work with plants that were atypical for the time. A notable example is Charles Simmen's work with ever-bearing strawberries. [1]

Private sector funded breeding

As part of research and development, many agricultural businesses have seen fit to invest in the development of their own varieties.

Genetics of strawberries

Strawberries have many different chromosome numbers. While these are four of the most common numbers of chromosome pairs some strawberries can have as many as 16. [1]

Diploid

Tetraploid

Hexaploid

Octaploid

The breeding techniques

Traditional breeding

Traditional breeding refers to the process of allowing certain chosen plants to sexually reproduce with other plants. Plants are chosen based on favorable characteristics. Simply put, traditional breeding takes plants with favorable characteristics and breeds them. Then the offspring are raised and then judgment is made about which ones have the best traits and the process proceeds to the next generation. This method has been the way that humans have traditionally modified organisms. Not until the 20th century were humans able to influence the genotypes of organisms in any other way.

An example variety developed by Andrew Knight

The "Downton" was a successful variety developed by Andrew Knight as a result of his 1817 breeding experiment. [1] The mother of this variety was a plant grown from seeds direct from America (probably F. Virginiana) and its father was the variety "Old Black", which is of uncertain origin. [1] This variety was created by pollination, not direct manipulation of the plant's genes.

Molecular breeding

Molecular breeding is the application of molecular biology tools in a breeding program.

Genetic engineering

Broad spectrum resistance can be quickly achieved in strawberry by the addition of a transgene, the Arabidopsis defense master regulator gene NPR1 . This quickly produces a large number of changes because of the conservation in strawberry of several other genes. Specifically, these are defense genes that NPR1 interfaces with. [3]

An example of cold resistance

An excellent example of transgenic modification is in the case of cold resistant strawberries. In one particular variety genes from the arctic flounder, a fish that lives in very cold water, were used to give plants resistance to cold. [4] This modification works because of the genetics of the arctic flounder. It lives in water where other fish would freeze to death but, with a special gene that allows it to produce a sort of anti-freeze, it can survive. [4] This gene is put into bacteria that are sprayed on the strawberry during the freezing temperatures, allowing it to also be resistant to cold. The strawberry is then cleaned, removing the bacteria. [ citation needed ]

See also

Related Research Articles

<span class="mw-page-title-main">Berry</span> In the culinary sense, small edible fruit

A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples of berries in the culinary sense are strawberries, raspberries, blueberries, blackberries, red currants, white currants and blackcurrants. In Britain, soft fruit is a horticultural term for such fruits.

<i>Fragaria</i> Genus of strawberry plants

Fragaria is a genus of flowering plants in the rose family, Rosaceae, commonly known as strawberries for their edible fruits. There are more than 20 described species and many hybrids and cultivars. The most common strawberries grown commercially are cultivars of the garden strawberry, a hybrid known as Fragaria × ananassa. Strawberries have a taste that varies by cultivar, and ranges from quite sweet to rather tart. Strawberries are an important commercial fruit crop, widely grown in all temperate regions of the world.

<span class="mw-page-title-main">Strawberry</span> Edible fruit

The garden strawberry is a widely grown hybrid species of the genus Fragaria, collectively known as the strawberries, which are cultivated worldwide for their fruit. The fruit is widely appreciated for its characteristic aroma, bright red color, juicy texture, and sweetness. It is consumed in large quantities, either fresh or in such prepared foods as jam, juice, pies, ice cream, milkshakes, and chocolates. Artificial strawberry flavorings and aromas are also widely used in products such as candy, soap, lip gloss, perfume, and many others.

<i>Fragaria virginiana</i> Species of strawberry

Fragaria virginiana, known as Virginia strawberry, wild strawberry, common strawberry, or mountain strawberry, is a North American strawberry that grows across much of the United States and southern Canada. It is one of the two species of wild strawberry that were hybridized to create the modern domesticated garden strawberry.

<span class="mw-page-title-main">Musk strawberry</span> Species of fruit and plant

The musk strawberry or hautbois strawberry, is a species of strawberry native to Europe. Its French name hautbois strawberry may be anglicised as hautboy strawberry. The plants are hardy and can survive in many weather conditions. They are cultivated commercially on a small scale, particularly in Italy. The fruit are small and round; they are used in the gourmet community for their intense aroma and flavour, which has been compared to a mixture of regular strawberry, raspberry and pineapple. Popular cultivated varieties include 'Capron' and 'Profumata di Tortona'.

<i>Fragaria vesca</i> Species of strawberry

Fragaria vesca, commonly called the wild strawberry, woodland strawberry, Alpine strawberry, Carpathian strawberry or European strawberry, is a perennial herbaceous plant in the rose family that grows naturally throughout much of the Northern Hemisphere, and that produces edible fruits.

<i>Fragaria <span style="font-style:normal;">×</span> vescana</i> Hybrid strawberry

Fragaria × vescana is a hybrid strawberry cultivar that was created in an effort to combine the best traits of the garden strawberry, which has large berries and vigorous plants, with the woodland strawberry, which has an exquisite flavour, but small berries.

