High-density molecular characterization and association mapping in Ethiopian durum wheat landraces reveals high diversity and potential for wheat breeding

摘要

Durum wheat (Triticum turgidum subsp. durum) is a key crop worldwide, yet its improvement\udand adaptation to emerging environmental threats is made difficult by the limited amount of\udallelic variation included in its elite pool. New allelic diversity may provide novel loci to\udinternational crop breeding through quantitative trait loci (QTL) mapping in unexplored material.\udHere we report the extensive molecular and phenotypic characterization of hundreds of Ethiopian\uddurum wheat landraces and several Ethiopian improved lines. We test 81,587 markers scoring\ud30,155 single nucleotide polymorphisms and use them to survey the diversity, structure, and\udgenome-specific variation in the panel. We show the uniqueness of Ethiopian germplasm using a\udsiding collection of Mediterranean durum wheat accessions. We phenotype the Ethiopian panel\udfor ten agronomic traits in two highly diversified Ethiopian environments for two consecutive\udyears, and use this information to conduct a genome wide association study. We identify several\udloci underpinning agronomic traits of interest, both confirming loci already reported and\uddescribing new promising genomic regions. These loci may be efficiently targeted with\udmolecular markers already available to conduct marker-assisted selection in Ethiopian and\udinternational wheat. We show that Ethiopian durum wheat represents an important and mostly\udunexplored source of durum wheat diversity. The panel analyzed in this study allows the\udaccumulation of QTL mapping experiments, providing the initial step for a quantitative,\udmethodical exploitation of untapped diversity in producing a better wheat.