Water Response of Upland Rice Varieties Adopted in Sub-Saharan Africa: A Water Application Experiment

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Shunsuke Matsumoto ◽  
Tatsushi Tsuboi
Keyword(s):  
Upland Rice ◽  
Sub Saharan Africa ◽  
Water Application ◽  
Rice Varieties ◽  
Sub Saharan ◽  
Water Response

scholarly journals Mechanistic understanding of iron toxicity tolerance in contrasting rice varieties from Africa: 2. Root oxidation ability and oxidative stress control

2020 ◽  
Vol 47 (2) ◽  
pp. 145
Author(s):  
Dorothy A. Onyango ◽  
Fredrickson Entila ◽  
James Egdane ◽  
Myrish Pacleb ◽  
Meggy Lou Katimbang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Sub Saharan Africa ◽  
Rice Varieties ◽  
Excess Iron ◽  
Improvement Programs ◽  
Sub Saharan ◽  
Breeding Efficiency ◽  
Biochemical Analyses ◽  
Fe Toxicity ◽  
And Control

To enhance breeding efficiency for iron (Fe) toxicity tolerance and boost lowland rice production in sub-Saharan Africa, we have characterised the morphological, physiological and biochemical responses of contrasting rice varieties to excess iron. Here, we report the capacity of four varieties (CK801 and Suakoko8 (tolerant), Supa and IR64 (sensitive)) to oxidise iron in the rhizosphere and control iron-induced oxidative stress. The experiments were conducted in hydroponic conditions using modified Magnavaca nutrient solution and 300 ppm of ferrous iron (Fe2+) supplied in the form of FeSO4. Severe oxidative stress was observed in sensitive varieties as revealed by their high levels of lipid peroxidation. Histochemical and biochemical analyses showed that tolerant varieties exhibited a better development of the aerenchyma and greater oxygen release than the sensitive varieties in response to excess Fe. Both suberin and lignin deposits were observed in the root, stem and leaf tissues but with varying intensities depending on the variety. Under iron toxic conditions, tolerant varieties displayed increased superoxide dismutase (SOD), glutathione reductase (GR), peroxidase (POX) and ascorbate peroxidase (APX) activities in both the roots and shoots, whereas sensitive varieties showed increased APX and catalase (CAT) activities in the roots. This study had revealed also that Suakoko8 mainly uses root oxidation to exclude Fe2+ from its rhizosphere, and CK801 possesses a strong reactive oxygen species scavenging system, in addition to root oxidation ability. Key traits associated with these tolerance mechanisms such as a well-developed aerenchyma, radial oxygen loss restricted to the root cap as well as strong activation of antioxidative enzymes (SOD, GR, POX and APX) could be useful selection criteria in rice varietal improvement programs for enhanced Fe toxicity tolerance.

scholarly journals Wheat (Triticum aestivum) Is Susceptible to the Parasitic Angiosperm Striga hermonthica, a Major Cereal Pathogen in Africa

2005 ◽  
Vol 95 (11) ◽  
pp. 1294-1300 ◽  
Author(s):  
R. A. Vasey ◽  
J. D. Scholes ◽  
M. C. Press
Keyword(s):  
Upland Rice ◽  
Global Climate ◽  
Subsequent Development ◽  
Biomass Accumulation ◽  
Sub Saharan Africa ◽  
Growth And Yield ◽  
Striga Hermonthica ◽  
Eastern Africa ◽  
Host Growth ◽  
Sub Saharan

Striga hermonthica is a parasitic weed endemic to sub-Saharan Africa. It most commonly parasitizes sorghum, maize, pearl millet, and upland rice, lowering yields and affecting the welfare of over 100 million people, principally subsistence farmers. Cereal crops with complete resistance to this pathogen have not been reported. In southern and eastern Africa, where Striga spp. are endemic, 5.6 million ha of wheat are cultivated annually. Despite this, there are only isolated field reports of wheat infected with Striga spp. It is not clear whether this is due to resistance in this cereal or to environmental factors. In this article, we examined the ability of root exudates from five cultivars of wheat (Chablis, Cadenza, Hereward, Riband, and Brigadier) to trigger germination of S. hermonthica seed. A study of the development of S. hermonthica on two cultivars of wheat (Hereward and Chablis) and on a range of ancestral relatives of wheat (Triticum and Aegilops spp.) then was conducted. Last, the effect of Striga spp. on host growth and yield was examined using wheat cv. Chablis and compared with that of a highly susceptible sorghum cultivar (CSH-1). Wheat was able to support the germination, attachment, and subsequent development of Striga spp. All wheat cultivars and ancestral species of modern wheat (Triticum and Aegilops spp.) were susceptible to S. hermonthica. In addition, in wheat, infection severely lowered plant height (-24%) and biomass accumulation (-33%); a small parasite biomass elicited a large host response. In conclusion, wheat is highly susceptible to S. hermonthica and, in light of global climate change, this may have implications for wheat-producing areas of Africa.

