title: High-density molecular characterization and association mapping in Ethiopian durum wheat landraces reveals high diversity and potential for wheat breeding.
abstract: Durum wheat (Triticum turgidum subsp. durum) is a key crop worldwide, and yet, its improvement and adaptation to emerging environmental threats is made difficult by the limited amount of allelic variation included in its elite pool. New allelic diversity may provide novel loci to international crop breeding through quantitative trait loci (QTL) mapping in unexplored material. Here, we report the extensive molecular and phenotypic characterization of hundreds of Ethiopian durum wheat landraces and several Ethiopian improved lines. We test 81 587 markers scoring 30 155 single nucleotide polymorphisms and use them to survey the diversity, structure, and genome-specific variation in the panel. We show the uniqueness of Ethiopian germplasm using a siding collection of Mediterranean durum wheat accessions. We phenotype the Ethiopian panel for ten agronomic traits in two highly diversified Ethiopian environments for two consecutive years and use this information to conduct a genome-wide association study. We identify several loci underpinning agronomic traits of interest, both confirming loci already reported and describing new promising genomic regions. These loci may be efficiently targeted with molecular markers already available to conduct marker-assisted selection in Ethiopian and international wheat. We show that Ethiopian durum wheat represents an important and mostly unexplored source of durum wheat diversity. The panel analysed in this study allows the accumulation of QTL mapping experiments, providing the initial step for a quantitative, methodical exploitation of untapped diversity in producing a better wheat.
authors: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.|Department of Dryland Crop and Horticultural Sciences, Mekelle University, Mekelle, Ethiopia.
authors: Dejene Kassahun
authors: DK
authors: Mengistu
authors: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.|Sirinka Agricultural Research Center, Sirinka, Woldia, Ethiopia.
authors: Yosef Gebrehawaryat
authors: YG
authors: Kidane
authors: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
authors: Marcello
authors: M
authors: Catellani
authors: Department of Agricultural Sciences, University of Bologna, Bologna, Italy.
authors: Elisabetta
authors: E
authors: Frascaroli
authors: Bioversity International, C/O International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia.
authors: Carlo
authors: C
authors: Fadda
authors: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
authors: Mario Enrico
authors: ME
authors: Pè
authors: Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
authors: Matteo
authors: M
authors: Dell'Acqua
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics; D018745:Genome, Plant / Q000235:genetics; D055106:Genome-Wide Association Study; D015810:Linkage Disequilibrium / Q000235:genetics; D000069600:Plant Breeding; D040641:Quantitative Trait Loci / Q000235:genetics; D014908:Triticum / Q000235:genetics* / Q000502:physiology
keywords: Ethiopia; GWAS; Triticum turgidum subsp. durum; linkage disequilibrium; population genetics; quantitative trait loci