62 research outputs found
Occurrence of Banana bunchy top virus in banana and plantain (Musa sp.) in Benin
In July 2011, banana and plantain that displayed stunting and leaf symptoms typical of banana bunchy top disease were observed to be widespread in Dangbo Commune, Ouémé Department, Benin. To identify the cause of the disease, a roving survey was conducted in December 2011 in nine locations in Avrankou, Dangbo, Akpro-Missérété and Porto-Novo Communes, in Ouémé. In each location, the incidence of symptom-bearing plants was estimated from counts of 15 mats, and samples were collected for Banana bunchy top virus (BBTV) assessment. Approximately 60% of the 94 banana mats assessed had plants exhibiting typical symptoms of BBTV infection - chlorotic leaf margins, dark green streaks on petioles, narrow leaves that bunched at the top, and severe stunting. Total DNA was extracted from 25 leaf samples collected from plants with symptoms; they were then tested for BBTV by polymerase chain reaction. The sequences showed 100% nucleotide sequence identity with a BBTV isolate from Cameroon (FJ580970) and 99-100% identity with several other BBTV isolates from the GenBank database belonging to the South Pacific group, which consisted of BBTV isolates from Africa, Australia, India and South Pacific. This finding confirmed that the virus isolate associated with the diseased plants in Benin was of the BBTV South Pacific type. This is thought to be the first report of BBTV in Benin. The disease is widespread in all the four communes surveyed
New foci of Rhipicephalus microplus in West Africa
The invasive character of Rhipicephalus microplus was observed in Benin, the
second West-African country from which this ticks species has been collected after the
initial confirmed record in Ivory Coast in 2007. A cross-sectional study was carried out in
the Department of Mono to examine the presence of the tick R. microplus. The survey
covered 9 herds (villages) in an agro-ecological zone inhabited by agro-pastoralists,
including the State Farm of Kpinnou that imported Girolando cattle from Brazil. Almost
800 ticks were sampled from 36 cattle, on average four cattle per village. The morphological
identification revealed ticks of two different genera: Rhipicephalus and Amblyomma.
Rhipicephalus microplus was the only representative of the species previously
known as Boophilus or blue ticks. Its taxonomic identity was confirmed molecularly by
PCRâRFLP. A comparison was made with the situation of R. microplus in Brazil.The Belgian Development Cooperation (BDC) for the
financial support of this research project as part of a Masters programme offered by the Institute of Tropical
Medicine in Antwerp, Belgium.http://www.springerlink.com/content/100158/ab201
ViabilitĂ© et performance de germination des semences de Acacia auriculiformis A. Cunn. ex Benth. (Fabaceae) issues du sol de la forĂȘt classĂ©e de Pahou (Sud BĂ©nin)
La rĂ©colte des semences de Acacia auriculiformis devient trĂšs difficile lorsque lâarbre prend de lâĂąge. Cette Ă©tude a Ă©valuĂ© la viabilitĂ© et la performance de germination des semences de cette espĂšce Ă©ventuellement conservĂ©es dans le sol. Ă cet effet, une expĂ©rimentation a Ă©tĂ© faite sur une pĂ©riode de sept semaines pour dĂ©nombrer le nombre de plantules en Ă©mergence Ă partir des Ă©chantillons composites de sol collectĂ©s dans une vieille plantation de Acacia auriculiformis au Sud BĂ©nin. LâĂ©chantillonnage est stratifiĂ©, alĂ©atoire sur le plan horizontal (provenance), mais systĂ©matique sur le plan vertical (profondeur). Les Ă©chantillons ont Ă©tĂ© mis en conditions minimales de germination. La mĂ©thode de germination a Ă©tĂ© utilisĂ©e pour Ă©valuer la viabilitĂ© et la performance de germination des semences. LâindĂ©pendance de ces paramĂštres vis-Ă -vis des facteurs considĂ©rĂ©s a Ă©tĂ© testĂ©e avec Khi-2. Enfin, les tendances observĂ©es ont Ă©tĂ© expliquĂ©es par les modĂšles GLM. La profondeur et la provenance se rĂ©vĂšlent avoir des influences significatives sur les paramĂštres mesurĂ©s. Le sol de la plantation peut contenir jusquâĂ 267 semences viables de Acacia auriculiformis par mÂČ surtout Ă lâintĂ©rieur de la plantation dans la premiĂšre couche du sol. Il est possible de faire recours Ă ces semences du sol pour