Development and characterization of a wild emmer wheat backcross introgression population for hard winter wheat improvement

Authors: Price, John; Guttieri, Mary; NYINE, MOSES - Kansas State University; AKHUNOV, EDUARD - Kansas State University

Submitted to: The Plant Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2025
Publication Date: 9/1/2025
Citation: Price, J.H., Guttieri, M.J., Nyine, M., Akhunov, E. 2025. Development and characterization of a wild emmer wheat backcross introgression population for hard winter wheat improvement. The Plant Genome. 18(3). Article e70104. https://doi.org/10.1002/tpg2.70104.
DOI: https://doi.org/10.1002/tpg2.70104

Interpretive Summary: The weedy wild ancestors of modern bread wheat are a reservoir of variation for resistance to diseases, tolerance to heat and drought stress, and nutritional quality. This natural variation was lost in the evolutionary cascade that led to modern bread wheat. This research integrates the variation found in wild emmer wheat, the ancestral source of two-thirds of the genome of modern bread wheat. A set of 27 distinct and diverse wild emmer wheat parents was mated to a set of five hard winter wheats adapted to the Great Plains region of the United States. The hybrids of these matings then were pollinated with the original hard winter wheat parents. The offspring of these matings were advanced by inbreeding to develop of library of 1,601 lines that are then 25% wild emmer and 75% bread wheat, by pedigree. The DNA of the parents was sequenced to identify differences between the wild emmer and bread wheat parents, and then the DNA of the offspring was sparsely sequenced to detect the regions of the genome that are contributed by wild emmer in each one of the 1,601 lines. In this set of lines, wild emmer DNA generally was uniformly distributed across the genome. This set of breeder-ready wheat materials, and the associated DNA sequence information, is a valuable new genetic resource for wheat improvement.

Technical Abstract: Wild emmer wheat (Triticum turgidum subsp. dicoccoides) is the tetraploid progenitor of hexaploid bread wheat (Triticum aestivum L.) and is known to be a valuable source of genetic variation for wheat improvement. However, direct evaluation of wild emmer diversity for agronomic potential has limited value unless performed in the backgrounds of adapted cultivars. Here, we present a genetic characterization of a population of 1,601 backcross recombinant inbred lines, with an average genome composition of 75% bread wheat and 25% wild emmer. Low coverage whole-genome sequencing allowed introgressions and aneuploidies to be identified at relatively low cost per sample. We identified a relatively large proportion of small introgressions (median length 38 Mb), and we found introgressions to be distributed across chromosomes. Approximately 44% of genotyped progeny carried at least one aneuploidy, with monosomies being by far the most common. In all, we believe that this population represents a valuable resource for wheat breeders, and will accelerate the discovery and integration of useful variation from wild emmer wheat.