22 research outputs found

    Genotype × Environment Interaction: A Prerequisite for Tomato Variety Development

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    Tomato (Solanum lycopersicum L.) is the second most important vegetable crop in the world due to its high level of nutrition particularly in vitamins and antioxidants. It is grown in several ecologies of the world due to its adaptability and ease of cultivation. Besides field conditions, tomatoes are grown in controlled environments which range from hydroponics and simple high tunnel structures to highly automated screen houses in advanced countries. However, the yield and quality of the fruits are highly influenced by the environment. This results in unpredictable performances in different growing environments in terms of quality, a phenomenon known as genotype by environment (G × E) interaction which confounds selection efficiency. Various approaches are employed by plant breeders to evaluate and address the challenges posed by genotype by environment interaction. This chapter discusses various field and controlled environments for growing tomatoes and the effect of these environments on the performance of the crop. The various types of genotype × environment interactions and their effect of the tomato plant are discussed. Finally, efforts are made to suggest ways and methods of mitigating the confounding effects of genotype × environment interaction including statistical approaches

    Perspective Chapter: Accelerating Demand-Led Tomato Breeding for Emerging Markets in Africa

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    Tomato production in Africa has increased due to increased population, rising consumer demands for nutritious and healthy food and potential use of improved technologies. Demand-led’ plant breeding puts producers and consumers at the heart of research and development involving stakeholders even before the research starts. These ‘stakeholders’ are not only farmers but key actors along the tomato value chain. They influence how the tomato is traded as: fresh food and processing product. This chapter focuses on different approaches to fast-track tomato breeding so as to contribute to the transformation of African agriculture by enabling small scale farmers to compete in local and regional markets, by increasing the availability and adoption of high performing tomato varieties that meet market demands. It further outlines development of varieties that meet farmer needs, consumer preferences, and market demand in Africa. These new varieties are designed to meet client needs by connecting plant breeders with crop value chains, seed distribution organizations, and encouraging enterprise and entrepreneurship in transforming agriculture in Africa. Lastly, it outlines the prospects and challenges associated with demand-led breeding of tomato and offers suggestions to increase food security in Africa

    A Meta-Analysis of Modifications of Root System Traits of Crop Plants to Potassium (K) Deprivation

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    Unlike nitrogen (N) and phosphorus (P), morphological responses of root systems of crop plants to potassium (K) dynamics in soils or growth media are only gaining currency. This is due to the realization of the instrumental role of K in several cellular and tissue level processes crucial for the growth, stress tolerance, metabolic functions, and yield of crop plants, and ultimately, food security and sustainable agriculture. This chapter used meta-analysis to synthesize the pooled evidence for modifications in several root system traits of different crop plants under conditions of K starvation in different growth media. In all, 37 studies that passed inclusion/exclusion criteria, from 1969 to 2019, were analyzed in aggregate and then disaggregated for root biomass, root length, and the number of roots. Three moderators were analyzed: type of soil or growth medium, crop, and K fertilizer applied in the included studies. The aggregated results show that the cumulative effect of K deprivation was a significant and large reduction (about 25.5 ± 15.0%) in the bulk of root system traits considered, which was slightly lower than the reduction in shoot- or yield-related traits. Reductions of approximately 38 ± 38.0% in root biomass and 23.2 ± 18.6% in root length were observed, and the magnitudes of reduction were comparable to those observed from the disaggregated data. Though reductions in root system traits due to K starvation occurred under both greenhouse/lab and field conditions, the cumulative reduction in the former was significantly larger than that of the latter. Among the moderators, the effect of type of soil (or growth media) and crop on the scale of modification of root system traits to K deprivation are stronger compared to the effect of type of K fertilizer applied. It is concluded that, overall, K deprivation leads to significant reductions in root system traits, especially root biomass and length in soils and perlite regardless of the type of K fertilizer applied. Attention should be given to K management in cropping systems to avoid K starvation, especially at the early and vegetative stages, and to improve K reserves in soils. Further attention should be given to the responses of root system traits to K supply when matching crops to soils

