QTL Mapping Of Quality Traits In Synthetic Hexaploid Wheat

Wheat is an important protein for humans (about 38.4% of total grain protein). The wheat yield and quality is directly related to the satisfaction of human food and the production level, and is impact on human nutrition balance. Therefore, it is meaningful to understanding the genetic effects of wheat quality and its QTL localization. In this study,171 recombinant inbred lines (RILs), which were obtained by crossed from synthetic hexaploid wheat SHW-L1 and "Chuanmai32", were used to construct genetic map. And then, the quantitative trait locus (QTLs) controlled the main quality traits (the grain protein content, sedimentation value, farinograph parameters, and so on) and the pre-harvest sprouting were detected. The main results were described as following:1. The the main quality traits and the pre-harvest sprouting were evaluated in 171 lines. The results indicate that the grain protein content of SHW-L1 ware significantly higher than "Chuanmai32"; a larger coefficient of variation (CV) of the RILs ware be found, the RILs showed a continuous distribution and have super-pro-type. That traits ware quantitative traits controlled by multiple genes, suitable for QTL analysis.2. On quality traits correlation analysis, grain protein content (GPC) had a significant positive correlation with dry gluten (DG), wet gluten (WG), water absorption (WB) and mixing tolerance index (MTI), but had a significant negative correlation with the sedimentation value; dry gluten and wet gluten only with grain protein content had relevant relationship, while no correlation with the others. Other traits (sedimentation value (SV), gluten index (GI), development time (DT), Stability stability time (ST), time to breakdown (BT), farinograph quality number (FQN)) were significant or highly significant related.3. QTL analysis of the quality traits and the pre-harvest sprouting showed that 14 additive QTLs were detected. These QTLs were located in the 1B,2D,4A,5A,5D, 6D and 7D, and the contribution rate ware between 10.82-50.53%. For grain protein content, four QTLs were located on chromosomes 5A,5D,7D and 4A, between the markers wmc524 and gwm304, gwm212 and gdml53, cfa2040 and gpw4358, dupwlO8 and cau2, explained 18.34%,23.80%,23.54%,20.35% of the phenotypic variation, respectively. For sedimentation value, one QTL was located on chromosome 2B between the markers wmc770 and gpw4132, which explained 17.01% of the total phenotypic variation. For wet gluten, one QTL was located on chromosome 7D between the markers gdm99 and gpw7659, which explained 13.03% of the total phenotypic variation. For water absorption, two QTLs were located on chromosome 6D betweent the markers wmc748 and barc204, cfd47 and cfdl88, explained 13.43%,13.17% of the phenotypic variation. For stability time, two QTLs was located on chromosome 1B betweent the markers barc120 and gpw7603, gpw7422 and cfd65, explained 13.43%,13.17% of the total phenotypic variation, respectively. For mixing tolerance index,3 QTLs was located on chromosomes 1B and 2D, the two QTLs which was located on chromosome 1B was at the same location with the QTLs for stability time. For the pre-harvest sprouting, one QTL was located on chromosome 2D betweent the markers gpw4473 and gpw332a, explained 50.53% of the phenotypic variation.