Weed management in upland rice in sub-Saharan Africa: impact on labor and crop productivity

Food Security ◽  
2014 ◽  
Vol 6 (3) ◽  
pp. 327-337 ◽  
Author(s):  
Philomena Ogwuike ◽  
Jonne Rodenburg ◽  
Aliou Diagne ◽  
Afiavi R. Agboh-Noameshie ◽  
Eyram Amovin-Assagba
Keyword(s):  
Weed Management ◽  
Upland Rice ◽  
Crop Productivity ◽  
Sub Saharan Africa ◽  
Sub Saharan

scholarly journals The role of biotechnology for agricultural sustainability in Africa

2007 ◽  
Vol 363 (1492) ◽  
pp. 905-913 ◽  
Author(s):  
Jennifer A Thomson
Keyword(s):  
Upland Rice ◽  
Agricultural Practices ◽  
Field Trials ◽  
Sub Saharan Africa ◽  
African Cassava Mosaic Virus ◽  
Streak Virus ◽  
Sweet Potatoes ◽  
Drought Tolerant ◽  
Resistant Varieties ◽  
Sub Saharan

Sub-Saharan Africa could have a shortfall of nearly 90 Mt of cereals by the year 2025 if current agricultural practices are maintained. Biotechnology is one of the ways to improve agricultural production. Insect-resistant varieties of maize and cotton suitable for the subcontinent have been identified as already having a significant impact. Virus-resistant crops are under development. These include maize resistant to the African endemic maize streak virus and cassava resistant to African cassava mosaic virus. Parasitic weeds such as Striga attack the roots of crops such as maize, millet, sorghum and upland rice. Field trials in Kenya using a variety of maize resistant to a herbicide have proven very successful. Drought-tolerant crops are also under development as are improved varieties of local African crops such as bananas, cassava, sorghum and sweet potatoes.

scholarly journals Closing Gender Gaps in Climate-Smart Agriculture through Strengthening Women Rice Seed Farmer’s Capacities and Access to Quality Stress-tolerant Seed in Benin

2021 ◽  
Vol 10 (3) ◽  
pp. 41
Author(s):  
Espérance Zossou ◽  
Afiavi R. Agboh-Noameshie ◽  
Alidou Assouma-Imorou
Keyword(s):  
Seed Production ◽  
Division Of Labour ◽  
Sub Saharan Africa ◽  
Rice Seed ◽  
Design Strategies ◽  
Rice Varieties ◽  
New Varieties ◽  
Sub Saharan ◽  
Smart Agriculture ◽  
And Control

Climate change and stress conditions (drought; submergence, salinity, iron toxicity, and cold) disproportionately affect the poorest and most disadvantaged rice farmers, forcing them deeper into poverty. Recent advances in genetics and breeding enable the development of rice varieties tolerant of these abiotic stresses and their cultivation can substantially contribute to poverty alleviation in unfavourable environments and for poor rice consumers globally. Through the program Stress-Tolerant Rice for Africa and South Asia (STRASA), fourteen new stress-tolerant varieties were released, produced and distributed in Sub-Saharan Africa to reach millions of poor farmers. However, ignoring women’s contributions to agriculture and particular in seed production and failing to design strategies to reach them with new varieties miss significant opportunities to reduce poverty. This study investigates on gender issues in rice seed production in Benin through a gender analysis of the division of labour, access and control of resources, livelihood, and constraints and opportunities faced. Both qualitative and quantitative data were collected with 29 women and 29 men seeds producers using both the Harvard Analytical and the Sustainable Livelihoods Frameworks. Data showed that women are central in rice seed production; but are marginalized in their access and control of resources. Given to women resources property rights as well as improving their control on resources will help them to be more performant as seed producers. These areas for action are important in designing and implementing activities in gender-responsive ways for sustainable Stress-Tolerant Rice seed multiplication, dissemination and out scaling in Africa.