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

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    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Assessing Flood Tolerance Potential of Papaya Germplasm at the Juvenile Stage

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    Aims:&nbsp;To assess flood tolerance potential of papaya germplasm and determine physiological basis of observed tolerance. Study Design:&nbsp;Both Experiment 1 and 2 were in RCBD with 2 and 3 treatments respectively. Place and Duration of Study:&nbsp;Experiments were conducted in a screen-house at the Kwadaso Station of Crops Research Institute, Ghana between February and September 2014. Methodology:&nbsp;Six weeks old seedlings of 30 papaya accessions were subjected to 90% partial flooding (F90) by standing planting bags with seedlings in 15 L bucket filled with water up to 90% of height of soil level in bags. Control (non-stressed: NS) plants were watered regularly for 1 week. Post flooding recovery of seedlings was monitored for 1 week. In Experiment 2, seedlings of 6 papaya accessions were subjected to 100% flooding (F100) or 50% partial flooding (F50) for 5 weeks, and a post flood recovery period of 6 weeks. Plant height, girth and biomass were measured together with leaf SPAD chlorophyll content, chlorophyll fluorescence, RWC and senescence. Results:&nbsp;None of the 30 papaya accessions had high flood tolerance potential, with 60% of accessions studied having low flood tolerance. F90 plants had reduced height and girth relative to control (p&lt;.001). Leaf senescence was high in F90 plants (p&lt;.001). All six accessions used in Experiment 2 could not withstand 100% flooding longer than 3 days. F50 treatment increased lateral root biomass (p&lt;.001), although controls had higher tap root (p&lt;.001), total root (p=.02) and total plant biomass (p=.002) than F50 plants. Leaf RWC (p=.89), SPAD chlorophyll content (p=.05) and chlorophyll fluorescence (p=.24) were not negatively affected by F50 treatment. Conclusion:&nbsp;None of the papaya accessions studied was able to withstand complete flooding. However, most could tolerate partial flooding of roots for 5 weeks and resume normal growth after release from flood stress

    Agronomic biofortification of selected underutilised solanaceae vegetables for improved dietary intake of potassium (K) in Ghana

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    Agronomic biofortification is the deliberate use of mineral fertilizers to increase the concentration of a target mineral in edible portions of crops to increase dietary intake of the target mineral. Globally, increased dietary intake of potassium (K) is becoming a part of the strategy to address hidden hunger and related non-communicable diseases such as hypertension and cardiac disorders. This study aimed at demonstrating the efficacy of increasing the concentration of K in the edible portions of three commonly consumed but underutilized solanacea vegetables (Solanum aethiopicum, S. macrocarpon and S. torvum) in Ghana. The effects of different types and rates of K fertilizer application on the leaf- and fruit-K contents of the vegetables, as well as the K loss between the raw and cooked fruits were investigated. Five levels of each of three types of K fertilizer (liquid drench of potassium chloride, granular Muriate of potash and Sulphate of potash) were applied to each of the three field-grown vegetables. Yield data were collected and the fruits and leaves were analysed for the content of K, N, P, Ca, Fe, Zn and Cu. The results showed the rate of fertilizer application had significant effect on the yields of S. aethiopicum and macrocarpon but the yield of S. torvum was significantly affected by type, rate and interactive effect of type and rate of fertilizer application. Fruit K concentrations were greatest for S. aethiopicum (2130 mg K kg−1 DW) and S. torvum (1883 mg K kg−1 DW) with liquid KCl but with Sulphate of Potash for S. macrocarpon (1801 mg K kg−1 DW). There were higher K concentrations in leaves than in fruits of all the vegetables. Household cooking of the fruits resulted in the retention of over 70% of the K content in the raw fruits. Potassium fertilization increased the Ca, Fe, and Zn contents of S. aethiopicum and S. torvum. It is concluded that agronomic biofortification may be a useful strategy to increase K intakes and other important elements (e.g. Fe and Zn) in the vegetables studied
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