Allelic Variants at the TaZds‐D1 Locus on Wheat Chromosome 2DL and their Association with Yellow Pigment Content

Abstract

ABSTRACTZeta (ζ)‐carotene desaturase (ZDS) is a key enzyme in the carotenoid biosynthetic pathway, which determines the yellow pigment (YP) content in wheat (Triticum aestivum L.) grains. In the present study, the full‐length DNA sequence of a ZDS gene on wheat chromosome 2DL, designated TaZds‐D1, was characterized. The TaZds‐D1 gene has an open reading frame of 1707 bp, including 13 introns and 14 exons, and a deduced peptide containing 568 amino acid residues with a predicted molecular weight of 62.5 kDa. The TaZds‐D1 gene was located on chromosome 2DL based on polymerase chain reaction amplifications of Chinese Spring nullisomic‐tetrasomic lines, Langdon–Chinese Spring D‐genome chromosome disomic substitution lines, and Rusty D‐genome chromosome disomic substitution lines as well as linkage analysis. Two allelic variants, TaZds‐D1a and TaZds‐D1b, were detected in Chinese wheat cultivars, and a functional marker, YP2D‐1, was developed based on the sequence polymorphism between TaZds‐D1a and TaZds‐D1b. A major quantitative trait locus, located at the TaZds‐D1 region in the marker interval of YP2D‐1 and Xgwm157 on chromosome 2DL, explained 18.4% of the phenotypic variance for YP content in a doubled haploid population derived from the cross Zhongyou 9507/CA 9632. This confirmed the association between allelic variation at the TaZds‐D1 locus and YP content.