Incorporating pleiotropic quantitative trait loci in dissection of complex traits: seed yield in rapeseed as an example

© The Author(s) 2017 This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International License http://creativecommons.org/licenses/by/4.0/), which permits use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Most agronomic traits of interest for crop improvement (including seed yield) are highly complex quantitative traits controlled by numerous genetic loci, which brings challenges for comprehensively capturing associated markers/ genes. We propose that multiple trait interactions underlie complex traits such as seed yield, and that considering these component traits and their interactions can dissect individual quantitative trait loci (QTL) effects more effectively and improve yield predictions. Using a segregating rapeseed (Brassica napus) population, we analyzed a large set of trait data generated in 19 independent experiments to investigate correlations between seed yield and other complex traits, and further identified QTL in this population with a SNP-based genetic bin map. A total of 1904 consensus QTL accounting for 22 traits, including 80 QTL directly affecting seed yield, were anchored to the B. napus reference sequence. Through trait association analysis and QTL meta-analysis, we identified a total of 525 indivisible QTL that either directly or indirectly contributed to seed yield, of which 295 QTL were detected across multiple environments. A majority (81.5%) of the 525 QTL were pleiotropic. By considering associations between traits, we identified 25 yield-related QTL previously ignored due to contrasting genetic effects, as well as 31 QTL with minor complementary effects. Implementation of the 525 QTL in genomic prediction models improved seed yield prediction accuracy. Dissecting the genetic and phenotypic interrelationships underlying complex quantitative traits using this method will provide valuable insights for genomics-based crop improvement.Peer reviewedFinal Published versio

Anatase TiO2 Activated by Gold Nanoparticles for Selective Hydrodeoxygenation of Guaiacol to Phenolics

Gold nanoparticles on a number of supporting materials, including anatase TiO2 (TiO2-A, in 40 nm and 45 pm), rutile TiO2 (TiO2-R), ZrO2, Al2O3, SiO2, and activated carbon, were evaluated for hydrodeoxygenation of guaiacol in 6.5 MPa initial H-2 pressure at 300 degrees C. The presence of gold nanoparticles on the supports did not show distinguishable performance compared to that of the supports alone in the conversion level and in the product distribution, except for that on a TiO2-A-40 nm. The lack of marked catalytic activity on supports other than TiO2-A-40 nm suggests that Au nanoparticles are not catalytically active on these supports. Most strikingly, the gold nanoparticles on the least-active TiO2-A-40 nm support stood out as the best catalyst exhibiting high activity with excellent stability and remarkable selectivity to phenolics from guaiacol hydrodeoxygenation. The conversion of guaiacol (similar to 43.1%) over gold on the TiO2-A-40 nm was about 33 times that (1.3%) over the TiO2-A-40 nm alone. The selectivity of phenolics was 87.1%. The products are mainly phenolic compounds with no aromatics and saturated hydrocarbons such as cyclohexane. The gold particle size ranging from 2.7 to 41 nm and water content were found to significantly affect the Au/TiO2-A-40 nm catalyst activity but not the product selectivity. The reaction rates of 0.26 and 0.91 (min(-1) g-cat(-1) cm(3)) were determined for guaiacol hydrogenation and catechol hydrogenation, respectively. Bimolecular methylation was established as the dominant mechanism for methyl group transfer among the phenolics. Two major pathways of guaiacol hydrogenation to phenolics over the 0.4Au-19 nm/TiO2-A-40 nm are proposed: (1) direct hydrogenation of guaiacol to form phenol and methanol, (2) hydrodehydroxylation of catechol intermediate from the transmethylation between guaiacol and phenol

Anatase TiO₂ Activated by Gold Nanoparticles for Selective Hydrodeoxygenation of Guaiacol to Phenolics

Gold nanoparticles on a number of supporting materials, including anatase TiO₂ (TiO₂-A, in 40 nm and 45 μm), rutile TiO₂ (TiO₂-R), ZrO₂, Al₂O₃, SiO₂ , and activated carbon, were evaluated for hydrodeoxygenation of guaiacol in 6.5 MPa initial H₂ pressure at 300 °C. The presence of gold nanoparticles on the supports did not show distinguishable performance compared to that of the supports alone in the conversion level and in the product distribution, except for that on a TiO₂-A-40 nm. The lack of marked catalytic activity on supports other than TiO₂-A-40 nm suggests that Au nanoparticles are not catalytically active on these supports. Most strikingly, the gold nanoparticles on the least-active TiO₂-A-40 nm support stood out as the best catalyst exhibiting high activity with excellent stability and remarkable selectivity to phenolics from guaiacol hydrodeoxygenation. The conversion of guaiacol (∼43.1%) over gold on the TiO₂-A-40 nm was about 33 times that (1.3%) over the TiO₂-A-40 nm alone. The selectivity of phenolics was 87.1%. The products are mainly phenolic compounds with no aromatics and saturated hydrocarbons such as cyclohexane. The gold particle size ranging from 2.7 to 41 nm and water content were found to significantly affect the Au/TiO₂-A-40 nm catalyst activity but not the product selectivity. The reaction rates of 0.26 and 0.91 (min^–1 g-cat^–1 cm³) were determined for guaiacol hydrogenation and catechol hydrogenation, respectively. Bimolecular methylation was established as the dominant mechanism for methyl group transfer among the phenolics. Two major pathways of guaiacol hydrogenation to phenolics over the 0.4Au-19 nm/TiO₂-A-40 nm are proposed: (1) direct hydrogenation of guaiacol to form phenol and methanol, (2) hydrodehydroxylation of catechol intermediate from the transmethylation between guaiacol and phenol