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Local adaptation and genotype by environment (G×E) interactions affect the expression of phenotypes in crop species. An investigation on the interplay between adaptation and G×E on sorghum heterosis phenotypes is lacking. To address this question, a set of 112 diverse grain sorghum hybrids and their 22 inbred parents of local and exotic origins, representing the primary female and male heterotic groups, were tested in five contrasting sorghum growing environments across two years in Queensland, Australia. Plant height, days to flowering, seed yield, grain weight, and grain number were measured and used in the estimation of heterosis. Mid parent heterosis for yield ranged from -25 to 217% and was highly influenced by grain number. In contrast to observations in maize the magnitude of heterosis for yield was not associated with site mean. Striking differences were observed in heterosis in hybrids from locally developed inbred parents compared with hybrids that were developed from exotic inbred parents developed in other countries. Heterosis in the latter combination was higher on average across all the test environments for the majority of traits. We hypothesise maladaptive phenotypic plasticity in the exotic parents contributed to the observed differences in heterosis estimates. These data confirm that heterosis estimates in sorghum must be obtained and interpreted in relevant genetic and environmental contexts. Breeders in developing countries with low sorghum hybrid seed uptake will find these insights useful when selecting hybrids for broader adaptation, improving efficiency of their breeding programs. This article is protected by copyright. All rights reserved

The economic return for peanut (Arachis hypogaea L.) in Ghana is often low due to limitations in the availability of inputs or their adoption, which are needed to optimize yield. Six experiments were conducted in Ghana in 2020 and 2021 to determine the impact of planting date, cultivar, fertilization, pest management practices, and harvest date on peanut yield, financial return, and pest reaction. A wide range of interactions among these treatment factors were often observed for infestations of aphids (Aphis gossypii Glover); groundnut rosette disease (Umbravirus: Tombusviridaee); millipedes (Peridontopyge spp.); white grubs (Schyzonicha spp.); wireworms (Conoderus spp.); termites (Microtermes and Odontotermes spp.); canopy defoliation as a result of early leaf spot disease caused by Passalora arachidicola (Hori) and late leaf spot caused by Nothopassalora personata (Berk. and M. A. Curtis); and the scarification and boring of pods caused by arthropod feeding. Pod yield and economic return increased for the cultivar Chitaochi and Sarinut 2 when fertilizer was applied and when fertilizer was applied at early, mid-, and late planting dates. Pod yield and economic return increased when a combination of locally derived potassium soaps was used for aphid suppression and one additional hand weeding was used in the improved pest management practice compared with the traditional practice without these inputs. Pearson correlations for yield and economic return were negatively correlated for all pests and damage caused by pests. The results from these experiments can be used by farmers and their advisors to develop production packages for peanut production in Ghana.

Sustaining crop productivity and resilience in water-limited environments and under rising temperatures are matters of concern worldwide. We investigated the leaf anatomical traits that underpin our recently identified link between leaf width (LW) and intrinsic water use efficiency (iWUE), as traits of interest in plant breeding. Ten sorghum lines with varying LW were grown under three temperatures to expand the range of variation of both LW and gas exchange rates. Leaf gas exchange, surface morphology and cross-sectional anatomy were measured and analysed using structural equations modelling. Narrower leaves had lower stomatal conductance (gs ) and higher iWUE across growth temperatures. They also had smaller intercellular airspaces, stomatal size, percentage of open stomatal aperture relative to maximum, hydraulic pathway, mesophyll thickness, and leaf mass per area. Structural modelling revealed a developmental association among leaf anatomical traits that underpinned gs variation in sorghum. Growing temperature and LW both impacted leaf gas exchange rates, but only LW directly impacted leaf anatomy. Wider leaves may be more productive under well-watered conditions, but consume more water for growth and development, which is detrimental under water stress.

Mitochondria are organelles within eukaryotic cells that are central to the metabolic processes of cellular respiration and ATP production. However, the evolution of mitochondrial genomes (mitogenomes) in plants is virtually unknown compared to animal mitogenomes or plant plastids, due to complex structural variation and long stretches of repetitive DNA making accurate genome assembly more challenging. Comparing the structural and sequence differences of organellar genomes within and between sorghum species is an essential step in understanding evolutionary processes such as organellar sequence transfer to the nuclear genome as well as improving agronomic traits in sorghum related to cellular metabolism.

Sustaining crop productivity and resilience in water-limited environments and under rising temperatures are matters of concern worldwide. We investigated the leaf anatomical traits that underpin our recently identified link between leaf width (LW) and intrinsic water use efficiency (iWUE), as traits of interest in plant breeding. Ten sorghum lines with varying LW were grown under three temperatures to expand the range of variation of both LW and gas exchange rates. Leaf gas exchange, surface morphology and cross-sectional anatomy were measured and analysed using structural equations modelling. Narrower leaves had lower stomatal conductance (gs) and higher iWUE across growth temperatures. They also had smaller intercellular airspaces, stomatal size, percentage of open stomatal aperture relative to maximum, hydraulic pathway, mesophyll thickness, and leaf mass per area. Structural modelling revealed a developmental association among leaf anatomical traits that underpinned gs variation in sorghum. Growing temperature and LW both impacted leaf gas exchange rates, but only LW directly impacted leaf anatomy. Wider leaves may be more productive under well-watered conditions, but consume more water for growth and development, which is detrimental under water stress.

This study quantified genetic variation in root system architecture (root number, angle, length and dry mass) within a diversity panel of 1771 Ethiopian sorghum landraces and identified 22 genomic regions associated with the root variations.

Expanding upon the material delivered during the LMS Autumn Algebra School 2020, this volume reflects the fruitful connections between different aspects of representation theory. Each survey article addresses a specific subject from a modern angle, beginning with an exploration of the representation theory of associative algebras, followed by the coverage of important developments in Lie theory in the past two decades, before the final sections introduce the reader to three strikingly different aspects of group theory. Written at a level suitable for graduate students and researchers in related fields, this book provides pure mathematicians with a springboard into the vast and growing literature in each area.

