Marker-trait associations of yield related traits in bread wheat (Triticum aestivum L.) under a semi-arid climate

Identifying QTLs (quantitative trait loci) that control yield related traits under a stressed environment is very useful for marker-assisted selection (MAS). Marker-trait associations (MTA) for several agro-morphological traits were performed with 130 Tunisian and exotic spring bread wheat (Triticum aestivum L.) accessions under a semi-arid climate in El Kef, Tunisia. Grain yield and other important traits were evaluated. A population structural analysis identified two sub populations. In total, 29 MTAs were detected at –log P ≥ 3 using an MLM (mixed linear model), and only 5 MTAs with –log P ≥ 4. The locus on chromosome 4A was detected to control the heading date accounting for up to 22% of the trait variance. Two other loci located on chromosomes 3B and 7B were found to be stable during the two cropping seasons and have a pleiotropic effect on the heading date, yield, internodes length and grain per spike. These two regions are candidates for further genetic analysis.