10 research outputs found
GENETIC ANALYSIS OF YIELD AND YIELD COMPONENTS IN Oryza sativa x Oryza sativa CROSS
The number one goal of most rice improvement programmes around the
world is breeding for high potential to take care of the increasing
consumption of rice. The objective of this experiment was to study the
inheritance of yield and yield components and to estimate the
heritabilities of important quantitative traits in rice (Oryza sativa
L.). Six generations viz., P1, P2, F1, F2, BCP1 and BCP2 of a cross
between IET6279 and IR70445-146-3-3 were used for the study. Generation
mean analysis suggested that additive effects had a major role for the
expression of plant height, number of panicles, number of spikelets per
panicle, percentage spikelets fertility per plant and grain yield per
plant, which further suggested that phenotypic selection was possible
at an early stage. Both additive and non-additive gene actions were
important for the expression of number of fertile spikelets per panicle
and 100-grain weight. Therefore, selection for these characters would
be fruitful, if delayed till epistasis effects are reduced to a
minimum. High broad sense heritability estimates were observed for
characters viz. plant height and 100-grain weight, suggesting that the
characters under study are less influenced by environment in their
expression. Thus, selection based on phenotypic value of these
characters would be reliable and effective. Low estimates of broad
sense heritability were observed for number of panicles per plant,
number of spikelets per panicle, number of fertile spikelets per
panicle, percentage spikelets fertility per plant and grain yield per
plant, indicating that influence of the environment was high for these
characters. Therefore, superior genotypes selection based on phenotypic
performance for these characters may not effective.La majorit\ue9 des objectifs des programmes d\u2019am\ue9lioration
du riz dans le monde est relative \ue0 la s\ue9lection pour le
d\ue9sire croissant de la consommation du riz. L\u2019objectif de
cette exp\ue9rimentation \ue9tait d\u2019\ue9tudier
l\u2019h\ue9ritage du rendement et des composantes du rendement et
d\u2019estimer les h\ue9ritabilit\ue9s des traits importants sur
le riz (Oryza sativa L.). Six g\ue9n\ue9rations viz, P1, P2, F1,
F2, BCP1 et BCP2 du croisement entre IET6279 et IR70445-146-3-3
\ue9taient utilis\ue9s pour cette \ue9tude. L\u2019analyse de la
moyenne des g\ue9n\ue9rations a sugg\ue9r\ue9 que les effets
additifs ont un r\uf4le majeur pour l\u2019expression de la taille
de la plante, le nombre de panicules, le nombre d\u2019\ue9pillets
par panicule, le pourcentage de fertilit\ue9 d\u2019\ue9pillets
par plant et le rendement en grain par plant qui davantage ont
sugg\ue9r\ue9 que la s\ue9lection ph\ue9notypique \ue9tait
possible \ue0 une \ue9tape pr\ue9coce. Les actions de g\ue8nes
de type additifs et non-additifs \ue9taient importantes pour
l\u2019expression du nombre d\u2019\ue9pillets fertiles par
panicule et le poids de 100-grains. Toutefois, la s\ue9lection pour
ces caract\ue8res serait utile\ua0; si elle est retard\ue9e
jusqu\u2019\ue0 ce que les effets d\u2019\ue9pistasis soit
r\ue9duits au minimum. La valeur \ue9lev\ue9e de la grande
h\ue9ritabilit\ue9 \ue9tait observ\ue9e pour les
caract\ue8res viz. La taille de la plante et le poids de 100 grains,
sugg\ue9raient que les caract\ue8res sous investigation sont moins
influenc\ue9s par l\u2019environnement dans leur expression. Donc,
la s\ue9lection bas\ue9e sur les valeurs ph\ue9notypiques de ces
caract\ue8res serait plus efficace. De faibles valeurs estim\ue9es
de la grande h\ue9ritabilit\ue9 \ue9taient observ\ue9es pour le
nombre panicules par plant, nombre d\u2019\ue9pillets par panicule,
nombre d\u2019\ue9pillets fertiles par panicule, le pourcentage
d\u2019\ue9pillets fertiles par plant et le rendement en grain par
plant, indiquant que l\u2019influence de l\u2019environnement
\ue9tait \ue9lev\ue9e pour ces caract\ue8res. Toutefois, la
s\ue9lection sup\ue9rieure des g\ue9notypes bas\ue9e sur la
performance ph\ue9notypique pour ces caract\ue8res pourrait
\ueatre non efficiente
Identification of QTLs for grain yield and other traits in tropical maize under high and low soil-nitrogen environments.
