Association mapping unravels the genetics controlling seedling drought stress tolerance in winter wheat

Matías Schierenbeck; Ahmad M Alqudah; Samar G Thabet; Ulrike Lohwasser; María Rosa Simón; Andreas Börner

doi:10.3389/fpls.2023.1061845

Association mapping unravels the genetics controlling seedling drought stress tolerance in winter wheat

Front Plant Sci. 2023 Feb 2:14:1061845. doi: 10.3389/fpls.2023.1061845. eCollection 2023.

Authors

Matías Schierenbeck^{1

2

3}, Ahmad M Alqudah⁴, Samar G Thabet⁵, Ulrike Lohwasser¹, María Rosa Simón^{2

3}, Andreas Börner¹

Affiliations

¹ Genebank Department, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Seeland, Germany.
² Cereals, Faculty of Agricultural Sciences and Forestry, National University of La Plata, La Plata, Argentina.
³ CONICET CCT La Plata, La Plata, Argentina.
⁴ Biological Science Program, Department of Biological and Environmental Sciences, College of Art and Science, Qatar University, Doha, Qatar.
⁵ Department of Botany, Faculty of Science, Fayoum University, Fayoum, Egypt.

Abstract

Drought is a major constraint in wheat (Triticum aestivum L.) grain yield. The present work aimed to identify quantitative trait nucleotides (QTNs)/ candidate genes influencing drought tolerance-related traits at the seedling stage in 261 accessions of a diverse winter wheat panel. Seeds from three consecutive years were exposed to polyethylene glycol 12% (PEG-6000) and a control treatment (distilled water). The Farm-CPU method was used for the association analysis with 17,093 polymorphic SNPs. PEG treatment reduced shoot length (SL) (-36.3%) and root length (RL) (-11.3%) compared with control treatments, while the coleoptile length (CL) was increased by 11% under drought conditions, suggesting that it might be considered as an indicator of stress-tolerance. Interestingly, we revealed 70 stable QTN across 17 chromosomes. Eight QTNs related to more than one trait were detected on chromosomes 1B, 2A (2), 2B, 2D, 4B, 7A, and 7B and located nearby or inside candidate genes within the linkage disequilibrium (LD) interval. For instance, the QTN on chromosome 2D is located inside the gene TraesCS2D02G133900 that controls the variation of CL_S and SL_C. The allelic variation at the candidate genes showed significant influence on the associated traits, demonstrating their role in controlling the natural variation of multi-traits of drought stress tolerance. The gene expression of these candidate genes under different stress conditions validates their biological role in stress tolerance. Our findings offer insight into understanding the genetic factors and diverse mechanisms in response to water shortage conditions that are important for wheat improvement and adaptation at early developmental stages.

Keywords: FarmCPU; GWAS; PEG; breeding; candidate genes; drought tolerance; seedling; winter wheat.

Grants and funding

IPK Gatersleben core funding supported this study. Costs for open access publishing were partially funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, grant 491250510).