Since the advent of the standardized movement in education, there has been a plethora of research pertaining to the characteristics of successful schools. Even more so, studies have consistently been trying to investigate if there is a proverbial gold standard of what encompasses successful school improvement in low-income communities serving minority students. Complementary to this endeavor, types of school leadership have also been examined to see if there are common trends and themes for school leaders within the studied communities. In the past thirty years, three leadership types have been marked as influential: instructional, transformational, and distributed leadership. This mixed-methods case study attempted to look at these leadership types in an interconnected fashion, by amalgamating instructional and transformational leadership as one construct (i.e., integrated leadership; Marks & Printy, 2003) and using distributed leadership as a process variable—thus showcasing how distributed leadership actualizes an integrated leadership model. Two high-performing elementary schools in New York City, residing in predominately low-income minority communities, were purposely selected. Using a reconceptualized survey, the Distributed Integrated Leadership Survey (DILS), as well as qualitative factors (i.e., open-ended responses, public records), this study had the following overarching goals: to investigate the degree to which integrated and distributed leadership manifest within the studied schools and to gauge the relationship between distributed leadership and an integrated model. Quantitative and qualitative results from this study elicited that successful school leadership is not a monolithic construct, but rather an amalgamation of motivational, instructional, and distributed factors.

The following dissertation discusses the development of Selectfluor mediated Minisci reactions leading to functionalized heterocycles and quinones. These investigations include a wide variety of heterocycles and quinones that can be functionalized in one step allowing for access to more complex structures while retaining the essential backbone. Mechanistic investigations and direct comparisons to other harsher oxidants are considered. Novel transnitrosating reagents were developed allowing for nitroso compounds in one step when thermally initiated. Considerations for other applications for this novel reagent are discussed as well.

Developing sorghum genotypes adapted to different light environments requires understanding of a plant’s ability to capture light, determined through leaf angle specifically. This study dissected the genetic basis of leaf angle in three-year field trials at two sites, using a sorghum diversity panel (729 accessions). A wide range of variation in leaf angle with medium heritability was observed. Leaf angle explained 36% variation in canopy light extinction coefficient, highlighting the extent to which variation in leaf angle influences light interception at whole canopy level. This study also found the sorghum races of Guinea and Durra consistently having the largest and smallest leaf angle, respectively, highlighting the potential role of leaf angle in adaptation to distinct environments. The genome-wide association study detected 33 QTL associated with leaf angle. Strong synteny was observed with previously detected leaf angle QTL in maize (70%) and rice (40%) within 10 cM, among which the overlap was significantly enriched according to Chi-square tests, suggesting a highly consistent genetic control in grasses. A priori leaf angle candidate genes identified in maize and rice were found to be enriched within a 1-cM window around the sorghum leaf angle QTL. Additionally, protein domain analysis identified the WD40 protein domain as being enriched within a 1-cM window around the QTL. These outcomes show that there is sufficient heritability and natural variation in the angle of upper leaves in sorghum which may be exploited to change light interception and optimise crop canopies for different contexts.

In cereal crops, average leaf angle of the canopy affects the total amount of radiation that is intercepted and how effectively light is distributed through the canopy. Selecting for more erect leaves in maize and rice has allowed higher density plantings and has been associated with significant productivity gains in those crops. The effects of leaf angle on crop productivity depend on how it influences within-canopy light distribution and the plants’ efficiency in using that light to produce biomass. Canopy light distribution is influenced by agronomic interventions such as growing at different locations, sowing on different dates, using different plant densities (leaf area index). For sorghum, which may be grown across a large range of latitudes and plant population densities, the effects of leaf angle manipulations have not previously been studied. We used the APSIM-DCaPST sorghum model to simulate the effects of more erectophile canopies on yield for two locations with different latitudes and planting dates, assuming low-and high- intensity agronomies. The simulations showed that more erect leaves would result in yield benefits in most years at both of those locations. Contrary to the situation in maize, the simulated yield gains were greatest in the low-yielding rather than the high-yielding years. Interestingly also, the simulated productivity gains in erectophile sorghum canopies were not due to enhanced light penetration as suggested in maize, but rather through effects on extent of radiation interception and its implications for early crop growth and crop water balance through the crop life cycle.

Sorghum, a genetically diverse C(4) cereal, is an ideal model to study natural variation in photosynthetic capacity. Specific leaf nitrogen (SLN) and leaf mass per leaf area (LMA), as well as, maximal rates of Rubisco carboxylation (V (cmax)), phosphoenolpyruvate (PEP) carboxylation (V (pmax)), and electron transport (J (max)), quantified using a C(4) photosynthesis model, were evaluated in two field-grown training sets (n = 169 plots including 124 genotypes) in 2019 and 2020. Partial least square regression (PLSR) was used to predict V (cmax) (R (2) = 0.83), V (pmax) (R (2) = 0.93), J (max) (R (2) = 0.76), SLN (R (2) = 0.82), and LMA (R (2) = 0.68) from tractor-based hyperspectral sensing. Further assessments of the capability of the PLSR models for V (cmax), V (pmax), J (max), SLN, and LMA were conducted by extrapolating these models to two trials of genome-wide association studies adjacent to the training sets in 2019 (n = 875 plots including 650 genotypes) and 2020 (n = 912 plots with 634 genotypes). The predicted traits showed medium to high heritability and genome-wide association studies using the predicted values identified four QTL for V (cmax) and two QTL for J (max). Candidate genes within 200 kb of the V (cmax) QTL were involved in nitrogen storage, which is closely associated with Rubisco, while not directly associated with Rubisco activity per se. J (max) QTL was enriched for candidate genes involved in electron transport. These outcomes suggest the methods here are of great promise to effectively screen large germplasm collections for enhanced photosynthetic capacity.

