scholarly journals Breeding maize ( Zea mays ) for Striga resistance: Past, current and prospects in sub‐saharan africa

2021 ◽  
Author(s):  
Abdoul‐Madjidou Yacoubou ◽  
Nouhoun Zoumarou Wallis ◽  
Abebe Menkir ◽  
Valerien A. Zinsou ◽  
Alexis Onzo ◽  
...  
Keyword(s):  
Zea Mays ◽  
Sub Saharan Africa ◽  
Striga Resistance ◽  
Sub Saharan

scholarly journals Transcriptomic Analysis of a Susceptible African Maize Line to Fusarium verticillioides Infection

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1112
Author(s):  
Humaira Lambarey ◽  
Naadirah Moola ◽  
Amy Veenstra ◽  
Shane Murray ◽  
Mohamed Suhail Rafudeen
Keyword(s):  
Zea Mays ◽  
Fusarium Verticillioides ◽  
Morphological Characteristics ◽  
Sub Saharan Africa ◽  
Chemical Stimulus ◽  
Post Inoculation ◽  
Rna Seq ◽  
Ear Rot ◽  
Maize Line ◽  
Sub Saharan

Maize (Zea mays L.) is a staple crop providing food security to millions of people in sub Saharan Africa. Fusarium verticillioides, an important fungal pathogen, infects maize causing ‘Fusarium Ear Rot’ disease, which decreases maize kernel yield and the quality of the crop harvested. Currently, no African maize line is completely resistant to infection by F. verticillioides. This study investigated an African maize line, Zea mays CML144, infected with F. verticillioides. Analysis of morphological characteristics showed significant differences between mock-infected and infected plants. RNA-sequencing (RNA-seq) was conducted on plants 14 days post-inoculation to identify differentially expressed genes (DEGs) involved in F. verticillioides infection. Analysis of RNA-seq data revealed DEGs that were both significantly up- and down-regulated in the infected samples compared to the mock-infected control. The maize TPS1 and cytochrome P450 genes were up-regulated, suggesting that kauralexins were involved in the CML144 defense response. This was substantiated by kauralexin analyses, which showed that kauralexins, belonging to class A and B, accumulated in infected maize tissue. Gene ontology terms relating to response to stimulus, chemical stimulus and carbohydrate metabolic processes were enriched, and the genes belonging to these GO-terms were down-regulated. Quantitative real-time PCR was performed on selected DEGs and measurement of phytoalexin accumulation validated the RNA-seq data and GO-analysis results. A comparison of DEGs from this study to DEGs found in F. verticillioides (ITEM 1744) infected susceptible (CO354) and resistant (CO441) maize genotypes in a previous study, matched 18 DEGs with 17 up-regulated and one down-regulated, respectively. This is the first transcriptomic study on the African maize line, CML144, in response to F. verticillioides infection.

scholarly journals Incidence of fungi and aflatoxin contamination of maize in Tolon-Kumbungu district of Ghana

2020 ◽  
Vol 28 (2) ◽  
pp. 195-202
Author(s):  
E.K. Aklaku ◽  
E.N.K. Sowley ◽  
M. Ofosu
Keyword(s):  
Zea Mays ◽  
Agar Plate ◽  
Sampling Technique ◽  
Northern Region ◽  
Aflatoxin Contamination ◽  
Sub Saharan Africa ◽  
Rapid Screening ◽  
Food And Agriculture ◽  
Aflatoxigenic Fungi ◽  
Sub Saharan

Maize (Zea mays L.) is an important staple food crop and a source of income to farmers, as well as foreign exchange earner in most countries in sub-Saharan Africa. Its production is hampered by fungal diseases, which also cause contamination with mycotoxins, especially aflatoxin and its associated health hazards. This study sought to isolate and identify aflatoxigenic fungi, as well as detect the presence of Aflatoxin B1 (AfB1) in maize samples obtained from farmers in the Tolon-Kumbungu district in the northern region of Ghana. Twenty farming communities were randomly selected for the study in consultation with the district office of the Ministry of Food and Agriculture (MoFA). Samples were collected from 200 randomly selected maize farmers by the composite sampling technique, for isolation of aflatoxigenic fungi by the agar plate method and the detection of aflatoxin. Aflatoxin was detected in maize samples with the Black light, rapid screening and immunoassay methods. Aspergillus flavus had the highest percentage of occurrence (63.7%); followed by A. niger (16.5%), Rhizopus stolonifer (9.3%), Penicillium spp. (6.9%) and Fusarium oxysporum (3.7%). Farm samples had more aflatoxin than those from stores and markets. Samples of maize from farms in Gbirimani community had the highest aflatoxin contamination of +60 ppb. Concentrations of Afb1 at or above +20 ppb were recorded in all the communities, except in Tinguli. Apart from Voggu, all market samples were free from aflatoxin contamination. Key words: Aflatoxigenic fungi, postharvest, Zea mays

scholarly journals Identification of QTLs Controlling Resistance/Tolerance to Striga hermonthica in an Extra-Early Maturing Yellow Maize Population

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1168 ◽  
Author(s):  
Baffour Badu-Apraku ◽  
Samuel Adewale ◽  
Agre Paterne ◽  
Melaku Gedil ◽  
Robert Asiedu
Keyword(s):  
Candidate Genes ◽  
Marker Assisted Selection ◽  
Defense Mechanisms ◽  
Sub Saharan Africa ◽  
Striga Hermonthica ◽  
Maize Production ◽  
Maize Population ◽  
Striga Resistance ◽  
Sub Saharan ◽  
Indicator Traits

