Cloning Of Genes Associated With Grain Yellow Pigment Content In Common Wheat And Development Of Functional Markers

Flour colour is an important quality trait, exerting significant influences on the apparence of wheat-based products, and thus it is of great importance to investigate the genes related to colour for wheat products. In the present study, TaPds-A1, TaPds-B1, TaZds-A1, TaLcye-B1 and TaLcye-D1 were cloned by the method of in silico cloning in combination with PCR amplification, and functional markers were developed for the genes TaPds-B1, TaZds-A1 and TaLcye-B1 according to their allelic varants in different wheat cultivars. The main results are summarized below.1. Full-length genomic DNA sequences of TaPds-A1 and TaPds-B1 on chromosomes 4A and 4B, respectively, were cloned from common wheat. Both have 14 exons, 13 introns and an open reading frame (ORF) of 1,728 bp, encoding 568 amino acid residues. For the two allelic variants TaPds-B1a and TaPds-B1b at TaPds-B1 locus, dominant functional markers YP4B-1 and YP4B-2 were developed, respectively. The two functional markers were used to test the 217 Chinese winter wheats to determine the genotype of TaPds-B1 in the cultivars.2. The full-length DNA sequence of a ZDS gene on wheat chromosome 2A, designated TaZds-A1, was cloned, with 14 exons and 13 introns, and it has an ORF of 1,707 bp, encoding 568 amino acid residues. A co-dominant functional marker, YP2A-1, was designed based on the polymorphisms of two alleles at the locus, TaZds-A1a and TaZds-A1b, yielding 183-bp and 179-bp fragments in TaZds-A1a and TaZds-A1b genotypes, respectively. A new QTL for YP content was detected on chromosome 2A, co-segregating with the functional marker YP2A-1 and TaZds-A1; it explained 11.3% of the phenotypic variance for YP content in a doubled haploid (DH) population from Zhongyou 9507/CA9632. Among 217 Chinese wheat cultivars and advanced lines, the averaged grain YP content of 126 cultivars with TaZds-A1b allele was 7.8% higher than that of 91 cultivars with TaZds-A1a allele.3. Full-length genomic DNA sequences of TaLcye-B1 and TaLcye-D1 on chromosomes 3B and 3D, respectively, were cloned, with 10 exons and 9 introns, and it has an ORF of 1,611 bp, encoding 536 amino acid residues. A dominant functional marker, YP3B-1, was designed based on the polymorphisms of two alleles at TaLcye-B1 locus, TaLcye-B1a and TaLcye-B1b. Using this functional marker, the genotypes of the 217 Chinese winter wheats were identified.