Deciphering the genetic architecture of fruit color in strawberry

Abstract

Fruits of Fragaria species usually have an appealing bright red color due to the accumulation of anthocyanins, water-soluble flavonoid pigments. Octoploid cultivated strawberry (Fragaria x ananassa) is a major horticultural crop for which fruit color and associated nutritional value are main breeding targets. Great diversity in fruit color intensity and pattern is observed not only in cultivated strawberry but also in wild relatives such as its octoploid progenitor F. chiloensis or the diploid woodland strawberry F. vesca, a model for fruit species in the Rosaceae. This mini-review examines our understanding of fruit color formation in strawberry and how ongoing developments will advance it. Natural variations of fruit color as well as color changes during fruit development or in response to several cues have been used to explore the anthocyanin biosynthetic pathway and its regulation. So far, the successfull identification of causal genetic variants has been largely driven by the availability of high-throughput genotyping tools and high-quality reference genomes of F. vesca and F. x ananassa. The current completion of haplotype-resolved genomes of F. x ananassa combined with QTL mapping will accelerate the exploitation of the untapped genetic diversity of fruit color and help translate the findings into strawberry improvement.

Advances in genomics and genome editing for improving strawberry (Fragaria ×ananassa)

“…Natural mutations in FaMYB10 have been reported as the only natural sources of color variation in strawberry (Castillejo et al, 2020). These findings are supported by those of others, which have identified significant roles of MYB10 and other MYB family genes in controlling anthocyanin accumulation and biosynthesis in strawberry (Whitaker et al, 2020;Denoyes et al, 2023). However, other genes have been reported to impact fruit color in addition to MYB10.…”

Exploration of a European-centered strawberry diversity panel provides markers and candidate genes for the control of fruit quality traits

“…In our GWAS study, we did not detect any previously known color QTL nor CG linked to the MBW complex, probably because white fruit genotypes and flesh-color trait were under-represented in our analysis. However, our diversity panel has enabled us to reveal new skin color QTLs and identify strong CG involved in the successive steps leading to anthocyanin accumulation in strawberry 11 : (i) anthocyanin biosynthesis; (ii) formation of stabilized anthocyanidin-glucosides; and (iii) transport of anthocyanidin-glucosides for storage in the vacuole. Color CG, which deserve further study, include a gene ( CSE ) encoding shikimate esterase, an enzyme involved in lignin pathway that may compete with anthocyanin biosynthesis for common substrates; several genes encoding glycosyltransferases ( GT ), among which the strawberry FaGT1 enzyme that has been shown to generate anthocyanidin 3-O-glucosides 43 and its homolog FaGT2; and a gene encoding a vacuolar flavonoid/H+-antiporter ( TT12 ) that can actively transport cyanidin-3-O-glucoside to the vacuole 44 .…”

“…Another area for improvement is the extension of the storage period and the reduction of post-harvest rot, both of which are linked to fruit firmness 7 and little-explored fruit surface properties 10 . Several fruit quality traits can be easily manipulated using advanced technology, such as genome editing which has successfully been applied to create new alleles modifying various traits including fruit color, sweetness and aroma 7,11 . Other complex (e.g.…”

Image analysis and polyphenol profiling unveil red-flesh apple phenotype complexity

“…Many plant studies rely on colour measurement [10,[28][29][30] and image-based phenotyping [31][32][33][34] to dissect the genetic determinism of colour development. Image-based colour measurement uses mostly colour conversion from RGB (Red Green Blue) images to different colour spaces to quantify colour variations among individuals [35].…”