Assessment of Genotype by Environment interactions and Grain Yield Performance of Extra-Early Maize (Zea Mays L.) Hybrids

Maize (Zea mays L.) is one of the most important cereal crops of Ghana in terms of production and consumption. Currently, it is produced in all the agro-ecological zones of the country. In Ghana, Genotype by Environment interactions (GxE) effects on maize grain yield is usually significant due to the diverse environmental conditions at growing sites. A proper understanding of the effects of GxE on variety evaluation and cultivar recommendations is vital. The study was conducted in 2011 at three locations in Ghana to (i) determine the presence of GxE of 100 extra-early maize genotypes and (ii) To use the GGE biplot methodology to determine grain yield performance and stability of the genotypes evaluated across three environments. The effects of genotype and environment were significant (P < 0.01) for grain yield. However, GxE was not significant for the same trait. TZEEI 8 x TZEEI 51, TZEEI 5 x TZEEI 53, TZEEI 21 x TZEEI 39, TZEEI 27 x TZEEI 36 and TZEEI 4 x TZEEI 6 were identified as high yielding and most stable hybrids. Therefore, these hybrids have the potential for production across the test locations as well as others within the same agro-ecological zones. On the contrary, DODZI, TZEEI 23 x TZEEI 6, TZEEI 19 x TZEEI 24, TZEEI 11 x TZEEI 24 and TZEEI 20 x TZEEI 39 were not only low yielding but also among the least stable genotypes. Keywords: Zea mays, single-cross, stability, multiple environments, Gx

Onfarm evaluation of maize varieties in the transitional and savannah zones of Ghana: determinants of farmer preferences

Maize is one of the most important food crops in Ghana even though its production has not reached self sufficiency levels. Drought and striga infestation are among the most important production constraints of maize in Ghana. Promising high yielding, drought and striga tolerant maize varieties are being evaluated by CSIR and IITA in participatory on-farm trials and demonstrations. These varieties however need to meet farmers’ varietal preferences in order for them to adopt. This study therefore sought to assess farmers’ preference for the different drought tolerant maize varieties, and determine factors that influence their choices. Kendall’s coefficient of concordance was used to test the level of agreement between farmers on their preferences. The ordered logistic regression was used to estimate the determinants of farmer’s preference using cross-sectional observations from 120 maize farmers in the Transitional and Savannah zones of Ghana. Results indicate that maize varieties that are early maturing (2.38) and drought tolerant (2.45) were most preferred by farmers. Area under maize cultivation, fertilizer usage and family size are the factors that were found to influence farmers’ preference for improved maize varieties. These factors should therefore be considered in varietal promotion

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Breeding strategies to improve maize for adaptation to low soil nitrogen in West and Central Africa

The moist savannas of West and Central Africa have great potential for maize grain production due to high levels of radiation and reduced incidence of pests and diseases. However, soils in this zone are generally low in organic matter and cation exchange capacity in addition to land use intensification. Improving productivity of maize in the savannas will therefore rely on improving soil fertility, ensuring efficient use of inputs and low-N tolerant maize varieties. Breeding maize for adaptation to low soil nitrogen will enhance the capacity of cultivars to use limited nitrogen more efficiently for grain production. Attempts at developing N-efficient maize genotypes for this region resulted in the identification of hybrids as having better N-use efficiency than open pollinated cultivars, identification of inbreds with high N-use efficiency and the development of prolific and low-N tolerant populations. Recurrent selection schemes whereby desirable progenies for recombination were selected based on an index that combine agronomic performance under low-N with yield under high-N to maximize gains under both environments, have been used to improve the developed populations. Evaluation of different cycles of selection showed that a minimum yield gain of 100 kg ha-1 cycle-1 under low-N is feasible. This yield gain is associated with desirable changes in other agronomic traits. Determination of relationships between vertical root pulling strength and nitrogen uptake and use efficiency and testing of maize genotypes developed for drought under low-N are other strategies that can aid breeding for tolerance to low-soil nitrogen

Participatory variety selection of okra (Abelmoschus esculentus L.) genotyes for adaptation to the semi-arid agro-ecology of northern Ghana