DNA methylation is a chromatin modification that plays an essential role in regulatinggene expression and genome stability and it is typically associated with gene silencingand heterochromatin. Owing to its heritability, alterations in the patterns of DNA methyla-tion have the potential to provide for epigenetic inheritance of traits. Contemporary epige-nomic technologies provide information beyond sequence variation and could supplyalternative sources of trait variation for improvement in crops such as sorghum. Yet, com-pared with other species such as maize and rice, the sorghum DNA methylome is farless well understood. The distribution of CG, CHG, and CHH methylation in the genomeis different compared with other species. CG and CHG methylation levels peak aroundcentromeric segments in the sorghum genome and are far more depleted in the genedense chromosome arms. The genes regulating DNA methylation in sorghum are also yetto be functionally characterised; better understanding of their identity and functional ana-lysis of DNA methylation machinery mutants in diverse genotypes will be important tobetter characterise the sorghum methylome. Here, we catalogue homologous genesencoding methylation regulatory enzymes in sorghum based on genes inArabidopsis,maize, and rice. Discovering variation in the methylome may uncover epialleles thatprovide extra information to explain trait variation and has the potential to be applied inepigenome-wide association studies or genomic prediction. DNA methylation can alsoimprove genome annotations and discover regulatory elements underlying traits. Thus,improving our knowledge of the sorghum methylome can enhance our understanding ofthe molecular basis of traits and may be useful to improve sorghum performance.

The stay-green trait is recognised as a key drought adaptation mechanism in cereals worldwide. Stay-green sorghum plants exhibit delayed senescence of leaves and stems, leading to prolonged growth, a reduced risk of lodging and higher grain yield under end-of-season drought stress. More than 45 quantitative trait loci (QTL) associated with stay-green have been identified, including two major QTL (Stg1 and Stg2). However, none of the contributing genes that regulate functional stay-green are known. Here we show that the PIN FORMED family of auxin efflux carriers induce some of the causal mechanisms driving the stay-green phenotype in sorghum, with SbPIN4 and SbPIN2 located in Stg1 and Stg2, respectively. We found that 9 of 11 sorghum PIN genes aligned with known stay-green QTL. In transgenic studies, we demonstrated that PIN genes located within the Stg1 (SbPIN4), Stg2 (SbPIN2) and Stg3b (SbPIN1) QTL regions acted pleiotropically to modulate canopy development, root architecture and panicle growth in sorghum, with SbPIN1, SbPIN2 and SbPIN4 differentially expressed in various organs relative to the non stay-green control. The emergent consequence of such modifications in canopy and root architecture is a stay-green phenotype. Crop simulation modelling shows that the SbPIN2 phenotype can increase grain yield under drought.

Leaf width was correlated with plant-level transpiration efficiency and associated with 19 QTL in sorghum, suggesting it could be a surrogate for transpiration efficiency in large breeding program. Enhancing plant transpiration efficiency (TE) by reducing transpiration without compromising photosynthesis and yield is a desirable selection target in crop improvement programs. While narrow individual leaf width has been correlated with greater intrinsic water use efficiency in C4 species, the extent to which this translates to greater plant TE has not been investigated. The aims of this study were to evaluate the correlation of leaf width with TE at the whole-plant scale and investigate the genetic control of leaf width in sorghum. Two lysimetry experiments using 16 genotypes varying for stomatal conductance and three field trials using a large sorghum diversity panel (n = 701 lines) were conducted. Negative associations of leaf width with plant TE were found in the lysimetry experiments, suggesting narrow leaves may result in reduced plant transpiration without trade-offs in biomass accumulation. A wide range in width of the largest leaf was found in the sorghum diversity panel with consistent ranking among sorghum races, suggesting that environmental adaptation may have a role in modifying leaf width. Nineteen QTL were identified by genome-wide association studies on leaf width adjusted for flowering time. The QTL identified showed high levels of correspondence with those in maize and rice, suggesting similarities in the genetic control of leaf width across cereals. Three a priori candidate genes for leaf width, previously found to regulate dorsoventrality, were identified based on a 1-cM threshold. This study provides useful physiological and genetic insights for potential manipulation of leaf width to improve plant adaptation to diverse environments.

The efficiency with which sorghum crops use intercepted radiation (RUE) affects their maximum productivity. RUE in turn, is affected by crop canopy characteristics, as well as leaf biochemical parameters determining maximum leaf photosynthetic rates. These traits are notoriously slow to measure and have previously not been amenable to selection in breeding programs. We used hyperspectral sensors attached to a tractor to estimate leaf and canopy traits associated with RUE in large sorghum field trials. Using Partial Least Square Regression we developed models to predict leaf biochemical photosynthetic parameters known to limit C4 photosynthesis, such as maximum Rubisco and PEP carboxylation rates (Vcmax and Vpmax, respectively) and maximum electron transport rate (Jmax) from the canopy hyperspectral reflectance. We also used various vegetation indices to predict canopy characteristics such as light interception and biomass which allowed us to calculate canopy radiation use efficiency for each trial plot. This is the first time that parameters related to photosynthetic efficiency in sorghum have been estimated for so many different genotypes, showing that significant and heritable variation exists. The predicted values were also used for Genome Wide Association studies to identify the genomic regions associated with canopy RUE and hence improved productivity. Sorghum being such a great genetic model, this may also help elucidate the genetic mechanisms underpinning photosynthetic efficiency and RUE in other cereals.

Sorghum is a drought-tolerant staple crop for half a billion people in Africa and Asia, an important source of animal feed throughout the world and a biofuel feedstock of growing importance. Cultivated sorghum and its inter-fertile wild relatives constitute the primary gene pool for sorghum. Understanding and characterizing the diversity within this valuable resource is fundamental for its effective utilization in crop improvement. Here, we report analysis of a sorghum pan-genome to explore genetic diversity within the sorghum primary gene pool. We assembled 13 genomes representing cultivated sorghum and its wild relatives, and integrated them with 3 other published genomes to generate a pan-genome of 44,079 gene families with 222.6 Mb of new sequence identified. The pan-genome displays substantial gene-content variation, with 64% of gene families showing presence/absence variation among genomes. Comparisons between core genes and dispensable genes suggest that dispensable genes are important for sorghum adaptation. Extensive genetic variation was uncovered within the pan-genome, and the distribution of these variations was influenced by variation of recombination rate and transposable element content across the genome. We identified presence/absence variants that were under selection during sorghum domestication and improvement, and demonstrated that such variation had important phenotypic outcomes that could contribute to crop improvement. The constructed sorghum pan-genome represents an important resource for sorghum improvement and gene discovery.

