QTL mapping of anthocyanin pigment traits in the carrot root phloem and xylem tissues

BANNOUD, F.; ELLISON, S.; SENALIK, D.; FANZONE, ML; HOREJSI, T.; DA PEÑA HAMPARSOMIÁN, J.; IORIZZO, M.; SIMON, P. W.; CAVAGNARO, P. F.

Cracovia

Conferencia; Carrot and Other Apiaceae Conference - 2nd International Symposium; 2018

International Society for Horticultural Science (ISHS)

The consumption of anthocyanin-rich fruits and vegetables confers protective effects against some chronic diseases, and this has been mainly attributed to the antioxidant and anti-inflammatory properties of these pigments. Purple carrots accumulate anthocyanins in their root, leaves, and other plant tissues and organs. The genetic basis underlying carrot anthocyanin production with regards to its tissue-specific pigmentation is not well understood.In this work, we visually phenotyped purple pigmentation in the root phloem and xylem of an F2 carrot population (N=254) segregating for anthocyanin pigmentation in these tissues. In addition, anthocyanin pigments in the root phloem and xylem (independently) were quantified by HPLC analysis. These phenotypic data and 1013 genotyping-by-sequencing (GBS) marker data were used to construct a carrot genetic map with anthocyanin QTL. Mapping of traits with parametric distribution revealed 18 significant QTL for phloem anthocyanins on chromosomes 3, 4, 6 and 7; and 8 QTL for xylem anthocyanins mapped on chromosomes 3 and 7. Co-localized anthocyanin QTL with highest phenotypic explanatory power for total anthocyanins and individual anthocyanin pigments mapped to two regions of chromosome 3. These regions correspond to those of P1 and P3, the anthocyanin loci previously described. The map position of the leaf petiole pigmentation locus coincided with one of the QTL regions for root pigmentation, namely the P3 region. Ongoing transcriptome analysis (RNA-Seq) in purple and non-purple phloem tissues will likely reveal candidate genes for this trait.