Genetic mapping of agronomically important traits in einkorn wheat

Abstract

Bread wheat, a global staple food, has seen a significant reduction in genetic diversity due to domestication and intensive breeding. Diploid einkorn wheat (Triticum monococcum L.) is a valuable resource for enhancing the genetic pool of bread wheat. A linkage map spanning 1033 cM was constructed using 81 recombinant inbred lines (RILs) derived from a cross between cultivated Triticum monococcum ‘DV92’ and wild Triticum boeoticum ‘G3116.’ The RILs were phenotyped in up to eight environments for 24 agronomically important traits, including plant height, tiller number, plant architecture, leaf pubescence, ear emergence time, and spike- and grain-related traits. QTL analyses revealed 167 quantitative trait loci (QTLs) distributed across all chromosomes, of which 36 QTLs were mapped in intervals of less than 10 cM, and 77 QTLs explained more than 10% of the phenotypic variance for a trait, with a maximum of 56.2% (the drought resistance-related leaf pubescence). Verification using 407 F₂ genotypes confirmed that over 30% of the QTLs were highly reproducible. In addition, we have demonstrated that the identified QTLs can be readily characterized by fine-mapping of a novel QTL for leaf pubescence, QLP.ieb-3A, on chromosome 3A^m. This study provides valuable insights into loci influencing key agronomic traits, such as yield and resistance to abiotic stress, and is suitable for bread wheat gene pool enrichment. Additionally, the findings facilitate map-based cloning of the underlying genes, paving the way for functional studies and efficient application of the loci in wheat breeding programs.