Mapping of Quantitative Trait Loci Associated with Productivity and Grain Quality in T. aestivum/T. timopheevii Introgression Line

Most agronomically important traits of wheat are quantitative and controlled by a large number of genes. Not only determining the chromosomal localization of foreign genetic material, but also assessing the degree of its influence on the traits that determine grain productivity and quality, is an important aspect of using relatives and synthetic samples of common wheat as sources of valuable introgressions. The aim of this study was mapping of loci associated with grain protein content and yield structure elements (tiller number, grain number and grain weight per ear, grain weight per plant, and thousand grain weight) in the line 832, obtained by crossing common wheat with the tetraploid wheat Triticum timopheevii Zhuk. Genotyping of the line 832 using SSR markers revealed 11 fragments of varying lengths in the chromosomes 1A, 2A, 2B, 3B, 4A, 4B, 5A, 5B, 6B, and 6D. Based on the evaluation of the traits in F3-4 families of the mapping population (832 × Skala) over three growing seasons, 23 loci were localized, ten of which are located at the fragments of T. timopheevii introgression. Co-localization of several loci responsible for the yield structure traits was noted in adjacent regions of the chromosomes 2A, 5B, 7A, and 7B. No negative effect of T. timopheevii genome fragments on the studied traits was detected, with the exception of a locus on the short arm of chromosome 1A, which reduced the tiller number. It was also shown that the translocation from T. timopheevii on the chromosome 2A contains a genetic factor with a high contribution to grain protein content without reducing the productivity. Introgression fragments in the chromosomes 2A and 5B can have a breeding significance, since they contain a complex of genes influencing resistance to leaf rust pathogen, productivity traits, and grain quality.