Wild emmer chromosome arm substitution lines: Useful resources for wheat genetic study and breeding

As the progenitor of durum wheat (Triticum durum Desf.) and common wheat (T. aestivum L.), wild emmer wheat (T. turgidum L. subsp. dicoccoides, TTD) has many valuable alleles for enlarging the genetic pool of common wheat. Chromosome arm substitution lines (CASLs) are useful genetic resources producing genome‐wide variations in the background of certain cultivars, with each CASL containing a pair of an individual chromosome arms from the donor parent. Therefore, CASLs can be used to identify a broad range of phenotypes that are usually different from the parental lines, to map causal genes or quantitative trait loci and to broaden the genetic pools of existing cultivars as prebreeding materials. In this review we summarize recent progress in wheat genetic studies and breeding using two sets of CASLs of the wild emmer accession TTD140 in two common wheat backgrounds of ‘Chinese Spring’ and ‘Bethlehem’. We report the production of CASLs, confirmation of their chromosome structure using molecular markers, and their application in discovering and mapping agronomically important genes. We propose that, together with the release of high‐quality reference genomes of wild emmer and common wheat, wild emmer CASLs are useful resources for genetic study and breeding of wheat