Variation in grain size, a major determinant of grain yield and quality in cereal crops, is determined by both the plant’s genetic potential and the available assimilate to fill the grain in the absence of stress. This study investigated grain size variation in response to variation in assimilate supply in sorghum using a diversity panel (n=837) and a BC-NAM population (n=1,421) across four experiments. To explore the effects of genetic potential and assimilate availability on grain size, the top half of selected panicles was removed at anthesis. Results showed substantial variation in five grain size parameters with high heritability. Artificial reduction in grain number resulted in a general increase in grain weight, with the extent of the increase varying across genotypes. Genome-wide association studies (GWAS) identified 44 grain size QTL that were likely to act on assimilate availability and 50 QTL that were likely to act on genetic potential. This finding was further supported by functional enrichment analysis and co-location analysis with known grain number QTL and candidate genes. RNA interference (RNAi) and overexpression experiments were conducted to validate the function of one of the identified gene, SbDEP1, showing that SbDEP1 positively regulates grain number and negatively regulates grain size by controlling primary branching in sorghum. Haplotype analysis of SbDEP1 suggested a possible role in racial differentiation. The enhanced understanding of grain size variation in relation to assimilate availability presented in this study will benefit sorghum improvement and have implications for other cereal crops.

Sorghum is primarily grown in hot and dry regions worldwide in large-scale commercial operations and in smallholder farming settings. In these regions, sorghum shows comparative advantages over other summer cereals, including its capacity to fill grain during end-of-season drought. It is also broadly adapted to temperate, subtropical and tropical drylands, and irrigated environments. Worldwide, farmers face the challenge of growing sorghum in highly variable environments. Matching hybrid, agronomy, and environment enables farmers to design more profitable and less risky sorghum production systems. At the crop level, the growth of major organs is predicted based on their potential size, and then the capacity of the crop to capture resources (radiation, water, and nitrogen) to meet the demand is assessed. The extent of resource capture and biomass accumulation and the efficiency with which carbon and nitrogen are partitioned into grain will be discussed, with a focus on productivity under water scarcity. One of the challenges for future sorghum crop improvement will be the capacity to connect across scales from molecular to farm, utilising molecular understanding to develop combinations of plant-level traits that increase productivity at the field level. This will require cross-disciplinary integration to harness ‘big’ data from genotypic and phenotypic studies. Future research in sorghum will need to focus on adaptation mechanisms that manipulate water supply and demand scenarios such as canopy size and root architecture, respectively, and heat adaptation mechanisms. Considerable biological integration will be required to scale-up from the causal polymorphisms at genome level to the phenotype of interest in the field. A new crop modelling frontier is unfolding in plant breeding with the potential to add significant value to the revolution in plant breeding associated with genomic technologies.

The efficient management and distribution of experimental data from pre-breeding projects is important to ensure uptake of valuable germplasm into breeding and research programmes. Being able to access and share this data in standard formats is essential in this process. The adoption of a common informatics platform for crops which may have limited resources brings economies of scale allowing common informatics components to be rolled out across multiple species. The close integration of such a platform with commonly used breeding software, visualization and analysis tools reduces the barrier for entry to researchers working on these data and provides a common framework to facilitate collaborations and data sharing. This work presents significant updates to the Germinate platform and highlights its value in distributing pre-breeding data for 14 crops as part of the project “Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives” (hereafter Crop Trust Crop Wild Relatives project) led by the Crop Trust (https://www.cwrdiversity.org). The addition of data on new crop species compliments data that are already publicly available on the platform. We present a suite of updated Germinate features using examples from these crop species and their wild relatives. The use of Germinate within the Crop Wild Relatives project demonstrates the usefulness of the system and the benefits that a shared informatics platform provides.These data resources provide a foundation on which breeding and research communities can develop additional online resources for their crops, harnessing new data as it becomes available, and benefiting collectively from future developments of the Germinate platform. Through this process Germinate will facilitate the utilization of plant genetic resources, including crop wild relatives. This article is protected by copyright. All rights reserved

The past decade has seen the increasing integration of magnetic resonance (MR) imaging into radiation therapy (RT). This growth can be contributed to multiple factors, including hardware and software advances that have allowed the acquisition of high-resolution volumetric data of RT patients in their treatment position (also known as MR simulation) and the development of methods to image and quantify tissue function and response to therapy. More recently, the advent of MR-guided radiation therapy (MRgRT) - achieved through the integration of MR imaging systems and linear accelerators - has further accelerated this trend. As MR imaging in RT techniques and technologies, such as MRgRT, gain regulatory approval worldwide, these systems will begin to propagate beyond tertiary care academic medical centers and into more community-based health systems and hospitals, creating new opportunities to provide advanced treatment options to a broader patient population. Accompanying these opportunities are unique challenges related to their adaptation, adoption, and use including modification of hardware and software to meet the unique and distinct demands of MR imaging in RT, the need for standardization of imaging techniques and protocols, education of the broader RT community (particularly in regards to MR safety) as well as the need to continue and support research, and development in this space. In response to this, an ad hoc committee of the American Association of Physicists in Medicine (AAPM) was formed to identify the unmet needs, roadblocks, and opportunities within this space. The purpose of this document is to report on the major findings and recommendations identified. Importantly, the provided recommendations represent the consensus opinions of the committee's membership, which were submitted in the committee's report to the AAPM Board of Directors. In addition, AAPM ad hoc committee reports differ from AAPM task group reports in that ad hoc committee reports are ne

