Identification and QTL mapping of physiological drivers of soybean yield under contrasting management systems using high-throughput phenotyping

Rapid characterization of physiological traits driving yield are becoming desirable aides to breeding programs to increase the rate of genetic gain. Each chapter in this dissertation investigates areas related to high-throughput phenotyping and physiological traits driving soybean yield. Chapter two seeks to understand the response of diverse soybean germplasm to seeding rate. An evaluation of final plot seed yield, seed protein percentage, seed oil percentage, seed weight, height, maturity, and plant lodging revealed a significant genotype x seeding rate interaction only for lodging, suggesting current soybean germplasm and soybean of wide genetic ancestry respond similarly to seeding rate. Our second objective was to identify physiological traits at multiple growth stages predicting yield response under contrasting levels of seeding rate. Adaptive elastic net models characterized diverging traits between seeding rates and determined chlorophyll traits as the leading predictors across seeding rates. Chapter three quantifies biomass partitioning strategies and residue quality determined through carbon:nitrogen (C:N) ratios in the same diverse panel of SoyNAM genotypes in Chapter 2. Above-ground plant components were dissected at three reproductive stages and revealed significant differences in biomass partitioning by R4. Significant genetic variation in C:N residue quality was found with no apparent negative relationship to final grain yield. Optimal biomass partitioning strategies for yield and improved residue C:N ratios for whole-system nitrogen sustainability can be targeted for yield improvement. Lastly, chapter four includes a QTL mapping study of vegetative indices used for yield prediction in Chapter 1 in four SoyNAM RIL populations derived from five of the 32 parent NAM genotypes evaluated in Chapters 1 and 2. Five QTL were detected for grain yield and vegetative indices NDVI, NMDI, NWIB, PSRI, and VREI2 measured at R5, spanning chromosomes 1, 3, 10 and 18. These QTL can serve as aides to MAS in soybean breeding and inform future studies aimed at dissecting the physiology of soybean grain yield. The overall research provides insights on soybean biomass partitioning and evidence of the presence of genetic variation in residue traits; physiological traits to predict yield in diverse germplasm and row-density management systems; and genomic regions mapped to spectral wavelengths related to soybean seed yield

Genetic dissection of sorghum height and maturity variation using sorghum converted lines and their exotic progenitors

Sorghum is a photoperiod-sensitive, short-day tropical species that shows long delays in flowering at temperate latitudes. Most temperate-adapted sorghum cultivars are photoperiod-insensitive and dwarfed for grain production. Classical segregation studies predict that temperate adaptedness involves four major loci each for maturity and dwarfing. Two major maturity loci, Ma1 (PRR37) and Ma3 (phytochrome B), and a single major dwarfing locus, Dw3 (PGP1/br2), have been cloned. Sorghum conversion (SC) lines are exotic varieties that have been introgressed with early maturity and dwarfing QTL from a common, temperate-adapted donor using a minimum of four backcrosses. In this study partially-isogenic populations were generated by crossing six diverse SC lines to their corresponding exotic progenitor (EP) lines to assess the phenotypic effects of individual introgressions from the temperate-adapted donor. Initial genotyping results revealed one of the six populations resulted from an outcross. In summer 2012, 192 F3 lines from the five remaining populations were phenotyped for plant height and maturity. Subsets of 109-175 F3 lines were genotyped using Illumina genotyping-by-sequencing (GBS) and used for QTL analysis. QTL models explained 62.31-88.16% of the phenotypic variation for height and maturity in these partially isogenic populations. Nearly all variation was accounted for by the linked Ma1/Dw2 loci on chromosome 6 and the Dw3 and Dw1 loci on chromosomes 7 and 9 respectively. The Dw1 locus fractionated into linked QTL for height and maturity, and a novel height QTL on chromosome 3 was discovered. Evidence is presented for multiple functionally distinct alleles at Ma1, and for large differences in recombination rate among populations on chromosome 6. Candidate genes underlying QTL for Dw2, Dw1, and the new Dw1-linked maturity locus on chromosome 9 are discussed

Enhancing first year management students’ engagement: an action research project to explore the use of the Essay Feedback Checklist (EFC)

Feedback represents one of the key factors that affect student learning. A question is raised here as to what extent engaging students with feedback and considering their voices as partners in the assessment process can improve their confidence and therefore their learning. The objective of this action research was to support the introduction of the Essay Feedback Checklist (EFC) to first year management students at a British University. This research examined the use of EFC as an interactive two-way communication tool between tutors and students. The research also aimed to help management students to be more aware of the assessment criteria thus to be more engaged in feedback. Data was collected from students and tutors before and after the use of the EFC in order to highlight their perspectives regarding the effective use of the tool. The research's findings argued that students found the EFC useful to support engagement with the feedback and in improving their confidence through receiving quality feedback to develop their work further. Tutors and students claimed that the EFC created an interactive environment in providing feedback and it helped to open a dialogue about it, but they also highlighted some drawbacks

