title: Major QTL for carrot color are positionally associated with carotenoid biosynthetic genes and interact epistatically in a domesticated x wild carrot cross.
abstract: We performed QTL analyses for pigment content on a carotenoid biosynthesis function map based on progeny of a wild white carrot (QAL) which accumulates no pigments x domesticated orange carrot (B493), one of the richest sources of carotenoid pigments-mainly provitamin A alpha- and beta- carotenes. Two major interacting loci, Y and Y(2) on linkage groups 2 and 5, respectively, control much variation for carotenoid accumulation in carrot roots. They are associated with carotenoid biosynthetic genes zeaxanthin epoxidase and carotene hydroxylase and carotenoid dioxygenase gene family members as positional candidate genes. Dominant Y allele inhibits carotenoid accumulation. When Y is homozygous recessive, carotenoids that accumulate are either only xanthophylls in Y(2)__ plants, or both carotenes and xanthophylls, in y(2) y(2) plants. These two genes played a major role in carrot domestication and account for the significant role that modern carrot plays in vitamin A nutrition.
authors: Plant Breeding and Plant Genetics Program, Department of Horticulture, University of Wisconsin, Madison, WI 53706, USA.
authors: Brian J
authors: BJ
authors: Just
authors: Carlos A F
authors: CA
authors: Santos
authors: Brian S
authors: BS
authors: Yandell
authors: Philipp W
authors: PW
authors: Simon
mesh_terms: D002338:Carotenoids / Q000096:biosynthesis / Q000235:genetics*; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003433:Crosses, Genetic; D018552:Daucus carota / Q000235:genetics* / Q000378:metabolism; D004843:Epistasis, Genetic; D017343:Genes, Plant; D040641:Quantitative Trait Loci
chemical_list: D002338:Carotenoids