QTL mapping for agronomic traits in Agropyron Gaertn. CP population at the flowering stage

Flowering regulation is a reflection of plant self-adaptation to the environment and is the main determinant of plant yield. The quantitative trait loci (QTL) mapping of agronomic traits associated with the flowering stage of Agropyron Gaertn. was conducted using a cross-pollinated (CP) hybrid population with a total of 113 plant lines between A. mongolicum Keng Z2098 and A. cristatum (L.) Gaertn. Z1842 under four different environmental conditions and the genetic map constructed of 1,023 single-nucleotide polymorphism (SNP) markers. The results showed that 28 QTLs were detected on seven linkage groups. Each QTL explained 0.39–18.46% of the phenotypic variation, with a logarithm of odds (LOD) value ranging from 2.52 to 30.51. Specifically, QTLs were identified for various characteristics: one QTL identified for tiller number (TN), two for plant height (PH), three for days-to-flowering (DTF), five for flag leaf length (FLL), three for flag leaf width (FLW), three for spike length (SL), eight for spike width (SW), one for spikelet number per spike (SNS), and two for flower number per spike (FNS). One stable QTL controlling the SW was detected in two environments at the same loci and was located at 26 cM (Marker29867–Marker26864) on chromosome 5, showing a positive genetic effect. The two QTL enrichment regions suggested that the QTLs might contribute to trait correlation or pleiotropic genes. The identified QTLs potentially offer utility for marker-assisted breeding selection.