In plant breeding, unmanned aerial vehicles (UAVs) carrying multispectral cameras have demonstrated increasing utility for high-throughput phenotyping (HTP) to aid the interpretation of genotype and environment effects on morphological, biochemical, and physiological traits. A key constraint remains the reduced resolution and quality extracted from “stitched” mosaics generated from UAV missions across large areas. This can be addressed by generating high-quality reflectance data from a single nadir image per plot. In this study, a pipeline was developed to derive reflectance data from raw multispectral UAV images that preserve the original high spatial and spectral resolutions and to use these for phenotyping applications. Sequential steps involved (i) imagery calibration, (ii) spectral band alignment, (iii) backward calculation, (iv) plot segmentation, and (v) application. Each step was designed and optimised to estimate the number of plants and count sorghum heads within each breeding plot. Using a derived nadir image of each plot, the coefficients of determination were 0.90 and 0.86 for estimates of the number of sorghum plants and heads, respectively. Furthermore, the reflectance information acquired from the different spectral bands showed appreciably high discriminative ability for sorghum head colours (i.e., red and white). Deployment of this pipeline allowed accurate segmentation of crop organs at the canopy level across many diverse field plots with minimal training needed from machine learning approaches.

Despite its importance for crop water use and productivity, especially in drought-affected environments, the underlying mechanisms of variation in intrinsic water-use efficiency (iWUE = net photosynthesis/stomatal conductance for water vapour, gsw) are not well understood, especially in C4 plants. Recently, we discovered that leaf width (LW) correlated negatively with iWUE and positively with gsw across several C4 grasses. Here, we confirmed these relationships within 48 field-grown genotypes differing in LW in Sorghum bicolor, a C4 crop adapted to dry and hot conditions. We measured leaf gas exchange and modelled leaf energy balance three times a day, alongside anatomical traits as potential predictors of iWUE. LW correlated negatively with iWUE and stomatal density, but positively with gsw, interveinal distance of longitudinal veins, and the percentage of stomatal aperture relative to maximum. Energy balance modelling showed that wider leaves needed to open their stomata more to generate a more negative leaf-to-air temperature difference, especially at midday when air temperatures exceeded 40°C. These results highlight the important role that LW plays in shaping iWUE through coordination of vein and stomatal traits and by affecting stomatal aperture. Therefore, LW could be used as a predictor of higher iWUE among sorghum genotypes.

One response to mitigate the impact of climate change on agricultural systems is to develop new varieties that are tolerant to the new range of biotic and abiotic challenges this change causes. This requires access to novel variants of genes for complex adaptive traits. Crop wild relatives are a potentially valuable source of these genes however these materials are often difficult to work with and identifying valuable alleles is difficult without substantial investment in pre-breeding. In this study we describe the development of a nested association mapping population for sorghum using two cultivated grain sorghum reference parents and 9 wild and exotic sorghum accessions as donors. The donor parents come from the verticilliflorum, drummondii and margaritiferum taxa and were sampled from a range of environments across Africa. In total the resource of consists of 13 populations and a total of 1,224 lines. The population has been genotyped with DArT markers which produced 42,372 unique SNP markers covering the genome. We determine the utility of the resource for high resolution mapping of complex traits by demonstrating that the exotics contain unique alleles for some example adaptive trait loci and by using the population for GWAS. The resource should provide useful material for plant breeders attempting to deal with the challenges generated by climate change. This article is protected by copyright. All rights reserved

Societal Impact Statement Sorghum is an important cereal crop that provides calories and nutrients for much of the world's population, and it is often grown with low fertiliser input. Optimising the yield, nutritive content and bioavailability of sorghum grain with minimal input is of importance for human nutrition, and arbuscular mycorrhizal (AM) fungi have previously shown potential to assist in this. Across sorghum genetic diversity, AM fungi improved the yield, nutrition and zinc and iron bioavailability of grain in a low phosphorus soil. Thus, food production systems that effectively manage AM fungi may improve consumer outcomes. Summary Sorghum is a C4 cereal crop that is an important source of calories and nutrition across the world, predominantly cultivated and consumed in low- and middle-income countries. Sorghum can be highly colonised by arbuscular mycorrhizal (AM) fungi, and the plant-fungal association can lead to improvements in biomass and nutrient uptake. High-throughput phenotyping allows us to non-destructively interrogate the ‘hidden’ effects of AM fungi on sorghum growth and phenology. Eight genetically diverse sorghum genotypes were grown in a soil amended with 2 or 20 mg P kg−1 and inoculated with an AM fungal culture of Rhizophagus irregularis. High-throughput phenotyping uncovered the ‘hidden’ effects of AM fungi on growth and phenology, while grain biomass, nutrition, Zn and Fe bioavailability and root AM colonisation was determined after destructive harvest. Sorghum plants colonised by AM fungi generally performed better than non-AM control plants, with greater yield, harvest indices, and grain P, Zn and Fe contents. During the early growth stages, AM colonisation led to temporary growth depressions. There were also AM fungal and P fertilisation effects on sorghum time-of-flowering. The sorghum genotype with the highest AM colonisation could barely produce grain when non-inoculated. The two genotypes that failed to mature had very low AM co

The pitching of a baseball is a strenuous action that applies exaggerated kinematic and kinetic influences at the elbow of the athlete. The repeated application of these influences can gradually degrade the mechanical integrity of the native biological support structures over time and eventually lead to failure by fatigue. One such structure is the anterior bundle of the ulnar collateral ligament (AMCL). The fatigue properties of a material are often characterized by its respective fatigue life, where the amount of repetitive loading possible for a given load state before failure is defined. It is also important to predict how the damage is progressing throughout the material for cycles which are less than the predicted failure life. This study seeks to determine these properties of fatigue for the elbow AMCL and implement them into the execution of a Finite Element (FE) simulation for the purpose of predicting the magnitude and location of damage to the AMCL, per magnitude of pitching action performed. For applicability to the general pitching athlete, these results will be formulated using a non-dimensional material model. Twenty-two cadaveric elbow specimens were used for this study. Eleven were tested in vertical elongation to make measurement of the AMCL elastic mechanical properties and subsequently tested to failure. Eleven contralateral specimens were tested in valgus fatigue to make measurement of the AMCL fatigue properties. These results were incorporated into a transversely isotropic hyperelastic constitutive equation and used to define the material properties of a 3D elbow model within a FE environment. Simulated displacements mimicking pitching-induced joint opening were applied and both the stress and strain outputs were analyzed. The average tensile failure load was 595.25 N ± 201.93 N. For specimens tested at 90% and 80% of their estimated one-cycle failure moment, the average cycles to failure were 3211 ± 4721.33 and 25063 ± 30487.58, respectively.

