Introgression of Recombinant 1RSWR.1BL Translocation and Rust Resistance Genes in Bread Wheat cv. HD2967 Through Marker-Assisted Selection

Bread wheat (Triticum aestivum L.) is one of the major cereal crops utilized worldwide for bread making. The presence of secalin locus on 1RS leads to the sticky dough and poor bread-making quality of wheat. In the present study, two donor parents, one with distal rye chromatin (1RS44:38) and another with distal wheat chromatin (Pavon MA1) without secalin, and one recipient elite wheat cultivar HD2967 were used. In 1RS44:38, the distal rye region has the Pm8 gene to which the QTL for superior root traits is linked, while in Pavon MA1 with Glu-B3/Gli-B1, the Pm8 gene was found to be absent. This distal rye region having root trait QTL was introgressed into the HD2967 derivatives using marker-assisted backcross selection. The derivatives with distal rye region introgression had higher root biomass, drought resistance, and 6-8% higher yield than the recipient parent cultivar. HD2967 is highly susceptible to yellow rust. Therefore, in the second backcross, the rust-resistant version of HD2967 (Lr57 + Yr40) was used to introgress rust resistance in the derivatives. Background selection was done using polymorphic wheat anchored SSR markers of A, B, and D genomes of wheat which led to the selection of derivatives with > 90% background of the recipient cultivar. The significant findings in this study include higher root biomass, improved yield, rust resistance in the derivatives, and retaining the alleles of Glu-B3/Gli-B1 along with Pm8 and the absence of secalin.

Automated summary

This study used marker-assisted backcross selection to introgress a distal rye region with superior root traits into the wheat cultivar HD2967, resulting in derivatives with higher root biomass, yield, and drought resistance. Additionally, rust resistance was introgressed into the derivatives in the second backcross, leading to significant improvements in overall crop performance.