Abstract: 【Objective】 The objective of this study is to reveal the genetic relationship between grain yield (GY) and plant height (PH) and the influence of PH on GY at the QTL level, and provide references for the selection of PH in wheat high yield breeding programs.【Method】Two high density genetic linkage maps were constructed using two associated recombinant inbred lines (RIL) derived from crosses of Weimai8/Yannong19 (hereafter WY) and Weimai8/Jimai20 (hereafter WJ), consisting of 229 and 485 lines, respectively. Both GY and PH of the three parents and the RIL populations were measured in 2009 and 2010 in Tai’an and Zaozhuang. Unconditional and conditional QTL analyse were conducted to detect the genetic relationship between GY and PH, and the QTL effect without the influence of PH. In addition, the effect of population size on the accuracy of QTL detection was discussed. 【Result】In the WY population, 5 and 15 QTLs were detected for GY and PH, respectively, of which totally 8 QTLs explained >10% phenotypic variation (PVE), 3 QTLs were pleiotropy which determined both GY and PH. For GY conditioned on PH, 3 QTLs affecting GY were detected independent of PH, two were totally or partial contributed to PH, and one completely suppressed by PH. In WJ, 7 and 11 QTLs were detected for GY and PH, respectively. One QTL was a major gene affecting PH with additive effect of 8.82 cm, explaining 20.68% of PVE. Conditioned GY on PH, 5 QTLs were identified independent of PH and two were totally due to PH. The QTL effect of the large population WJ was smaller than that of WY, while the LOD scores were higher.【Conclusion】The genetic relationship between GY and PH is contributed and coordinated by various factors, including closely linked or pleiotropy, the contribution or suppression of PH to GY, environmental factors and the interactions between traits, etc. The selection of PH in high yield breeding programs should refer to different genetic backgrounds and ecological environments. A population of large size can detect QTLs more accurate than small ones in QTL mapping.

Key words: Keywords: Wheat, Plant height, Grain yield, Conditional QTL analysis, Genetic relationship