In a two-year study, participatory variety selection (PVS) was employed to evaluate the performance of 19 okra (Abelmoschus esculentus L.) c. v. Moench genotypes in a semi-arid agro-ecology in northern Ghana. The PVS sessions were organized at 65, 80 and 95 days after planting for 272 farmers to select the most preferred genotypes base on plant growth, maturity period and yield components. Results of this study indicate high significant differences among the genotypes (P< 0.0001) for most essential agronomic yield traits evaluated. Five most recurring preference traits were high fruit yield, early maturing, multiple harvest frequency, drying quality and long tender-life. Glabrous leaf, stem and fruit were important to farmers because most of the production operations are still being manually done. Genotypes with high potential included: NOKH 1004 (9.55 ton\ha), FV-Unn-manna (5.85 ton\ha), NOHK 1003 (5.17 ton\ha), NOKH 1002 (2.83 ton\ha), FV-Kpazeya (2.83 ton\ha), TZ-SMN-86 (2.30 ton\ha), AAK (2.11 ton\ha), NB-55-Srivan (1.98 ton\ha), Sasilon (1.70 ton\ha), FV-Unn (2.20 ton\ha) and Ex-Makutopora (1.27 ton\ha). Genotypes Sasilon, NOKH-1004, NB-55-Srivan and NOKH-1003 recorded the highest ranking among farmers during the PVS. High yielding and early maturing genotypes which are amendable to drying may show wide adoption rate due to the premium on dehydrated okra. These genotypes can be suggested as candidates for inspection by the National Variety Release and Technical Committee for release to farmers to increase access to improved okra varieties

Trait association for improved grain yield of extra-early maturing maize hybrids evaluated in the forest and transitional zones of Ghana

Abstract The present study used sequential path analysis and factor analysis to determine the interrelationship between grain yield and other agronomic traits of 100 extra-early maturing maize genotypes. The objective was to identify traits with the greatest influence on grain yield for use as selection criteria in future breeding programmes. The coefficient of correlations revealed that grain yield correlated positively with ear aspect, days to anthesis, days to silking, plant height, and number of ears harvested per plot and plant stand. Grain yield was however, negatively correlated to husk cover and ear number per plant. Path analysis identified plant height and number of ears harvested per plot to have a positive direct effect on grain yield while ear number per plant had a negative direct effect on grain yield. Also, plant stand, number of ears harvested per plot and ear aspect were identified to have the greatest influence on yield by factor analysis

Performance of extraearly maize cultivars based on GGE biplot and AMMI analysis

Published online: 05 October 2011Multi-environment trials (METs) in West Africa have demonstrated the existence of genotype×environment interactions (G×E), which complicate the selection of superior cultivars and the best testing sites for identifying superior and stable genotypes. Two powerful statistical tools available for MET analysis are the additive main effects and multiplicative interaction (AMMI) and the genotype main effect+G×E (known as GGE) biplot. The objective of the present study was to compare their effectiveness in identifying maize mega-environments and stable and superior maize cultivars with good adaptation to West Africa. Twelve extra-early maturing maize cultivars were evaluated at 17 locations in four countries in West Africa from 2006 to 2009. The effects of genotype (G), environments (E) and G×E were significant (P<0 01) for grain yield. Differences between E accounted for 0 75 of the total variation in the sum of squares for grain yield, whereas the G effects accounted for 0 03 and G×E for 0 22. The GGE biplot explained 0 74 of total variations in the sum of squares for grain yield and revealed three mega-environments and seven cultivar groups. The AMMI graph explained 0 13 and revealed four groups each of environments and cultivars. The two procedures provided similar results in terms of stability and performance of the cultivars. Both methods identified the cultivars 2004 TZEE-W Pop STR C4 and TZEE-W Pop STR C4 as superior across environments. Cultivar 2004 TZEE-W Pop STR C4 was the most stable. The GGE biplot was more versatile and flexible, and provided a better understanding of G×E than the AMMI graph. It identified Zaria, Ilorin, Ikenne, Ejura, Kita, Babile, Ina and Angaredebou as the core testing sites of the three mega-environments for testing the Regional Uniform Variety Trials-extra-early

Performance of maize populations under different nitrogen rates in northern Ghana

