Mapping QTLs for Yield Related Traits Using Two Associated RIL Populations of Wheat

The objectives of this study were to map quantitative trait loci (QTLs) for yield related trait in wheat (Triticum aestivum L.) grown in multiple environments, identify chromosomal regions harboring important loci, and validate the stability of these chromosomal regions in different environments. The QTLs for spikelet number per spike (SN), grain number per spike (GN), spike number per plant (PN), 1000-grain weight (GW), and grain yield per plant (GY) were detected using inclusive composite interval mapping method. The 2 mapping populations were the F_8:9 generations of Weimai 8 × Yannong 19 (WY population) and Weimai 8 × Jimai 20 (WJ population), which contained 229 and 485 lines, respectively. Both populations were grown in 4 environments. Numerous QTLs for the 5 traits were identified on 21 chromosomes of wheat, including 9 for SN, 9 for GN, 4 for PN, 7 for GW, and 5 for GY in the WY population and 20 for SN, 16 for GN, 11 for PN, 14 for GW, and 9 for GY in the WJ population. Sixteen and 3 major QTLs with the phenotypic contribution larger than 10% were detected in the WY and WJ populations, respectively. In addition, 5 and 17 QTLs were identified in at least 2 environments in the WY and WJ populations, respectively. Some QTLs were mapped in the same or closely linked marker intervals in both populations. Nine pairs of QTLs and 2 chromosomal regions were inferred to be identical between the 2 populations. These results may enrich the QTL information for yield components of wheat and facilitate marker-assisted selection.