Striga hermonthica parasitism is a major constraint to maize production in sub-Saharan Africa with yield losses reaching 100% under severe infestation. The application of marker-assisted selection is highly promising for accelerating breeding for Striga resistance/tolerance in maize but requires the identification of quantitative trait loci (QTLs) linked to Striga resistance/tolerance traits. In the present study, 194 F2:3 families of TZEEI 79 × TZdEEI 11 were screened at two Striga-endemic locations in Nigeria, to identify QTLs associated with S. hermonthica resistance/tolerance and underlying putative candidate genes. A genetic map was constructed using 1139 filtered DArTseq markers distributed across the 10 maize chromosomes, covering 2016 cM, with mean genetic distance of 1.70 cM. Twelve minor and major QTLs were identified for four Striga resistance/tolerance adaptive traits, explaining 19.4%, 34.9%, 14.2% and 3.2% of observed phenotypic variation for grain yield, ears per plant, Striga damage and emerged Striga plants, respectively. The QTLs were found to be linked to candidate genes which may be associated with plant defense mechanisms in S. hermonthica infested environments. The results of this study provide insights into the genetic architecture of S. hermonthica resistance/tolerance indicator traits which could be employed for marker-assisted selection to accelerate efficient transfer host plant resistance genes to susceptible genotypes.

scholarly journals Enhancement of proline content and antioxidant enzyme activities induced by drought stress in maize (Zea mays L.) by application of compost

2020 ◽  
Vol 13 (7) ◽  
pp. 2978-2990
Author(s):  
Atalaèsso Bokobana ◽  
Outendé Toundou ◽  
Komi Odah ◽  
Koffi S.S. Dossou ◽  
Koffi Tozo
Keyword(s):  
Zea Mays ◽  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Water Deficit ◽  
Sandy Soil ◽  
Zea Mays L ◽  
Proline Content ◽  
Sub Saharan Africa ◽  
Antioxidant Enzyme Activities ◽  
Sub Saharan

In sub-Saharan Africa, soil degradation and recurrent droughts are major obstacles to a sustainable agriculture. This study aimed at investigating the effect of compost addition to soil on proline content and activities of the antioxidant enzymes [catalase (CAT), ascorbate peroxidase (APX)] in maize plants, under drought stress conditions. The test was carried out in 20L plastic pots containing either sandy soil or sandy soil with the fertilizer, under natural conditions. The water deficit was induced at male blooming and milky grain stages. Plant irrigation was done by successive weighing of the pots during which the control is reduced to the same weight corresponding to 70% of the useful water reserve (UWR), while the stressed treatment maintains the water content at 30% of the UWR for 10 days. At the end of the stress period, the proline content, the CAT and APX activities in the leaves were determined through a spectrophotometry. The results show an important accumulation of proline and increase in enzymatic activity induced by water deficit in plants grown on compost (p = 0.00000 at p < 0.05). This study provides evidence for a beneficial effect of compost application in enhancing drought tolerance of maize.Keywords: Drought stress; compost; proline; antioxidant enzymes; Zea mays L.

scholarly journals Identifying heterotic groups and testers for hybrid development in early maturing yellow maize ( Zea mays ) for sub‐Saharan Africa

2020 ◽  
Vol 139 (4) ◽  
pp. 708-716 ◽  
Author(s):  
Benjamin Annor ◽  
Baffour Badu‐Apraku ◽  
Daniel Nyadanu ◽  
Richard Akromah ◽  
Morakinyo A. B. Fakorede
Keyword(s):  
Zea Mays ◽  
Sub Saharan Africa ◽  
Heterotic Groups ◽  
Early Maturing ◽  
Sub Saharan ◽  
Hybrid Development

scholarly journals INTROGRESSION OF STRIGA RESISTANCE INTO POPULAR SUDANESE SORGHUM VARIETIES USING MARKER ASSISTED SELECTION

2016 ◽  
Vol 1 (1) ◽  
pp. 49 ◽  
Author(s):  
Rasha Ali ◽  
Charles T. Hash ◽  
Odeny Damaris ◽  
Adil Elhussein ◽  
Abdalla H. Mohamed
Keyword(s):  
Marker Assisted Selection ◽  
Integrated Management ◽  
Management Strategies ◽  
Sub Saharan Africa ◽  
Effective Control ◽  
Progress Curve ◽  
Striga Resistance ◽  
Infested Field ◽  
Backcross Populations ◽  
Sub Saharan

Witchweed (Strigas spp.) is one of the most important cereals production constraints globally and is projected to worsen with anticipated climate change. It is especially a devastating parasitic weed in Sub-Saharan Africa and parts of Asia. Integrated management strategies that depend mainly on host plant resistance provide the most effective control mechanism for Striga. We used molecular marker-assisted backcrossing to introgress Striga resistance from a resistant genotype, N13, into agronomically important genetic backgrounds (Tabat and Wad Ahmed). Backcross populations BC3S3 were generated and genotyped using Simple Sequence Repeat (SSR) and Diversity Arrays Technology (DArT) markers. A total of 17 promising backcross progenies were selected and screened in Striga infested field alongside their parents. The Area Under Striga Progress Curve (AUSPC) showed significant decrease in Striga count (920-7.5) resulting in a 97-189% increase in yield under Striga pressure. Our results demonstrate the practical application of marker assisted selection (MAS) to generate farmer-preferrd Striga resistant lines in Sudan.

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.

Mortality and Society in Sub-Saharan Africa

1993 ◽  
Vol 47 (3) ◽  
pp. 555-556
Author(s):  
Lado Ruzicka
Keyword(s):  
Sub Saharan Africa ◽  
Sub Saharan
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