An adult plant stripe rust resistance gene maps on chromosome 7A of Australian wheat cultivar Axe

Abstract

Australian wheat cultivar Axe produced resistant to moderately resistant stripe rust responses under eld conditions and was exhibiting seedling response varying from 33C to 3+ under greenhouse conditions. Experiments covering tests at different growth stages (2 nd , 3 rd and 4 th leaf stages) demonstrated the clear expression of resistance at the 4 th leaf stage under controlled-environment greenhouse conditions. A recombinant inbred line (RIL) population was developed from the Axe/Nyabing-3 (Nyb) cross. Genetic analysis of Axe/Nyb RIL population in the greenhouse at the 4 th leaf stage showed monogenic inheritance of stripe rust resistance. Selective genotyping using the iSelect 90K In nium SNP genotyping array was performed and the resistance locus was mapped to long arm of chromosome 7A and named Yr75. The Axe/Nyb RIL population was genotyped using a targeted genotype-by-sequencing (tGBS) assay and the resistance-linked SNPs were converted into kompetitive allele speci c PCR (KASP) markers. These markers were tested on the entire Axe/Nyb RIL population and markers sunKASP_430 and sunKASP_427 showed close association with Yr75 in Axe/Nyabing-3 RIL population. A high-resolution mapping family of 1032 F 2 plants from the Axe/Nyb cross was developed and genotyped with sunKASP_430 and sunKASP_427 and these markers anked Yr75 at 0.3 cM and 0.4 cM, respectively. These markers covers 1.24Mb of the physical map of Chinese Spring and can be used for future map-based cloning of this gene.

Genomics-informed prebreeding unlocks the diversity in genebanks for wheat improvement

“…3ce and Supplementary Table 22). Some associated regions were co-located with known, but not yet cloned resistance genes loci such as Yr17 (2AS) 26,27 and Yr75 (7AL) 38 , which have been widely deployed in elite cultivars (Fig. 3c-e and Supplementary Table 23).…”

Physiological specialization of Puccinia triticina and genome-wide association mapping provide insights into the genetics of wheat leaf rust resistance in Iran

“…Our data shed light into the potential employment of the effective Lr genes like Lr2a, Lr28 and Lr19 that are of interest to wheat breeding programs to improve the resistance of Iranian wheat cultivars against leaf rust. terization of novel resistance sources is the prerequisite and most important strategy for controlling rust diseases in wheat and pyramiding these genes for durable resistance 33,34 . The rapid evolution of pathogens due to fungicide application, environmental conditions and also narrow genetic base of resistance genes in improved wheat genotypes can easily lead to the breakdown of the resistance genes 17,35 .…”

Genome-Wide QTL Mapping for Stripe Rust Resistance in Winter Wheat Pindong 34 Using a 90K SNP Array

“…A locus conferring ASR was controlled by a major gene, Yrzhong12 -1, located in the interval of SSR markers Xcfd20 (3.1 cM) and Xbarc121 (4.9 cM) on chromosome 7AL (Ma et al, 2015 ). Kanwal et al ( 2021 ) identified the adult-plant stripe rust resistance gene Yr75 in the Australian wheat cultivar Axe and mapped the gene on the long arm of chromosome 7A, and the two SNP markers sunKASP_430 and sunKASP_427 were closely linked to the gene.…”