Identification and characterization of stripe rust, leaf rust, leaf spot, and common bunt resistance in spring wheat

Abstract

Hundreds of quantitative trait loci (QTLs) have been reported in diverse types of hexaploid wheat (Triticum aestivum L.) populations, but direct comparisons of QTLs in different studies and populations are still challenging due to the lack of physical positions for most QTLs. Here, we used the International Wheat Genome Sequencing Consortium (IWGSC) RefSeq v2.0 physical map of all markers to map QTLs associated with leaf spot (Ls), leaf rust (Lr), stripe rust (Yr), and common bunt (Cbt) resistance in two recombinant inbred line populations. QTL mapping was conducted using the IWGSC physical map of 3158 and 5732 markers and disease severity data of Peace/Carberry and Attila/CDC Go populations evaluated in three to eight environments. We uncovered a total of 82 QTLs associated with Yr (36), Ls (18), Lr (15), and Cbt (13) resistance in the individual and overall means of all combined environments. Among them, 29 were associated with all combined environments, which accounted for 0.5%–20.9% individually and 12.4%–41.2% of the total disease severity per trait. Three (QLr.dms‐2D.2, QLs.dms‐5B, and QYr.dms‐5B.2) of the 29 QTLs were common in both populations. Fourteen out of the 29 QTLs were stable as they were identified both in the overall means and most of the individual environments. Ten chromosome arms harbored a cluster of QTLs associated with resistance to two to four diseases. This methodology would serve as one of the resources to compare QTLs identified in different populations and studies based on the improved physical information of all markers instead of population‐specific and consensus linkage maps.

Intelligent reprogramming of wheat for enhancement of fungal and nematode disease resistance using advanced molecular techniques

“…Ten chromosome arms had QTL clusters for resistance to 2-4 diseases, providing a resource for comparing QTLs in different populations based on physical information of all markers. A total of 82 QTLs related to resistance against Yr (36), Ls (18), Lr (15), and Cbt (13) were discovered by analyzing both individual and combined data from all environments ( Iqbal et al., 2023 ).…”

Physical map of QTLs for some agronomic traits across many environments, identification of related candidate genes, and development of KASP markers with emphasis on terminal heat stress tolerance in common wheat

“…The use of genetic maps has limitations like some inability to compare the correct position of QTLs across genetic maps (Semagn et al 2021a). On the other hand, sequencing-based physical maps like the International Wheat Genome Sequencing Consortium (IWGSC) RefSeq v2.0 (http://wheat-urgi.versailles.inra.fr/) have increased marker density, and enable direct comparison of the correct positions of QTLs across multiple populations (Semagn et al 2021a, b;Iqbal et al 2023).…”

Identification of Fusarium head blight sources of resistance and associated QTLs in historical and modern Canadian spring wheat

“…Most meta-QTLs were physically located within a short interval, which requires further refinement using the International Wheat Genome Sequencing Consortium (IWGSC) RefSeq ( Zhu et al., 2021a ) physical map. In previous studies, we have used the IWGSC physical positions of the Wheat 90K iSelect array ( Wang et al., 2014 ) to characterize QTLs associated with agronomic traits and grain characteristics ( Semagn et al., 2022b ) and reaction to leaf rust, stripe rust, common bunt, and leaf spot ( Iqbal et al., 2023 ) in a historical and modern Canadian spring wheat association mapping panel.…”