Junli Zhang, University of Idaho, Aberdeen, ID, Jianli Chen, 1691S 2700 W, University of Idaho-Moscow, Aberdeen, ID, Chenggen Chu, Heartland Plant Innovations, Manhattan, KS, Robert S. Zemetra, Crop and Soil Science, Oregon State University, Corvallis, OR and Edward J. Souza, Bayer CropScience, Lincoln, NE
Wheat (Triticum aestivum L.) breeding programs strive to increase grain yield (GY), yet, progress is hampered due to quantitative inheritance, low heritability, and confounding environmental effects. In current study, a winter wheat population of 159 recombinant inbred lines (RILs) were evaluated under three field conditions, rain-fed, terminal drought (water stress applied after anthesis), and fully irrigated, with a total of six location-year environments. QTL mapping was conducted for grain yield main effect (G), the genotype x environment interaction (GEI) effect. A total of 24 QTL were associated with G and 15 QTL associated with GEI, of which 11 QTL were mapped in the flanking chromosomal regions of GY main effect QTL. One QTL Q.Gy.ui-1B.3 was associated with GY in all 6 individual environments and the GY data combined based on field conditions. Significant QTL x environment interaction (QEI), QTL x QTL interaction (QQI) and QTL x QTL x environment (QQEI) were also identified. Present study showed that the QEI and QQI were as important as the main effect of GY QTL, and they should be taken into consideration in the future studies and the marker assisted selection (MAS).