New insights into the genetics of anthocyanin accumulation in carrot

CAVAGNARO, P. F.; IORIZZO, M.; YILDIZ, M.; SENALIK, D.; PARSON, J.; VAN DEYNZE, A.; ELLISON, S.; SIMON, P. W.

Simposio; Carrot and Other Apiaceae International Symposium; 2014

Dietaryanthocyanins provide numerous human health benefits, and purple carrots are oneof the richest anthocyanin sources. Research on anthocyanin genetics andbiochemistry has mainly focused on anthocyanin-containing fruits, leaves andflowers of crops and model plants, with little information reported for storageroots, or for carrots. Purple or ?black? carrots are known to accumulate cyanidinglycosides, in both acylated and non-acylated forms. In an evaluation of a carrotmapping population derived from a cross between a purple and a non-purple(orange) rooted carrot, purple root pigmentation segregated in a pattern consistentwith a two gene model, whereas leaf and petiole purple pigmentation fit asingle dominant gene model. All five anthocyanin glycosides previously reportedin carrot varied quantitatively in this population, and a high resolutionsingle nucleotide polymorphism (SNP)-based map revealed significant QTL for allanthocyanin pigments. QTL mapped to two regions of chromosome 3 with co-localizedQTL for the diverse anthocyanin glycosides. Purple leaf pigmentation, scoredvisually by the presence or absence of purple in the petioles, mapped to one ofthe two regions associated with QTL for root anthocyanins, suggesting that thisQTL may also control leaf pigmentation. Expression analysis of candidate genes thatco-localized with the root anthocyanin QTL revealed differential expression inpurple versus non-purple rooted carrots for 5 candidate genes. Comparativemapping with other carrot populations segregating for purple color indicatedthat the genetic control of purple pigmentation in this population differs fromthat reported previously. These results expand our understanding of the geneticcontrol of anthocyanin pigmentation in carrot, with application to otherspecies.