SNP markers associated with agronomic traits under drought and heat stress in wheat

Drought and heat stresses present significant challenges in agriculture production. This study evaluated CIMMYT-Mexico Core Germplasm (CIMCOG) under drought, heat, and their combined stress over two growing seasons. The germplasm was genotyped with a ۳۵K Axiom® Array to identify associations with the studied traits under these environmental conditions. The Best Linear Unbiased Predictors (BLUPs) of each line were used to calculate marker-trait associations using ۱۶۰۶۳ SNP markers with a mixed linear model (MLM). For genome-wide association mapping (GWAM), the highest number of associations was obtained for test weight (۳۲) followed by grain hardness (۱۷). In the case of grain yield, six SNPs were detected in association with the trait only under heat stress conditions. However, with a P value threshold of <۰.۰۰۱, GWAM detected many significant associations (۱۱, ۳۱, ۱۰, and ۱۰ associations under normal, drought, heat, and combined (drought-heat) stress conditions, respectively) distributed nearly across most wheat chromosomes. All detected associated SNPs explained a minimum of ۱۸% of the variance to a maximum of ۳۵.۲%. Among the detected associations, six were common between heat and drought-heat stress conditions. These results may open a new window for breeding programs to improve wheat stress tolerance for abiotic stress tolerance.

کلیدواژه ها:

Abiotic stress tolerance ، GWAS ، single nucleotide polymorphism ، Triticum aestivum