Main conclusion: Plant height was positively correlated with grain yield across a large set of 3-dwarf sorghum hybrids and production environments in north-eastern Australia. In industrialised countries, plant breeders tend to select for short plant stature in cereals like wheat, barley and rice, but also grain sorghum. This is mainly to prevent stalk lodging and to allow for machine harvesting. However, this counteracts an intrinsic positive relationship between plant height and yield potential often observed in cereals. We used data from multi-environment breeding trials comprising large sets of female sorghum lines from a range of pedigrees in hybrid combination with five different male testers. The hybrids were grown in 22 different rainfed environments in north-eastern Australia, which allowed us to thoroughly examine the relationship between plant height and yield across a range of productivity levels. Covariate analysis showed that in 38 out of the 90 tested relationships, grain yield was significantly (p < 0.05) positively and in only one case significantly negatively associated with plant height. This strong positive association between the traits was supported by the observation that 87% of the effects were either positive or zero. The effects of height on yield ranged from a decrease of 0.015 t ha−1 to an increase of 0.057 t ha−1 cm−1. The majority of the negative effects were observed in low-yielding trials and the positive effect of height tended to increase with increasing mean trial yield. Opportunities to increase yield potential by selecting for slightly taller sorghum hybrids therefore need to be explored in context with the target environments and in combination with other means to control the risks of lodging.

Despite its importance for crop water use and productivity, especially in drought-affected environments, the underlying mechanisms of variation in intrinsic water-use efficiency (iWUE = net photosynthesis/stomatal conductance for water vapour, gsw ) are not well understood, especially in C4 plants. Recently, we discovered that leaf width (LW) correlated negatively with iWUE and positively with gsw across several C4 grasses. Here, we confirmed these relationships within 48 field-grown genotypes differing in LW in Sorghum bicolor, a C4 crop adapted to dry and hot conditions. We measured leaf gas exchange and modelled leaf energy balance three times a day, alongside anatomical traits as potential predictors of iWUE. LW correlated negatively with iWUE and stomatal density, but positively with gsw , interveinal distance of longitudinal veins, and the percentage of stomatal aperture relative to maximum. Energy balance modelling showed that wider leaves needed to open their stomata more to generate a more negative leaf-to-air temperature difference, especially at midday when air temperatures exceeded 40°C. These results highlight the important role that LW plays in shaping iWUE through coordination of vein and stomatal traits and by affecting stomatal aperture. Therefore, LW could be used as a predictor of higher iWUE among sorghum genotypes.

The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.

This is a chapter of the 2021 Field Crops PMG. The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products that also may be suitable.

This publication included a guide for peanut growers including agronomic, insect, disease management along with weed control, and irrigation and safety information. Archived Peanut Production Guides can be accessed from: http://www.sites.ext.vt.edu/newsletter-archive/peanut-production/index.html

We give a new, algebraically computable formula for skein modules of closed 3-manifolds via Heegaard splittings. As an application, we prove that skein modules of closed 3-manifolds are finite-dimensional, resolving in the affirmative a conjecture of Witten.

From plowing state highways on snowy days to keeping the state's economic engine humming to supporting Utah's most vulnerable, state government employees work diligently to serve the citizens of Utah. We know they are dedicated and committed to public service. Still, everyone can improve. That's why Governor-elect Cox and Lt. Governor-elect Henderson asked dozens of volunteers to look under the hood of state government departments. Most of these volunteers didn't have expertise in their assigned subject areas because the incoming administration wanted a fresh look at how departments were serving you, the state's customers. The teams who examined the state's 25 departments provided great insights, praised performance and, in some cases, offered ways to make state government even better over the next four years.

Key message: Multi-environment models using marker-based kinship information for both additive and dominance effects can accurately predict hybrid performance in different environments. Abstract: Sorghum is an important hybrid crop that is grown extensively in many subtropical and tropical regions including Northern NSW and Queensland in Australia. The highly varying weather patterns in the Australian summer months mean that sorghum hybrids exhibit a great deal of variation in yield between locations. To ultimately enable prediction of the outcome of crossing parental lines, both additive effects on yield performance and dominance interaction effects need to be characterised. This paper demonstrates that fitting a linear mixed model that includes both types of effects calculated using genetic markers in relationship matrices improves predictions. Genotype by environment interactions was investigated by comparing FA1 (single-factor analytic) and FA2 (two-factor analytic) structures. The G×E causes a change in hybrid rankings between trials with a difference of up to 25% of the hybrids in the top 10% of each trial. The prediction accuracies increased with the addition of the dominance term (over and above that achieved with an additive effect alone) by an average of 15% and a maximum of 60%. The percentage of dominance of the total genetic variance varied between trials with the trials with higher broad-sense heritability having the greater percentage of dominance. The inclusion of dominance in the factor analytic models improves the accuracy of the additive effects.Breeders selecting high yielding parents for crossing need to be aware of effects due to environment and dominance.