Article purchased; Published online: 03 Nov 2017Low soil Nitrogen (low-N) is one of the most important abiotic stresses responsible for significant yield losses in maize (Zea mays. L.). The development and commercialization of low N tolerant genotypes can contribute to improved food security in developing countries. However, selection for low N tolerance is difficult because it is a complex trait with strong interaction between genotypes and environments. Marker assisted breeding holds great promise for improving such complex traits more efficiently in less time, but requires markers associated with the trait of interest. In this study, 150 BC2F1 families of CML 444 x CML 494 were evaluated at two location for two consecutive seasons to identify SNP markers associated with quantitative trait loci (QTLs) for yield and other agronomic traits under low- and high-N environments. A total of 13 QTLs were identified with 158 SNP markers, of which nine and four QTLs were detected under low- and high-N environments, respectively. Five QTLs one each for grain yield (qgy-1), days to silking (qdts-1) and anthesis- silking interval (qasi-6), and two for stay green characteristic (qsg-1 and qsg-4) were close to their adjacent markers, with an interval of 0.7 to 5.2 cM between them and explained phenotypic variance of 9 to 21%. These QTLs would be invaluable for rapid introgression of genomic regions into maize populations using marker assisted selection (MAS) approaches. However, further validation of these QTLs is needed before use in MAS
Repurposing an integrated national influenza platform for genomic surveillance of SARS-CoV-2 in Ghana: a molecular epidemiological analysis
Background
Genomic surveillance of SARS-CoV-2 is crucial for monitoring the spread of COVID-19 and guiding public health decisions, but the capacity for SARS-CoV-2 testing and sequencing in Africa is low. We integrated SARS-CoV-2 surveillance into an existing influenza surveillance network with the aim of providing insights into SARS-CoV-2 transmission and genomics in Ghana.
Methods
In this molecular epidemiological analysis, which is part of a wider multifaceted prospective observational study, we collected national SARS-CoV-2 test data from 35 sites across 16 regions in Ghana from Sept 1, 2020, to Nov 30, 2021, via the Ghanaian integrated influenza and SARS-CoV-2 surveillance network. SARS-CoV-2-positive samples collected through this integrated national influenza surveillance network and from international travellers arriving in Accra were sequenced with Oxford Nanopore Technology sequencing and the ARTIC tiled amplicon method. The sequence lineages were typed with pangolin and the phylogenetic analysis was conducted with IQ-Tree2 and TreeTime.
Findings
During the study period, 5495 samples were submitted for diagnostic testing through the national influenza surveillance network (2121 [46·1%] of 4021 samples with complete demographic data were from female individuals and 2479 [53·9%] of 4021 samples were from male individuals). We also obtained 2289 samples from travellers who arrived in Accra and had a positive lateral flow test, of whom 1626 (71·0%, 95% CI 69·1–72·9) were confirmed to be SARS-CoV-2 positive. Co-circulation of influenza and SARS-CoV-2 in Ghana was detected, with increased cases of influenza in November, 2020, November, 2021, and January and June, 2021. In 4124 samples from individuals with influenza-like illness, SARS-CoV-2 was identified in 583 (14·1%, 95% CI 13·1–15·2) samples and influenza in 356 (8·6%, 7·8–9·5). Conversely, in 476 samples from individuals with of severe acute respiratory illness, SARS-CoV-2 was detected in 58 (12·2%, 9·5–15·5) samples and influenza in 95 (19·9%, 16·5–23·9). We detected four waves of SARS-CoV-2 infections in Ghana; each wave was driven by a different variant: B.1 and B.1.1 were the most prevalent lineages in wave 1, alpha (B.1.1.7) was responsible for wave 2, delta (B.1.617.2) and its sublineages (closely related to delta genomes from India) were responsible for wave 3, and omicron variants were responsible for wave 4. We detected omicron variants among 47 (32%) of 145 samples from travellers during the start of the omicron spread in Ghana (wave 4).
Interpretation
This study shows the value of repurposing existing influenza surveillance platforms to monitor SARS-CoV-2. Influenza continued to circulate in Ghana in 2020 and 2021, and remained a major cause of severe acute respiratory illness. We detected importations of SARS-CoV-2 variants into Ghana, including those that did or did not lead to onward community transmission. Investment in strengthening national influenza surveillance platforms in low-income and middle-income countries has potential for ongoing monitoring of SARS-CoV-2 and future pandemics.
