Sweet ripe strawberries ( Fragaria spp.) come in colors ranging from deep burgundy to white and everything in between. Such variation attracts consumers and gardeners alike, making fruit color an important breeding target. Strawberry fruit receptacles vary in color due to different levels of anthocyanins.
These water-soluble pigments are synthesized at the endoplasmic reticulum via the well-known flavonoid pathway and transported into the vacuole for storage. However, little is known about the network controlling this trait. The expression of structural genes involved in anthocyanin biosynthesis is fine-tuned by transcription factors such as MYB, bHLH, and WD-repeat proteins.
The R2R3 transcription factor MYB10 activates these genes during strawberry fruit development (Medina-Puche et al., 2014). An 8 bp insertion in the coding region of MYB10 was recently associated with the loss of anthocyanins in a white-fruited octoploid cultivated strawberry ( F, Cristina Castillejo and colleagues (2020) developed a large F 2 mapping population from a cross between red-fruited and white-fruited diploid woodland strawberry ( F. vesca ) accessions and explored the reason behind this variation via mapping-by-sequencing.
A gypsy -transposon detected in MYB10 truncates this protein and knocks out anthocyanin biosynthesis in white-fruited strawberry. This fvmyb10-2 allele co-segregated with the white phenotype at a 1:2:1 ratio, as expected for a single-gene codominant trait. MYB10 target genes in the anthocyanin pathway were not expressed in accessions carrying fvmyb10-2,
However, besides anthocyanins, few metabolites were affected in these lines. Therefore, like red fruits, white fruits with downregulated MYB10 expression are rich sources of nutritional compounds other than anthocyanins. Transient overexpression of FvMYB10, but not fvmyb10-2, restored anthocyanin biosynthesis in a white-fruited accession.
- The authors looked for various fvmyb10 alleles in a large panel of white-fruited woodland strawberry accessions collected worldwide, from Hawaii to Chile to Europe.
- Three different FvMYB10 alleles and a deletion of this gene were uncovered, indicating that mutations in MYB10 occurred independently in diverse ecological niches to drive the natural variation in strawberry fruit color.
Despite this exciting discovery, applying it to cultivated strawberry improvement is challenging due to the octoploid nature of this crop and the frequent homoeologous exchanges that have occurred following polyploidization. To further probe the genetic control of color variation in cultivated strawberry, Castillejo et al.
- Performed a genome-wide association study of F,
- × ananassa populations with a wide range of fruit colors and mapped single nucleotide polymorphisms strongly associated with white fruit skin.
- An analysis of quantitative trait loci most strongly associated with fruit color variation in an interspecific ( F,
× ananassa × F. chiloensis ) population identified a locus harboring 171 annotated genes; again, MYB10 was the most likely causal gene. Genetic and transcriptomic analyses revealed that MYB10-2 is the dominant homoeolog regulating anthocyanin biosynthesis in developing fruit.
The MYB10-2 promoter showed considerable polymorphism among accessions. A CACTA-like transposon in this promoter was associated with ectopic MYB10-2 expression in fruit flesh and anthocyanin production in red-fleshed accessions, in contrast to white-fleshed accessions. Overexpressing MYB10-2 under the control of a constitutive promoter complemented the white-fleshed phenotypes of various accessions (see figure), making this gene ripe for use in CRISPR-Cas9-mediated gene editing and marker-assisted breeding.
Jennifer Lockhart Science Editor [email protected] ORCID: 0000-0002-1394-8947 REFERENCES Castillejo et al. (2020). Allelic variation of MYB10 is the major force controlling natural variation in skin and flesh color in strawberry ( Fragaria spp.) fruit.
- Plant Cell 32: doi:10.1015/tpc20.00474.
- Medina-Puche, L., Cumplido-Laso, G., Amil-Ruíz, F., Hoffmann, T., Ring, L., Rodríguez-Franco, A., Caballero, J.L., Schwab, W., Muñoz-Blanco, J., and Blanco-Portales, R. (2014).
- MYB10 plays a major role in the regulation of flavonoid/phenylpropanoid metabolism during ripening of Fragaria x ananassa fruits.J.
Exp. Bot.65 : 401–417. Wang, H. et al. (2020). The control of red colour by a family of MYB transcription factors in octoploid strawberry ( Fragaria × ananassa ) fruits. Plant Biotechnology Journal 18 : 1169–1184.
How many colors are there in strawberry?
