Genome‐Wide Association Mapping for searching novel leaf rust seedling resistance loci in Iranian bread wheat germplasm

Abstract

Leaf or brown rust caused by Puccinia triticina Eriks. (Pt) is a limiting factor for wheat production. Thus, a constant search for new resistance genes or QTLs is essential to improve the resistance durability against the continued evolution of new races of Pt. This study was aimed at exploring potentially novel genes/QTLs resistance to leaf rust in Iranian wheat landraces and cultivars by using association mapping. Using a panel of 320 wheat accessions, genome-wide association study (GWAS) genotyping-by-sequencing (GBS) techniques were adopted to map loci associated with resistance to five races of Pt. A total of 17 major marker-trait associations (MTAs) were found on wheat chromosomes that were significantly linked with seedling resistance to Pt. Three markers including rs12954, rs15705, and rs42447 were detected as novel loci for resistance to PKTTS race. Our findings presented new and putative resources of leaf rust resistance in Iranian bread wheat accessions. The new identified SNPs will be valuable to expand the set of resistance genes available to control this serious disease.

QTL mapping for seedling and adult plant resistance to stripe and leaf rust in two winter wheat populations

“…Previously, several leaf rust ASR genes including Lr2a, Lr3, Lr3a, Lr9, Lr11, Lr15, Lr17, Lr18, Lr20, Lr22a, Lr32, Lr36, Lr37, Lr38, Lr39, Lr41, Lr45, Lr47, Lr52, Lr53, Lr59, 65, Lr77, Lr79, and Lr80 were identified on chromosomes 2A, 2D, 3B, 3D, 5B, 6B, 6D, and 7A, respectively (Kumar et al, 2022); whereas in our study, 11 QTLs were mapped on the same chromosomes. Furthermore, previously, few leaf rust ASR QTLs were identified on the same chromosomes at different locations (Gao et al, 2016;Li et al, 2016;Delfan et al, 2023). A maximum of 22 QTLs were found on different chromosomes covering all three subgenomes for yellow rust APR.…”

“…The recent advancements in nextgeneration sequencing (NGS) technologies, the development of the wheat reference genome (IWGSC, 2018), and the cost reduction of genotyping made the genetic dissection of QTL regions and candidate genes more precise and effective. Previously, various mapping populations and marker systems were used to locate QTLs for LR resistance (Kolmer, 2015;Li et al, 2016;Kthiri et al, 2019;Bokore et al, 2020;Ciechanowskaa et al, 2022;Delfan et al, 2023). Similarly, several QTLs were identified for SR resistance in different genetic backgrounds (Wang et al, 2015;Farzand et al, 2021;Rollar et al, 2021;Yuan et al, 2020;Cheng et al, 2022;Rauf et al, 2022;Tehseen et al, 2022).…”