Rationale and Objectives: Iodine quantification (IQ) and virtual noncontrast (VNC) images produced by dual-energy CT (DECT) can be used for various clinical applications. We investigate the performance of dual-layer DECT (DLDECT) in different phantom sizes and varying radiation doses and tube voltages, including a low-dose pediatric setting. Materials and Methods: Three phantom sizes (simulating a 10-year-old child, an average, and a large-sized adult) were scanned with iodine solution inserts with concentrations ranging 0-32 mg/ml, using the DLDECT. Each phantom size was scanned with CTDIvol 2-15 mGy at 120 and 140 kVp. The smallest phantom underwent additional scans with CTDIvol 0.9-1.8 mGy. All scans were repeated 3 times. Each iodine insert was analyzed using VNC and IQ images for accuracy and precision, by comparison to known values. Results: For scans from 2 to 15 mGy mean VNC attenuation and IQ error in the iodine inserts in the small, medium, and large phantoms was 1.2 HU +/- 3.2, -1.2 HU +/- 14.9, 2.6 HU +/- 23.6; and +0.1 mg/cc +/- 0.4, -0.9 mg/cc +/- 0.9, and -1.8 mg/cc +/- 1.8, respectively. In this dose range, there were no significant differences (p >= 0.05) in mean VNC attenuation or IQ accuracy in each phantom size, while IQ was significantly less precise in the small phantom at 2 mGy and 10 mGy (p < 0.05). Scans with CTDIvol 0.9-1.8 mGy in the small phantom showed a limited, but statistically significantly lower VNC attenuation precision and IQ accuracy (-0.5 HU +/- 5.3 and -0.3 mg/cc +/- 0.5, respectively) compared to higher dose scans in the same phantom size. Conclusion: Performance of iodine quantification and subtraction by VNC images in DLDECT is largely dose independent, with the primary factor being patient size. Low-dose pediatric scan protocols have a significant, but limited impact on IQ and VNC attenuation values.

This paper reports a first study exploring genomic prediction for adaptation of sorghum [Sorghum bicolor (L.) Moench] to drought-stress (D-ET) and non-stress (W-ET) environment types. The objective was to evaluate the impact of both modeling genotype-by-environment interaction (G × E) and accounting for heterogeneous variances of marker effects on genomic prediction of parental breeding values for grain yield within and across environment types (ET). For this aim, different genetic covariance structures and different weights for individual markers were investigated in BLUP-based prediction models. The BLUP models used a kinship matrix combining pedigree and genomic information, termed K-BLUP. The dataset comprised testcross yield performances under D-ET and W-ET as well as pedigree and genomic data. In general, modeling G × E increased predictive ability and reduced empirical bias of genomic predictions for broad adaptation across both ETs compared to models that ignored G × E by fitting a main genetic effect only. Genomic predictions for specific adaptation to D-ET or to W-ET were also improved by K-BLUP models that explicitly accommodated G × E and used data from both ETs, relative to prediction models that used data from the targeted ET exclusively or models that used all the data but assumed no G × E. Allowing for heterogeneous marker variances through weighted K-BLUP produced clear increments (between 43% and 72%) in predictive ability of genomic prediction for grain yield in all adaptation scenarios. We conclude that G × E as well as locus-specific genetic variances should be accommodated in genomic prediction models to improve adaptability of sorghum to variable environmental conditions. This article is protected by copyright. All rights reserved

Key message : We detected 213 lodging QTLs and demonstrated that drought-induced stem lodging in grain sorghum is substantially associated with stay-green and plant height suggesting a critical role of carbon remobilisation. Abstract :Sorghum is generally grown in water limited conditions and often lodges under post-anthesis drought, which reduces yield and quality. Due to its complexity, our understanding on the genetic control of lodging is very limited. We dissected the genetic architecture of lodging in grain sorghum through genome-wide association study (GWAS) on 2308 unique hybrids grown in 17 Australian sorghum trials over 3 years. The GWAS detected 213 QTLs, the majority of which showed a significant association with leaf senescence and plant height (72% and 71%, respectively). Only 16 lodging QTLs were not associated with either leaf senescence or plant height. The high incidence of multi-trait association for the lodging QTLs indicates that lodging in grain sorghum is mainly associated with plant height and traits linked to carbohydrate remobilisation. This result supported the selection for stay-green (delayed leaf senescence) to reduce lodging susceptibility, rather than selection for short stature and lodging resistance per se, which likely reduces yield. Additionally, our data suggested a protective effect of stay-green on weakening the association between lodging susceptibility and plant height. Our study also showed that lodging resistance might be improved by selection for stem composition but was unlikely to be improved by selection for classical resistance to stalk rots.

Background and Objectives Injera (a fermented pancake-like product) is a traditional food in Ethiopia but is traditionally made from tef (Eragrostis tef). But sorghum also a traditional Ethiopian crop can be used although considered having a lower quality. A 139 sorghum (Sorghum bicolor) cultivars and their corresponding injera were tested for a range of chemical tests, namely total starch, amylose, and tannin contents, plus a newly developed image analysis program to provide objective measures of the injera. Findings The results showed several sorghums were superior to tef in making injera, based on the chemical, image, and/or sensory analysis. Tannin content was highly positively correlated with color and negatively with taste, while high starch content was more related to softness and rollability. The imaging analysis also provided a rapid and more objective assessment of injera. Two sensory traits, color and eye evenness, were strongly positively correlated to the image data, through L*, a* and b*, and average pixel count per “eye,” respectively. Conclusions Quality testing involving human sensory panels within a breeding program is time consuming, costly and can be impractical for the selection of superior lines from large numbers of selection candidates to the next stage. Objective tests such as imaging analysis can be used at earlier stages in the breeding program which would allow breeding lines with suitable injera quality to be progressed. This would result in new sorghum varieties with fresh injera quality similar too or better than tef. Significance and novelty A new image analysis program compliments chemical analysis for early screening of sorghums for injera, saving time and costs.

