Genetic Mapping of Flavonoid Grain Pigments in Durum Wheat

Abstract

Pigmented cereal grains with high levels of flavonoid compounds have attracted the attention of nutritional science backing the development of functional foods with claimed health benefits. In this study, we report results on the genetic factors controlling grain pigmentation in durum wheat using a segregant population of recombinant inbred lines (RILs) derived from a cross between an Ethiopian purple grain accession and an Italian amber grain cultivar. The RIL population was genotyped by the wheat 25K SNP array and phenotyped for total anthocyanin content (TAC), grain color, and the L*, a*, and b* color index of wholemeal flour, based on four field trials. The mapping population showed a wide variation for the five traits in the different environments, a significant genotype x environment interaction, and high heritability. A total of 5942 SNP markers were used for constructing the genetic linkage map, with an SNP density ranging from 1.4 to 2.9 markers/cM. Two quantitative trait loci (QTL) were identified for TAC mapping on chromosome arms 2AL and 7BS in the same genomic regions of two detected QTL for purple grain. The interaction between the two QTL was indicative of an inheritance pattern of two loci having complementary effects. Moreover, two QTL for red grain color were detected on chromosome arms 3AL and 3BL. The projection of the four QTL genomic regions on the durum wheat Svevo reference genome disclosed the occurrence of the candidate genes Pp-A3, Pp-B1, R-A1, and R-B1 involved in flavonoid biosynthetic pathways and encoding of transcription factors bHLH (Myc-1) and MYB (Mpc1, Myb10), previously reported in common wheat. The present study provides a set of molecular markers associated with grain pigments useful for the selection of essential alleles for flavonoid synthesis in durum wheat breeding programs and enhancement of the health-promoting quality of derived foods.

Genome-wide association study of kernel colour traits and mining of elite alleles from the major loci in maize

“…The GWAS of colour variation in rice, twenty-six loci were identified, and at least three candidates involved in the flavonoid metabolic pathway [ 41 ]. In durum wheat, The genetic mapping identified 4 QTLs disclosed the candidate genes Pp-A3 , Pp-B1 , R-A1 , R-B , bHLH ( Myc-1 ) and MYB ( Mpc1 , Myb10 ) [ 42 ].…”

Trends and Prospects of Genetic and Molecular Research in Plants

“…The results showed that three genotypes carrying homozygous SNPs with a significant effect on the S gene were infected with Oidium neolycopersici , and two had significantly reduced susceptibility to the fungus. Sgaramella et al [ 13 ] used SNP markers to genotype a segregating population of recombinant inbred lines (RILs) obtained by crossing the Ethiopian Purple line of durum wheat with modern durum cultivars. Additionally, the total anthocyanin content (TAC), grain color, and L*, a*, and b* color indexes of whole wheat flour were evaluated in four environments.…”