Can Strawberries be Different Colors? – There are some instances where strawberries do not grow in their typical red color. Uniquely colored strawberries have been around for a few decades. These include white, pink, yellow, and golden berries, Colorful fruits and veggies have been around for a long time (purple cabbage and yellow carrots are even considered mainstream now), so it isn’t that far out to want to grow different colored strawberries.
These varieties often stem from crossing wild or alpine strawberry “off-types” and saving the seeds from the subtly different hues. But you have to be wary of photoshopped strawberries on the internet: bright blue, neon pink, bright green, black, or rainbow strawberries don’t exist (in spite of outrageous claims from online retailers selling their seeds or plants).
However, there are some incredible variations on the classic strawberry that will legitimately grow in your garden.
Can you get black strawberries?
Black Strawberries Don’t Exist – KT studio/Shutterstock Plant Carer says that while dark strawberries exist, they are a very dark purple and not jet black. The first faux black strawberry was created by John Robertson for the photographer Jonathan Knowles more than 20 years ago (via Laid Back Gardener ).
It was made of resin and black spray paint. Perhaps this is where the black strawberry rumor began? Real strawberries can and do grow in several colors. Yet, Nu Plant Care warns that black strawberries don’t exist, so don’t fall for this scam. The site also recommends avoiding any online seller claiming to sell black strawberry seeds.
Nu Plant Care recommends only buying from reputable sellers that offer legitimate seeds that bear real fruit, If you’re disappointed to learn that black strawberries don’t exist, take heart. According to Seeds and Spades, you can find strawberries that grow naturally in many other colors, including red, yellow, white, and purple.
Are there strawberries in Africa?
Approximately 300 hectares of strawberries are grown in South Africa and about 80 percent of this area is planted to locally bred cultivars.
What does purple strawberries taste like?
The elusive purple strawberry. Celebrated for its deep, rich, almost regal tones, sweet flavor, and aromatic scent, it’s rarely spotted in grocery stores. But you can grow your own. Developed at Cornell University’s small fruits and breeding program over the course of 13 years, the aptly-named Purple Wonder strawberry made its official debut at the Philadelphia International Flower Show in March 2012 when Cornell partnered with W.
Atlee Burpee Co, At the time, the seed giant was actively seeking new seed varieties to add to its consumer portfolio, particularly those that were easy-to-cultivate berries deemed suitable for backyard growing and container gardening while also being hardy enough to thrive in wide-ranging climates.
Cornell’s Purple Wonder fit the bill and was ready for market. It was a perfect match (per Cornell University). Courtney Weber, a small fruits breeder and associate professor at Cornell University, was the person responsible for developing the Purple Wonder.
She described its taste as being sweet with outstanding strawberry flavor (per Cornell University). But it’s the berries’ unique color that really sets Purple Wonders apart from your average grocery-store strawberries. The plants bear medium-sized berries that ripen from creamy white to red to deep purple-burgundy (per Cornell University).
Unlike regular red strawberries, the regal coloring permeates the entire berry, making it wow-factor worthy when it’s presented as part of a meal.
How many Colours of fruit are there?
Are colours of vegetables and fruits important to health? – Fruit and vegetables fall into five different colour categories: red, purple/blue, orange, green and white/brown. Each colour carries its own set of unique disease fighting chemicals called phytochemicals. It is these phytochemicals that give fruits and vegetables their vibrant colour and of course some of their healthy properties.
Is there strawberry pink?
What are pink strawberries? Have you seen these little pink strawberries at Costco or your local grocery store? They look like underripe strawberries, but they’re not. These little gems are actually pineberries – which is a fusion of the words “pineapple” and “strawberry” although there isn’t any pineapple in them.
- In fact, the pineberry belongs to the strawberry family and is a cross between the strawberries native to North America (Fragaria virginiana) and strawberries native to Chile (Fragaria chiloensis).
- Inside, the flesh is white.
- You may also see these cute little berries called pineberry strawberries or hula pineberries.
What do pineberries taste like? Pineberries have a softer and creamier texture than a red strawberry. There are subtle aromas and flavours of pineapple (thus the name pineberry), pear and apricot. What about nutrition? Both pineberries and strawberries contain vitamin C, folate, fibre and potassium.
Strawberries will have higher levels of “anthocyanins” – which are the healthy plant compounds that give strawberries their beautiful red colour. Since they’re more rare than red strawberries, pineberries tend to be more expensive. How to eat pineberries? Ripe pineberries will have a blush pink colour and bright red seeds.
Eat pineberries the same way you would strawberries! Add them to your yogurt bowl, toss into a salad or add a handful to a snack board. Will you try them? Have you tried them? Tell me what you think in the comments! : What are pink strawberries?