Contribution of improved rice varieties to poverty reduction and food security in sub-Saharan Africa

2017 ◽  
Vol 14 ◽  
pp. 54-60 ◽  
Author(s):  
A. Arouna ◽  
J.C. Lokossou ◽  
M.C.S. Wopereis ◽  
S. Bruce-Oliver ◽  
H. Roy-Macauley
Keyword(s):  
Food Security ◽  
Poverty Reduction ◽  
Sub Saharan Africa ◽  
Rice Varieties ◽  
Sub Saharan

scholarly journals Genetic relationships between interspecific lines derived from Oryza glaberrima and Oryza sativa crosses using microsatellites and agro-morphological markers

2015 ◽  
Vol 13 (2) ◽  
pp. e0701 ◽  
Author(s):  
Yonnelle D. Moukoumbi ◽  
Olufisayo Kolade ◽  
Khady N. Drame ◽  
Moussa Sie ◽  
Marie Noelle Ndjiondjop
Keyword(s):  
Genetic Relationships ◽  
Rice Genome ◽  
Growth Conditions ◽  
Leaf Length ◽  
Sub Saharan Africa ◽  
Morphological Data ◽  
Oryza Glaberrima ◽  
Recurrent Parent ◽  
Rice Varieties ◽  
Sub Saharan

<p>New Rice(s) for Africa (NERICA) are high yielding rice varieties mostly cultivated in Sub-Saharan Africa and developed by the Africa Rice Center. This study is aimed at investigating the proportion of introgression of parental genomic contribution of 60 lowland NERICA varieties and establishment of molecular profiling. Agro-morphological data from 17 characteristics was recorded and significant (<em>p</em>&lt;0.05) to high significant (<em>p</em>&lt;0.0001) differences were obtained with leaf length and width, plant height at maturity, days to heading, maturity, primary and secondary branching of panicles, and grain width and grain thickness. A total of 114 microsatellite polymorphic markers covering 2183.13 cM of the rice genome showed the proportions of alleles introgressed from the donor parent (<em>Oryza glaberrima</em>) into 52 lowland NERICA lines (TOG5681 and IR64)<em> </em>as follows: 11% for BC<sub>2</sub>, 6.07% for BC<sub>3, </sub>and 7.55% for BC<sub>4</sub>. The introgression proportions for the eight remaining lowland NERICA lines derived from other crosses ranged from 5.5 to 11.3%. The proportion recorded with the recurrent parent was 83.99%. The highest introgression proportions of the <em>O. glaberrima </em>allele for all 60 lowland NERICA lines were found on chromosomes 2, 6 and 12 (TOG5681/IR64) and on chromosome 3 with NERIC-L-29 (TOG5681/IR1529-680-3-2). Multivariate analyses performed using an association of agro-morphological and molecular data revealed two major groups according to the distribution of the lowland NERICAs including the lowland NERICAs released were found in cluster 1 of the dendrogram. Genetic and genomic studies, QTL identification and analysis using agro-morphologically significant traits revealed should be used to develop mega-varieties adapted in rice growth conditions in Sub-Saharan Africa.</p>

RTS,S/AS01, a vaccine targeting pre-erythrocytic stages of Plasmodium falciparum

2017 ◽  
Vol 1 (6) ◽  
pp. 533-537
Author(s):  
Lorenz von Seidlein ◽  
Borimas Hanboonkunupakarn ◽  
Podjanee Jittmala ◽  
Sasithon Pukrittayakamee
Keyword(s):  
Protective Efficacy ◽  
Age Groups ◽  
Sub Saharan Africa ◽  
Phase Iii ◽  
European Medicines Agency ◽  
Older Children ◽  
Pivotal Phase ◽  
Malaria Epidemiology ◽  
Maximum Benefit ◽  
Sub Saharan

RTS,S/AS01 is the most advanced vaccine to prevent malaria. It is safe and moderately effective. A large pivotal phase III trial in over 15 000 young children in sub-Saharan Africa completed in 2014 showed that the vaccine could protect around one-third of children (aged 5–17 months) and one-fourth of infants (aged 6–12 weeks) from uncomplicated falciparum malaria. The European Medicines Agency approved licensing and programmatic roll-out of the RTSS vaccine in malaria endemic countries in sub-Saharan Africa. WHO is planning further studies in a large Malaria Vaccine Implementation Programme, in more than 400 000 young African children. With the changing malaria epidemiology in Africa resulting in older children at risk, alternative modes of employment are under evaluation, for example the use of RTS,S/AS01 in older children as part of seasonal malaria prophylaxis. Another strategy is combining mass drug administrations with mass vaccine campaigns for all age groups in regional malaria elimination campaigns. A phase II trial is ongoing to evaluate the safety and immunogenicity of the RTSS in combination with antimalarial drugs in Thailand. Such novel approaches aim to extract the maximum benefit from the well-documented, short-lasting protective efficacy of RTS,S/AS01.

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