A Multiple Synthetic Derivatives population for mining Aegilops tauschii traits and genes in a background of common wheat

Aegilops tauschii represents a vast and rich resource for enhancing wheat (Triticum aestivum L.) genetic diversity by providing new alleles and genes for yield, climate resilience, and other important traits; however, its systematic exploration may not be assured due to many factors, including the wide genetic distance and dissimilarity to the hexaploid wheat. This study aims to describe and present the Multiple Synthetic Derivative (MSD) population for registration as a germplasm resource to mine desirable climate-smart traits or genes from Ae. tauschii more systematically and efficiently. The MSD population was developed by crossing and backcrossing the Japanese wheat cultivar, ‘Norin 61’ (N61) to 43 different primary synthetics (PS) derived from a diverse set of 43 Ae. tauschii accessions. Evaluation of the MSD population under various abiotic stresses including heat, drought, low nitrogen (N) and phosphorus (P), demonstrated wide phenotypic diversity for all traits including grain yield, biomass, days to heading, and stress tolerance index (STI). Across all environments, the maximum grain yield and biomass recorded by some MSD lines were always higher than that of the recurrent parent (N61) and both heat-stress adapted varieties, Goumria and Imam. The MSD population showed a wide range in days to heading. The maximum STIs for heat, drought, low N and P of some MSD lines were higher than that of N61, Goumria, and Imam. Our results indicated the usefulness and effectiveness of MSD population as a platform for mining and exploiting heat, drought, and nutrient-use efficient traits in a common hexaploid wheat background. Therefore, description and registration of the MSD population by Arid Land Research Center, Tottori University, Japan could greatly facilitate efficient mining climate-resilient traits in the background of hexaploid wheat lines derived from diverse Ae. tauschii accessions.