Sorghum in Australia is grown in water-limited environments of varying extent, generating substantial genotype × environment interactions (GEIs) for grain yield. Much of the yield variation and GEI results from variations in flowering time and tillering through their effects on canopy development. The confounding effects of flowering and tillering complicate the interpretation of breeding trials. In this study, we evaluated the impacts of both flowering time (DTF) and tillering capacity (FTN) on the yield of 1741 unique test hybrids derived from three common female testers in 21 yield testing trials (48 tester/trial combinations) across the major sorghum production regions in Australia in three seasons. Contributions of DTF and FTN to genetic variation in grain yield were significant in 14 and 12 tester/trial combinations, respectively. The proportion of genetic variance in grain yield explained by DTF and FTN ranged from 0.2% to 61.0% and from 1.4% to 56.9%, respectively, depending on trials and genetic background of female testers. The relationship of DTF or FTN with grain yield of hybrids was frequently positive but varied across the genetic background of testers. Accounting for the effects of DTF and FTN using linear models did not substantially increase the between-trial genetic correlations for grain yield. The results suggested that other factors affecting canopy development dynamics and grain yield might contribute GEI and/or the linear approach to account for DTF and FTN on grain yield did not capture the complex non-linear interactions.

Sorghum [Sorghum bicolor (L.) Moench] is an important dryland crop in the semiarid tropics, and temperature and photoperiod are the main environmental factors affecting its phenology and thus adaptation. The objectives of this study were to quantify the response of development rate to temperature and photoperiod for 19 diverse Ethiopian sorghum genotypes, and to determine if differences in these responses could be linked to racial grouping or agroecological adaptation. The genotypes, representing four major sorghum races and adaptation to four agroecological zones, were sown on 12 dates at two locations in Ethiopia with contrasting altitude. This created a range in photoperiod and temperatures relevant to Ethiopian conditions. Days from emergence to flag leaf appearance, anthesis, and maturity were recorded. A predictive phenology modeling framework was used to fit the effects of photoperiod and temperature on the rate of development for both the pre- and post-anthesis periods. Results indicated that the pre-anthesis development rate was independent of photoperiod for the range tested. This result differed from West African germplasm and likely reflects differences in agroecological adaptation and racial background. Significant genotypic differences were observed for the base temperature (0–9.8 °C) and for the optimum rate of development (0.011–0.022 d–1, with low value indicating late anthesis), with differences related to agroecology and racial type. Post-anthesis differences in the temperature response were minor. The observed differences in pre-anthesis base temperature can positively affect sorghum breeding programs globally, especially in temperate regions where suitability for early spring plantings is often restricted by low temperatures.

Grown in water-limited environments, sorghum (Sorghum bicolor (L.) Moench) is often exposed to water deficits of varying extent and timing. One of the impacts of water stress on sorghum production is lodging; however, there has been no published study quantifying the temporal and spatial frequency and severity of lodging in grain sorghum in Australia. In this study, we investigated the frequency and severity of lodging, using a dataset of 83 advanced yield-testing trials of the sorghum pre-breeding program grown in the seven major sorghum-production environments in Australia over 14 summer growing seasons. Lodging occurred in most production regions but with varying frequency and severity. Lodging was significantly greater in regions that were more prone to water stress (e.g. Central Highlands in Queensland) and significantly lower in regions that were less likely to suffer from water stress (e.g. Liverpool Plains in northern New South Wale) compared with the overall average across regions. The severity of lodging also varied across regions, with the most severe lodging (>20%) occurring in Central Highlands and Western Downs in Queensland. In addition, seasonal patterns of lodging frequency and severity were also observed. Over the 14 growing seasons, the frequency of lodging varied from 0% to 100%, with the most severe lodging (>20%) observed in 2005, 2016 and 2017. The Southern Oscillation Index explained 29% of the seasonal variation in lodging frequency. The findings of this study clearly support a link between lodging incidence and water stress across regions and seasons. Our data also showed that although there was a substantial turnover of commercial hybrids during the period of this study, the level of resistance to lodging appeared not to have improved. It is possible that this is due to plant breeders trading off improvements in lodging resistance to increase grain yield.

Drought is a recurring phenomenon that puts crop yields at risk and threatens the livelihoods of many people around the globe. Stay-green is a drought adaption phenotype found in sorghum and other cereals. Plants expressing this phenotype show less drought-induced senescence and maintain functional green leaves for longer when water limitation occurs during grain fill, conferring benefits in both yield per se and harvestability. The physiological causes of the phenotype are postulated to be water saving through mechanisms such as reduced canopy size or access to extra water through mechanisms such as deeper roots. In sorghum breeding programs, stay-green has traditionally been assessed by comparing visual scores of leaf senescence either by identifying final leaf senescence or by estimating rate of leaf senescence. In this study, we compared measurements of canopy dynamics obtained from remote sensing on two sorghum breeding trials to stay-green values (breeding values) obtained from visual leaf senescence ratings in multienvironment breeding trials to determine which components of canopy development were most closely linked to the stay-green phenotype. Surprisingly, canopy size as estimated using preflowering canopy parameters was weakly correlated with stay-green values for leaf senescence while postflowering canopy parameters showed a much stronger association with leaf senescence. Our study suggests that factors other than canopy size have an important role in the expression of a stay-green phenotype in grain sorghum and further that the use of UAVs with multispectral sensors provides an excellent way of measuring canopy traits of hundreds of plots grown in large field trials.

Grain size is a key yield component of cereal crops and a major quality attribute. It is determined by a genotype’s genetic potential and its capacity to fill the grains. This study aims to dissect the genetic architecture of grain size in sorghum. An integrated genome-wide association study (GWAS) was conducted using a diversity panel (n = 837) and a BC-NAM population (n = 1421). To isolate genetic effects associated with genetic potential of grain size, rather than the genotype’s capacity to fill the grains, a treatment of removing half of the panicle was imposed during flowering. Extensive and highly heritable variation in grain size was observed in both populations in 5 field trials, and 81 grain size QTL were identified in subsequent GWAS. These QTL were enriched for orthologues of known grain size genes in rice and maize, and had significant overlap with SNPs associated with grain size in rice and maize, supporting common genetic control of this trait among cereals. Grain size genes with opposite effect on grain number were less likely to overlap with the grain size QTL from this study, indicating the treatment facilitated identification of genetic regions related to the genetic potential of grain size. These results enhance understanding of the genetic architecture of grain size in cereal, and pave the way for exploration of underlying molecular mechanisms and manipulation of this trait in breeding practices.