Association of Agronomic Traits with SNP Markers in Durum Wheat (Triticum turgidum L. durum (Desf.))

AbstractAssociation mapping is a powerful approach to detect associations between traits of interestand genetic markers based on linkage disequilibrium (LD) in molecular plant breeding. Inthis study, 150 accessions of worldwide originated durum wheat germplasm (Triticum turgidumspp. durum) were genotyped using 1,366 SNP markers. The extent of LD on eachchromosome was evaluated. Association of single nucleotide polymorphisms (SNP) markerswith ten agronomic traits measured in four consecutive years was analyzed under a mixlinear model (MLM). Two hundred and one significant association pairs were detected inthe four years. Several markers were associated with one trait, and also some markerswere associated with multiple traits. Some of the associated markers were in agreementwith previous quantitative trait loci (QTL) analyses. The function and homology analyses ofthe corresponding ESTs of some SNP markers could explain many of the associations forplant height, length of main spike, number of spikelets on main spike, grain number perplant, and 1000-grain weight, etc. The SNP associations for the observed traits are generallyclustered in specific chromosome regions of the wheat genome, mainly in 2A, 5A, 6A,7A, 1B, and 6B chromosomes. This study demonstrates that association mapping can complementand enhance previous QTL analyses and provide additional information formarker-assisted selection