Dissection of Gene Network Underlying Wheat Milling Yield and Dough Mixing Parameters Using a High-Density SNP-Based Linkage Map.

Wheat (Triticum aestivum L.) is one of the most important crops consumed by humans in the world.  Improvement of end-use quality traits in wheat, such as flour extraction and mixograph characteristics, depends on a deep understanding of the genetic basis of these traits.  The present study aimed to construct a high-density genetic linkage map of 127 F₁₀ recombinant inbred lines (RILs) by applying the Illumina iSelect 90K SNP assay.  The phenotyping of flour extraction rate (FE) and mixograph parameters was done in three environments over three years from 2012 to 2014. Mixograph related traits include mixograph envelope peak time (MEPT), mixograph middle line peak time (MMLPT), mixograph middle peak integral (MMLPI) and general mixograph pattern (Mx) were evaluated. The map contains 8553 single nucleotide polymorphism (SNP) markers with a total coverage of 34972.6 centimorgans (cM) with an average interval of 4.09 cM per marker. Fifteen quantitative trait loci (QTL) were detected by inclusive composite interval mapping (ICIM). Threshold LOD scores for detection of definitive QTL were also calculated based on 1000-permutations. Six QTL for MMLPT were mapped on chromosomes 2A, 1B, 3B, 4D, and 5D with phenotypic variation ranging from 5.33% to 17.53%. Two QTL for MEPT were mapped on chromosomes 4A, and 4D with phenotypic variation ranging from 4.06% to 10.56%.  One QTL for MMLPI was mapped on chromosome 4A with phenotypic variation of 16.26%. Two QTL were mapped for FE on chromosomes 3B and 6B with phenotypic variation ranging between 13.94% to 15.34. This study is a novel resource because it reveals new valuable QTL and could be used by breeders and geneticists for improvement of end-use quality traits in bread wheat.