Genome wide association and prediction studies of agronomic and quality traits in spring beard wheat (Triticum aestivum L.) under rain-fed environment with terminal moisture stress

Drought is the principal abiotic stress which affect grain yield and quality of wheat at the global level, more particularly in West and South Asia, North Africa, and sub-Saharan Africa. To identify marker-trait associations (MTA) and putative genes associated with agronomic and quality traits under rain-fed condition, a genome-wide association study (GWAS) was performed using 214 spring bread wheat (Triticum atrium L.) genotypes from the International Center for Agricultural Research in Dry Areas (ICARDA). The study was carried out at Merchouch station in Morocco over a period of 2 years (2018 and 2019). The three best high yielding genotypes G212, G189 and G172 were selected for their excellent grain quality and recorded an average yield of 6.76, 6.72 and 6.67 ton per hectare (t/ha), respectively. A genome-wide association study (GWAS) was performed using the mixed linear model (MLM), where 5841 polymorphic DArT markers were used for genotyping. A total of 42 MTAs (P < 0.05) and 11 genes were detected in this study, where 23 MTAs were recoded for agronomic traits and 19 MTAs were recorded for quality traits. The markers “836,912”, “1,042,644” and “368,094” were the most significant associated markers were significantly correlated with grain yield under rain-fed condition. The markers and candidate genes identified have potentials for marker-assisted selection to develop high yielding wheat genotypes with acceptable end-use quality, tolerance to heat and drought stresses.