Generation of Doubled Haploid Wheat-Triticum urartu Introgression Lines and Their Characterisation Using Chromosome-Specific KASP Markers

Abstract

Wheat is one of the most important food and protein sources in the world and although, in recent years wheat breeders have achieved yield gains, they are not sufficient to meet the demands of an ever-growing population. Development of high yielding wheat varieties, resilient to abiotic and biotic stress resulting from climate change, has been limited by wheat’s narrow genetic base. In contrast to wheat, the wild relatives of wheat provide a vast reservoir of genetic variation for most, if not all, agronomic traits. Previous studies by the authors have shown the transfer of genetic variation from T. urartu into bread wheat. However, before the introgression lines can be exploited for trait analysis, they are required to have stable transmission of the introgressions to the next generation. In this work, we describe the generation of 86 doubled haploid (DH) wheat-T. urartu introgression lines that carry homozygous introgressions which are stably inherited. The DH lines were characterised using the Axiom® Wheat Relative Genotyping Array and 151 KASP markers to identify 65 unique T. urartu introgressions in a bread wheat background. DH production has helped accelerate the breeding process and facilitated the early release of homozygous wheat-T. urartu introgression lines. Together with the KASP markers, this valuable resource could greatly advance identification of beneficial alleles that can be used in wheat improvement.

Chromosome‐specific KASP markers for detecting Amblyopyrum muticum segments in wheat introgression lines

“…This was as expected since this set of markers was originally developed to detect T. urartu introgressions in a wheat background (Grewal et al. 2021). When the 13 KASP markers were added to the 150 Am.…”

“…muticum accessions in this study, but only 5.8% of the 224 assays were found to be polymorphic with wheat. This was as expected since this set of markers was originally developed to detect T. urartu introgressions in a wheat background (Grewal et al 2021). When the 13 KASP markers were added to the 150 Am.…”

“…Set 2 KASP markers previously developed and tested on T. urartu introgression lines (Grewal et al. 2021) were tested on wheat parental cultivars and Am. Muticum accessions in this study.…”

“…Previous studies have reported chromosome-specific KASP markers between wheat and Am. muticum (Grewal et al, 2020a) and other wild relative species (Grewal et al, 2020b;Grewal et al 2021), which have been used for genotyping wheat-wild relative introgression lines. The objective of this work was to fill in the gaps with more KASP markers to increase the efficiency of genotyping by using an approach that involved faster SNP discovery and a more robust, chromosome-specific assay design than the ones reported in previous studies.…”

“…muticum (codes between WRC0001‐1000; Grewal et al., 2020a). Set 2 consisted of 224 KASP assays designed to be tested on doubled haploid wheat– Triticum urartu Thumanian ex Gandilyan introgression lines (codes between WRC1080‐1308 and WRC1317‐1393; Grewal et al., 2021). This is a subset of the 304 KASP markers developed in this study after 47 failed to amplify a PCR product and 33 were polymorphic between the parental wheat cultivars.…”