Comprehensive analysis of genomic loci associated with glaucousness in wheat (Triticum aestivum L.) through Genome-wide association study.

Wheat (Triticum aestivum L.) is one of the most important cultivated cereal grain crop. The yield and productivity of wheat are profoundly affected by abiotic stresses like drought. The external surface of wheat plants, including the flag leaf, stem, and spikes, features a visible bluish-grey layer of epicuticular wax, commonly referred to as glaucousness. Cuticular wax accumulation in wheat plants under drought stress plays a crucial role in reducing water loss. Present study was carried out to identify marker trait associations (MTAs) associated with glaucousness in wheat. Phenotyping for glaucousness was conducted for three cropping seasons (2019-2020, 2020-2021 and 2021-2022.) represented as Environment first (E1), Environment second (E2), Environment third (E3), and a combined environment (CE). The diverse wheat association panel was genotyped using 13,006 single-nucleotide polymorphisms (SNPs). Multi-locus genome-wide association study was performed through multi-locus random-SNP-effect mixed linear model (mrMLM) and Bayesian-information and linkage-disequilibrium iteratively nested keyway (BLINK) models. Using the mrMLM and BLINK models, 31 and 34 significant MTAs, respectively were identified. Multiple MTAs were co-localized with previously reported glaucousness related genes/MTAs/QTLs. Interestingly, significant MTAs on the short arm of chromosome 2B were identified where the wax-related genes W1 and W3, known to regulate glaucousness in wheat, have been previously reported. Candidate gene (CG) analysis, lead to the identification of potential CGs with protein domains associated with drought stress. Collectively, the significant MTAs and CGs identified in the present study hold substantial potential for improving glaucousness in wheat through the application of marker-assisted selection (MAS) approach.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01624-z.