This study evaluated grain yield performance, stability and agronomic nitrogen-use efficiency (AE) of twelve maize populations under three nitrogen (N) rates at two locations in the Guinea and Sudan savannah zones of Ghana in 2014 and 2015. The N rates used were 0, 30, and 90 kg N ha−1. Computations were made for grain yield and AE. Populations × nitrogen interactions were significant for grain yield and AE at the three N rates. The mean yield of the populations under 0, 30, and 90 kg N ha−1 were 1.42, 4.12, and 6.80 t ha−1, respectively. Mean AE of the populations under low-N and high-N was 90.34 and 59.73 kg kg−1, respectively. Populations LNP-Syn-W, TZPB-LN-Syn and IWD-C2-Syn-F2 were efficient under both low-N and high-N inputs and produced 229.17 kg ha−1 and 572.5 kg ha−1 more grains than the average yield of all the populations under low-N and high-N, respectively. The results of this study indicated that the highest response to selection of N-efficient maize populations is achieved under low-N when the grain yield reduction at low-N is 39% of those of high-N environments. Keywords: Grain yield stability, Low soil nitrogen, Nitrogen use efficiency, Genotype × nitrogen interactio

IL-33 expression is lower in current smokers at both transcriptomic and protein level

INTRODUCTION: IL-33 is a pro-inflammatory cytokine thought to play a role in the pathogenesis of asthma and COPD. A recent clinical trial using the anti-IL33 antibody showed a reduction in exacerbation and improved lung function in ex-smokers but not current smokers with COPD. In this study, we aimed to understand the effects of smoking status on IL-33. METHODS: We investigated the association of smoking status with the level of gene expression of IL33 in the airways in eight independent transcriptomic studies of lung airways. Additionally, we performed western blot and immunohistochemistry for IL-33 in lung tissue to assess protein levels. RESULTS: Across the bulk RNA-sequencing datasets, IL-33 gene expression and its signaling pathway were significantly lower in current- compared to ex- or never-smokers and increased upon smoking cessation (p<0.05). Single-cell sequencing showed that IL-33 is predominantly expressed in resting basal epithelial cells and decreases during the differentiation process triggered by smoke exposure. We also found a higher transitioning of this cellular sub-population into a more differentiated cell type during chronic smoking, potentially driving the reduction of IL-33. Protein analysis demonstrated lower IL-33 levels in lung tissue from COPD current- compared to ex-smokers and a lower proportion of IL-33 positive basal cells in current versus ex-smoking controls. CONCLUSION: We provide strong evidence that cigarette smoke leads to an overall reduction in IL33 expression in both transcriptomic and protein level and this may be due to the decrease in resting basal cells. Together, these findings may explain the clinical observation that a recent antibody-based anti-IL-33 treatment is more effective in ex- than current smokers with COPD

Spatiotemporal differences and uncertainties in projections of precipitation and temperature in South Korea from CMIP6 and CMIP5 general circulation models

This study compared the historical simulations and future projections of precipitation and temperature of Coupled Model Intercomparison Project (CMIP)5 and CMIP6 general circulation models (GCMs) to quantify the differences in the projections due to differences in scenarios. Five performance indicators were used to quantify the model reproducibility of the observed precipitation levels at 22 stations for the historical period of 1970–2005. The percentages of change in precipitation and temperature were estimated for the near (2025–2060) and far future (2065–2100) for two Representative Concentration Pathway (RCP)4.5 and RCP8.5 scenarios of CMIP5 and two Shared Socioeconomic Pathway (SSP)2–4.5 and SSP5-8.5 scenarios of CMIP6. The uncertainty in the projection in each case was calculated using the reliability ensemble average (REA) method. As a result, the CMIP6 GCMs showed an improvement compared with the CMIP5 GCMs with regard to the ability to simulate the historical climate. The uncertainty in the precipitation projections was higher for SSPs than that in RCPs. With regard to the temperature, the uncertainty was higher for RCPs than for SSPs. The ensemble means of the precipitation and temperature showed higher changes in the far future compared with the near future for both RCPs and SSPs. This study contributes to improvement in the confidence of future projections using CMIP6 GCMs and bolsters our understanding of the relative uncertainty in SSPs and RCPs