<i>Fragaria chiloensis</i> Species of plant

Fragaria chiloensis, the beach strawberry, Chilean strawberry, or coastal strawberry, is one of two species of wild strawberry that were hybridized to create the modern garden strawberry. It is native to the Pacific Ocean coasts of North and South America.

<i>Thielaviopsis basicola</i> Species of fungus

Thielaviopsis basicola is the plant-pathogen fungus responsible for black root rot disease. This particular disease has a large host range, affecting woody ornamentals, herbaceous ornamentals, agronomic crops, and even vegetable crops. Examples of susceptible hosts include petunia, pansy, poinsettia, tobacco, cotton, carrot, lettuce, tomato, and others. Symptoms of this disease resemble nutrient deficiency but are truly a result of the decaying root systems of plants. Common symptoms include chlorotic lower foliage, yellowing of plant, stunting or wilting, and black lesions along the roots. The lesions along the roots may appear red at first, getting darker and turning black as the disease progresses. Black root lesions that begin in the middle of a root can also spread further along the roots in either direction. Due to the nature of the pathogen, the disease can easily be identified by the black lesions along the roots, especially when compared to healthy roots. The black lesions that appear along the roots are a result of the formation of chlamydospores, resting spores of the fungus that contribute to its pathogenicity. The chlamydospores are a dark brown-black color and cause the "discoloration" of the roots when they are produced in large amounts.

Xanthomonas fragariae is a species of bacteria. It causes a leaf spot disease found in strawberries. The type strain is NCPPB1469 from Fragaria chiloensis var. ananassa.

<span class="mw-page-title-main">Marshall strawberry</span> Variety of fruit

The Marshall strawberry is a cultivated variety of Fragaria ananassa, that is known for an "exceptional" taste and had been described as "the finest eating strawberry" in America.

Strawberry crinkle cytorhabdovirus, commonly called Strawberry crinkle virus (SCV), is a negative sense single stranded RNA virus that threatens strawberry production worldwide. This virus reduces plant rigidity, runner production, fruit size, and production, while causing distortion and crinkling of the leaves. This virus was first described in 1932 in Oregon and California with commercial strawberry varieties, and later became an issue around the world, including North America, South America, Europe, South Africa, New Zealand, Australia, and Japan. Of the family Rhabdoviridae, it is a large family of viruses that affects plants, vertebrates, and invertebrates. Specifically, this virus infects strawberry plants of the genus Fragaria and is transmitted through two aphid vectors that feed on strawberries, Chaetosiphon fragaefolii and C. jacobi. When SCV is combined with other aphid-transmitted strawberry viruses, such as mottle, mild yellow-edge, vein banding, or pallidosis, the damage becomes even more deleterious. Economically, the only significant host of SCV is Fragaria ananassa.

Strawberry mild yellow-edge virus (SMYEV) is a pathogenic plant virus.

Fragaria × bringhurstii is a naturally occurring hybrid species of wild strawberry native to the West Coast of the United States. The species results from the natural intercrossing of Fragaria vesca and Fragaria chiloensis, native species whose ranges overlap in that region.

<span class="mw-page-title-main">Pineberry</span> Strawberry cultivar

Pineberry is a white strawberry cultivar with red seeds and a pineapple-like flavor.

<span class="mw-page-title-main">Sanguiin H-6</span> Chemical compound

Sanguiin H-6 is an ellagitannin.

Fragaria pentaphylla is a tetraploid species of wild strawberry native to China. In Chinese, it is called the "five-leaf strawberry".

<span class="mw-page-title-main">Strawberry cultivation in California</span>

Strawberries in the United States are almost entirely grown in California – 86% of fresh and 98% of frozen in 2017 – with Florida a distant second. Of that 30.0% was from Monterey, 28.6% from Ventura, 20.0% from Santa Barbara, 10.0% from San Luis Obispo, and 9.2% from Santa Cruz. The Watsonville/Salinas strawberry zone in Santa Cruz/Monterey, and the Oxnard zone in Ventura, contribute heavily to those concentrations.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 Darrow, G. M. (1966). The strawberry; history, breeding, and physiology (1st edition ed.) Holt, Rinehart and Winston (PDF).
  2. Goodyear, Dana (14 August 2017). "Strawberry Valley". The New Yorker . Retrieved 16 August 2017.
  3. Li, Wei; Deng, Yiwen; Ning, Yuese; He, Zuhua; Wang, Guo-Liang (2020-04-29). "Exploiting Broad-Spectrum Disease Resistance in Crops: From Molecular Dissection to Breeding". Annual Review of Plant Biology . Annual Reviews. 71 (1): 575–603. doi: 10.1146/annurev-arplant-010720-022215 . ISSN   1543-5008. p. 587, '4.5. Altered Expression of Defense-Signaling and Pathogenesis-Related Genes Engineering BSR is possible using both defense signaling and PR genes because they usually function downstream of the immune receptors. ... Defense signaling and PR genes are conserved in different plant species, allowing BSR to be achieved in many crops by expressing the Arabidopsis defense master regulator NPR1 (...164...).'
  4. 1 2 Brody, J.E. (December 5, 2000). "Personal Health; Gene Altered Foods: A Case Against Panic". New York Times. Retrieved 8 November 2011.