Deploying Fourier Coefficients to Unravel Soybean Canopy Diversity

Soybean canopy outline is an important trait used to understand light interception ability, canopy closure rates, row spacing response, which in turn affects crop growth and yield, and directly impacts weed species germination and emergence. In this manuscript, we utilize a methodology that constructs geometric measures of the soybean canopy outline from digital images of canopies, allowing visualization of the genetic diversity as well as a rigorous quantification of shape parameters. Our choice of data analysis approach is partially dictated by the need to efficiently store and analyze large datasets, especially in the context of planned high-throughput phenotyping experiments to capture time evolution of canopy outline which will produce very large datasets. Using the Elliptical Fourier Transformation (EFT) and Fourier Descriptors (EFD), canopy outlines of 446 soybean plant introduction (PI) lines from 25 different countries exhibiting a wide variety of maturity, seed weight, and stem termination were investigated in a field experiment planted as a randomized complete block design with up to four replications. Canopy outlines were extracted from digital images, and subsequently chain coded, and expanded into a shape spectrum by obtaining the Fourier coefficients/descriptors. These coefficients successfully reconstruct the canopy outline, and were used to measure traditional morphometric traits. Highest phenotypic diversity was observed for roundness, while solidity showed the lowest diversity across all countries. Some PI lines had extraordinary shape diversity in solidity. For interpretation and visualization of the complexity in shape, Principal Component Analysis (PCA) was performed on the EFD. PI lines were grouped in terms of origins, maturity index, seed weight, and stem termination index. No significant pattern or similarity was observed among the groups; although interestingly when genetic marker data was used for the PCA, patterns similar to canopy outline traits was observed for origins, and maturity indexes. These results indicate the usefulness of EFT method for reconstruction and study of canopy morphometric traits, and provides opportunities for data reduction of large images for ease in future use

People with learning disabilities and ‘active ageing’

Background: People (with and without learning disabilities) are living longer. Demographic ageing creates challenges and the leading policy response to these challenges is ‘active ageing’. ‘Active’ does not just refer to the ability to be physically and economically active, but also includes ongoing social and civic engagement in the communities of which older people are a part. Active ageing should apply to all citizens, including the experiences of older people with learning disabilities. Materials and Methods: This literature based paper explores the focus of active ageing discussions in relation to the general population drawing comparisons with the experiences of older people with learning disabilities. Results: It points out that older people with learning disabilities and their experiences are largely missing from broader policy discussions of active ageing. Conclusion: The paper concludes by arguing for inclusive research in active ageing which takes account of the concerns and interests of older people with learning disabilities

Identification and QTL mapping of physiological drivers of soybean yield under contrasting management systems using high-throughput phenotyping

Rapid characterization of physiological traits driving yield are becoming desirable aides to breeding programs to increase the rate of genetic gain. Each chapter in this dissertation investigates areas related to high-throughput phenotyping and physiological traits driving soybean yield. Chapter two seeks to understand the response of diverse soybean germplasm to seeding rate. An evaluation of final plot seed yield, seed protein percentage, seed oil percentage, seed weight, height, maturity, and plant lodging revealed a significant genotype x seeding rate interaction only for lodging, suggesting current soybean germplasm and soybean of wide genetic ancestry respond similarly to seeding rate. Our second objective was to identify physiological traits at multiple growth stages predicting yield response under contrasting levels of seeding rate. Adaptive elastic net models characterized diverging traits between seeding rates and determined chlorophyll traits as the leading predictors across seeding rates. Chapter three quantifies biomass partitioning strategies and residue quality determined through carbon:nitrogen (C:N) ratios in the same diverse panel of SoyNAM genotypes in Chapter 2. Above-ground plant components were dissected at three reproductive stages and revealed significant differences in biomass partitioning by R4. Significant genetic variation in C:N residue quality was found with no apparent negative relationship to final grain yield. Optimal biomass partitioning strategies for yield and improved residue C:N ratios for whole-system nitrogen sustainability can be targeted for yield improvement. Lastly, chapter four includes a QTL mapping study of vegetative indices used for yield prediction in Chapter 1 in four SoyNAM RIL populations derived from five of the 32 parent NAM genotypes evaluated in Chapters 1 and 2. Five QTL were detected for grain yield and vegetative indices NDVI, NMDI, NWIB, PSRI, and VREI2 measured at R5, spanning chromosomes 1, 3, 10 and 18. These QTL can serve as aides to MAS in soybean breeding and inform future studies aimed at dissecting the physiology of soybean grain yield. The overall research provides insights on soybean biomass partitioning and evidence of the presence of genetic variation in residue traits; physiological traits to predict yield in diverse germplasm and row-density management systems; and genomic regions mapped to spectral wavelengths related to soybean seed yield.</p

500 ICT Tips for Primary Teachers

Information and Communications Technology (ICT) has been the focus of much debate and development within education, especially in the primary sector. This text offers tried and tested ideas for using IT effectively across the whole primary curriculum

500 ICT Tips for Primary Teachers

Information and Communications Technology (ICT) has been the focus of much debate and development within education, especially in the primary sector. This text offers tried and tested ideas for using IT effectively across the whole primary curriculum