Funding
The EDCTP2 programme supported by the EU
Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017
A double burden of malnutrition occurs when individuals, household members or communities experience both undernutrition and overweight. Here, we show geospatial estimates of overweight and wasting prevalence among children under 5 years of age in 105 low- and middle-income countries (LMICs) from 2000 to 2017 and aggregate these to policy-relevant administrative units. Wasting decreased overall across LMICs between 2000 and 2017, from 8.4 (62.3 (55.1�70.8) million) to 6.4 (58.3 (47.6�70.7) million), but is predicted to remain above the World Health Organization�s Global Nutrition Target of <5 in over half of LMICs by 2025. Prevalence of overweight increased from 5.2 (30 (22.8�38.5) million) in 2000 to 6.0 (55.5 (44.8�67.9) million) children aged under 5 years in 2017. Areas most affected by double burden of malnutrition were located in Indonesia, Thailand, southeastern China, Botswana, Cameroon and central Nigeria. Our estimates provide a new perspective to researchers, policy makers and public health agencies in their efforts to address this global childhood syndemic. © 2020, The Author(s)
Author Correction: Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017 (Nature Medicine, (2020), 26, 5, (750-759), 10.1038/s41591-020-0807-6)
An amendment to this paper has been published and can be accessed via a link at the top of the paper. © 2020, The Author(s)
Author Correction: Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017 (Nature Medicine, (2020), 26, 5, (750-759), 10.1038/s41591-020-0807-6)
An amendment to this paper has been published and can be accessed via a link at the top of the paper. © 2020, The Author(s)
Innovation platform: A tool for sustainable rice production in Ghana
Agriculture plays a key role in Ghana's economy and that of sub Saharan Africa. Transforming agriculture in Ghana is key to increasing farm output, reducing poverty, ensuring environmental sustainability and reducing food insecurity. Linear transfer of technology addressing productivity, marketing and policy underlies the poor performance of the rice sector hence the need for the Innovation Systems Approach using the Innovation Platform which is a coalition of actors along the value chain as a key tool. Rice is the second most important cereal after maize in Ghana and is fast becoming a cash crop. Rice production and the area cropped are increasing but national annual average yield has remained low, at 2.5 tons/hectare. Despite the enabling prevailing policy environment, local rice production still falls short of local demand hence rice importation is very high, valued at US$500 million annually. To reduce the rice demand deficit in Ghana, four Innovation platforms were established in Atebubu, Amantin (Feed the future), Jasikan and Weta (Systems of Rice intensification). A total of 265 actors were involved in the study. Farmer constraints identified included high cost of agro chemicals and fertilizer, unreliable rainfall patterns/lack of irrigational facilities, low farm gate prices, high incidence of weeds on rice farm and low yielding rice varieties. Key roles of innovation platforms in increasing rice productivity in Ghana are identifying the main bottlenecks in the rice value chain, creating room for some of the challenges to be addressed upfront, creating a united front for advancing and affecting policy, quality rice for the domestic and international markets and linking actors to financial institutions. The requirements to ensure that the full potential of rice resource in Ghana are achieved lie in pulling all efforts at the various stages of the rice value chain together to serve as an attraction pool for strong policies and national aid. Keywords: Rice, Value chain, Innovation system, Innovation platform La Plate-forme d'innovation: un outil pour une production durable du riz au Ghana L'agriculture joue un rôle clé dans l'économie du Ghana et celle de l'Afrique subsaharienne. La transformation de l'agriculture au Ghana est essentielle pour accroître la production agricole, réduire la pauvreté, assurer la durabilité environnementale et réduire l'insécurité alimentaire. Le transfert linéaire de technologie traitant de la productivité, du marketing et de la politique sous-tend la mauvaise performance du secteur du riz, d'où la nécessité de l'approche des systèmes d'innovation en utilisant la plate-forme d'innovation qui est une coalition d'acteurs de la chaîne de valeur en tant qu'outil clé. Le riz est la deuxième céréale la plus importante après le maïs au Ghana et devient rapidement une culture de rapport. La production de riz et la superficie cultivée augmentent, mais le rendement moyen annuel national est resté faible, à 2,5 tonnes/hectare. En dépit de l'environnement politique favorable, la production locale de riz est toujours inférieure à la demande locale, de sorte que l'importation du riz est très élevée à 500 millions de dollars par an. Pour réduire le déficit de demande du riz au Ghana, quatre plates-formes d'innovation ont été créées à Atebubu, Amantin (Nourrir les futur 'Feed the future'en anglais), Jasikan et Weta (Systèmes d'intensification du riz). Un total de 265 acteurs ont été impliqués dans l'étude. Les contraintes des agriculteurs identifiés comprenaient un coût élevé des agro-produits agro- chimiques et des engrais, des précipitations peu fiables/un manque d'installations d'irrigation, des prix bas de la ferme, une forte incidence de mauvaises herbes sur les fermes de riz et le rendement faible des variétés du riz. Les rôles clés des plates-formes d'innovation dans l'augmentation de la productivité du riz au Ghana ont permis d'identifier les principaux goulets d'étranglement de la chaîne de valeur du riz, créant ainsi certains défis à relever, créant un front uni pour faire avancer et affecter les politiques, le riz de qualité pour le marché domestique et international et reliant les acteurs aux institutions financières. Les exigences visant à garantir que le plein potentiel de la ressource du riz au Ghana réside dans l'effort consistant à attirer tous les efforts aux différentes étapes de la chaîne de valeur du riz pour servir comme un pool d'attraction pour des politiques solides et des aides nationales. Mots-clés: le Riz, chaîne de valeur, système d'innovation, la plate-forme d'innovatio
Global injury morbidity and mortality from 1990 to 2017: Results from the global burden of disease study 2017
Background Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. methods We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ
Author Correction: Mapping local patterns of childhood overweight and wasting in low- and middle-income countries between 2000 and 2017 (Nature Medicine, (2020), 26, 5, (750-759), 10.1038/s41591-020-0807-6)
An amendment to this paper has been published and can be accessed via a link at the top of the paper. © 2020, The Author(s)