Identification of novel major quantitative trait loci associated with selenium and zinc accumulation in Aegilops...

Crop selenium and zinc biofortification relies heavily on bioaccumulation efficiency, whereas the genetic and molecular mechanisms mediating selenium (Se) and zinc (Zn) accumulation in Aegilops tauschii are still poorly understood. In this study, quantitative trait locus (QTL) mapping was carried out for selenium and zinc content in a recombinant inbred line (RIL) population derived from a cross between AS2407 (Aegilops tauschii subsp. strangulata) and AS65 (Aegilops tauschii subsp. tauschii). Two major QTLs, QSe-1D and QZn-2D, controlling Se and Zn content were identified on chromosomes 1D and 2D, respectively. QSe-1D was mapped to a 0.5 cM interval with 11.94% phenotypic variance explained (PVE), while QZn-2D was located within a 1.1 cM interval and explained 13.49% PVE. Through an integrated analysis of functional annotation, expression data, and conserved domain variations, we identified three putative genes linked to indirect selenium accumulation mechanisms and three candidates involved in zinc metabolism as the most promising targets. SSR markers (SSR-1D7 and SSR-2D2) closely linked to these two QTLs were developed, and their predictive efficiency was validated in a natural population consisting of 126 Ae. tauschii accessions. These findings contribute to deciphering the genetic basis of Se and Zn accumulation, offering theoretical references for marker-assisted selection in biofortification breeding.