Development of Wheat-Aegilops caudata Introgression Lines and Their Characterization Using Genome-Specific KASP Markers

Abstract

<i>Aegilops caudata</i> L. [syn. <i>Ae. markgrafii</i> (Greuter) Hammer], is a diploid wild relative of wheat (2n = 2x = 14, CC) and a valuable source for new genetic diversity for wheat improvement. It has a variety of disease resistance factors along with tolerance for various abiotic stresses and can be used for wheat improvement through the generation of genome-wide introgressions resulting in different wheat-<i>Ae. caudata</i> recombinant lines. Here, we report the generation of nine such wheat-<i>Ae. caudata</i> recombinant lines which were characterized using wheat genome-specific KASP (Kompetitive Allele Specific PCR) markers and multi-color genomic <i>in situ</i> hybridization (mcGISH). Of these, six lines have stable homozygous introgressions from <i>Ae. caudata</i> and will be used for future trait analysis. Using cytological techniques and molecular marker analysis of the recombinant lines, 182 KASP markers were physically mapped onto the seven <i>Ae. caudata</i> chromosomes, of which 155 were polymorphic specifically with only one wheat subgenome. Comparative analysis of the physical positions of these markers in the <i>Ae. caudata</i> and wheat genomes confirmed that the former had chromosomal rearrangements with respect to wheat, as previously reported. These wheat-<i>Ae. caudata</i> recombinant lines and KASP markers are useful resources that can be used in breeding programs worldwide for wheat improvement. Additionally, the genome-specific KASP markers could prove to be a valuable tool for the rapid detection and marker-assisted selection of other Aegilops species in a wheat background.