Genome-wide association study of drought-related resistance traits in Aegilops tauschii

Abstract

The D-genome progenitor of wheat (Triticum aestivum), Aegilops tauschii, possesses numerous genes for resistance to abiotic stresses, including drought. Therefore, information on the genetic architecture of A. tauschii can aid the development of drought-resistant wheat varieties. Here, we evaluated 13 traits in 373 A. tauschii accessions grown under normal and polyethylene glycol-simulated drought stress conditions and performed a genome-wide association study using 7,185 single nucleotide polymorphism (SNP) markers. We identified 208 and 28 SNPs associated with all traits using the general linear model and mixed linear model, respectively, while both models detected 25 significant SNPs with genome-wide distribution. Public database searches revealed several candidate/flanking genes related to drought resistance that were grouped into three categories according to the type of encoded protein (enzyme, storage protein, and drought-induced protein). This study provided essential information for SNPs and genes related to drought resistance in A. tauschii and wheat, and represents a foundation for breeding drought-resistant wheat cultivars using marker-assisted selection.

Dissection of Phenotypic and Genetic Variation of Drought‐Related Traits in Diverse Chinese Wheat Landraces

“…For example, 0.23 and 0.18 were the measured values for DRS under drought and normal conditions, respectively, thus, DI = 1.28. D-values were calculated according to previously published methods (Xie, 1993;Zhou et al, 2003;Qin et al, 2016):…”

A genome‐wide association study of 23 agronomic traits in Chinese wheat landraces

“…Marker‐assisted selection (MAS) is considered to be an excellent approach for crop precision breeding, as it improves breeding efficiency and predictability, and thus accelerates breeding progress (Collard and Mackill, ).With the rapid development of next‐generation sequencing (NGS) and high‐density marker genotyping techniques, genome‐wide association study (GWAS) has become an increasingly popular and efficient method for identifying genes responsible for the quantitative variation of complex traits (Zhu et al ., ), which should be helpful in developing valuable genetic markers and performing molecular crop breeding. GWAS has been widely used for studying complex traits in various plant species such as Arabidopsis (Atwell et al ., ; Bac Molenaar et al ., ), rice (Huang et al ., ; Zhou et al ., ), maize (Li et al ., ; Yang et al ., ), Aegilops tauschii (Liu et al ., ,b; Qin et al ., ), and wheat (Liu et al ., ; Arruda et al ., ; Maccaferri et al ., ; Sukumaran et al ., ; Gao et al ., ). Progress in NGS has reduced the cost of DNA sequencing, thereby facilitating the genotyping‐by‐sequencing (GBS) of highly diverse species with large genome sizes (Elshire et al ., ).…”

Wheat genetic resources in the post-genomics era: promise and challenges

“…Among primary gene pool species, Ae. tauschii collections have been widely targeted for GWAS of morphological traits (Liu et al, 2015b), phosphorus deficiency (Liu et al, 2015a) and drought tolerance (Qin et al, 2016), and several genomic regions were identified. Spelt wheat (T. spelta), now gaining favour in several parts of the world (Longin and Wurschum, 2016), was also used in GWAS for agronomic and disease resistance traits using a 15K SNP array (Würschum et al, 2017).…”