pallier les difficultĂ©s liĂ©es Ă lâapprovisionnement en plants au BĂ©nin.The harvest of the seeds of Acacia auriculiformis becomes very difficult when the tree gets older. This study has assessed the viability, and the germination performance of the speciesâ seeds eventually conserved in the soil. For this purpose, an experiment was carried out over a period of seven weeks to count the number of seedlings emerging from the composite soil samples collected in an old plantation of Acacia auriculiformis in South Benin. Samples were randomly collected over a horizontally stratified scale (provenance), but systematically collected over a vertically stratified scale (depth). The samples have been set to minimum conditions of germination. Germination method was used to assess the viability and the germination performance of seeds. The independence of those parameters with regard to considered factors was tested with Khi-2. Finally, GLM models were used to explain the recorded trends. Depth and provenance seem both to significantly influence assessed parameters. Soil from the plantation can hold up to 267 viable seeds of Acacia auriculiformis per mÂČ especially inside the plantation in the first layer of the ground. It is possible to rely on those soilâs seeds to alleviate the difficulties related to seedling supply in Benin
Differential household vulnerability to climatic and non-climatic stressors in semi-arid areas of Mali, West Africa
Semi-Arid Regions (SARs) of West Africa are considered climate change âhotspotsâ where strong
ecological, economic and social impacts converge to make socio-ecological systems particularly
vulnerable. While both climatic and non-climatic drivers interact across scales to influence
vulnerability, traditionally, this inter-connectedness has received little attention in vulnerability
assessments in the region. This study adopted the vulnerability patterns framework, operationalized
using the Multidimensional Livelihood Vulnerability approach to include both climatic and nonclimatic
stressors to analyze differential household vulnerability in SARs of Mali. Findings showed that
while drought was the most mentioned climate-related stressor, households were also exposed to a
diversity of environmental and socio-economic stressors, including food scarcity, livestock disease,
labour unavailability, crop damage, and erratic rainfall patterns. The typology revealed three
vulnerability archetypes differentiated by adaptive capacity and sensitivity. Availability of productive
household members, household resource endowments, livelihood diversification and social networks
were the main discriminant factors of household adaptive capacity, while challenges relating to food
and water security make households more sensitive to stressors. The analysis highlighted the
heterogeneity in household vulnerability patterns within and across communities. Failing to account
for this heterogeneity in adaptation planning might result in a mismatch between adaptation needs
and interventions, and potentially in maladaptation
Surgical Task Shifting in Sub-Saharan Africa
Kathryn Chu and colleagues discuss some of the experiences of surgical task shifting to date, and outline lessons from task shifting in the delivery of HIV/AIDS care
Cell entry of a host targeting protein of oomycetes requires gp96
This work is supported by the [European Communityâs] Seventh Framework Programme [FP7/2007â2013] under grant agreement no. [238550] (L.L., J.D.-U., C.J.S., P.v.W.); BBSRC [BBE007120/1, BB/J018333/1 and BB/G012075/1] (F.T., I.d.B., C.J.S., S.W., P.v.W.); Newton Global Partnership Award [BB/N005058/1] (F.T., P.v.W.), the University of Aberdeen (A.D.T., T.R., C.J.S., P.v.W.) and Deutsche Forschungsgemeinschaft [CRC1093] (P.B., T.S.). We would like to acknowledge the Ministry of Higher Education Malaysia for funding INA. We would like to thank Brian Haas for his bioinformatics support. We would like to acknowledge Neil Gow and Johannes van den Boom for critical reading of the manuscript. We would like to acknowledge Svetlana Rezinciuc for technical help with pH-studies.Peer reviewedPublisher PD
Accelerated cloning of a potato late blightâresistance gene using RenSeq and SMRT sequencing
Global yields of potato and tomato crops are reduced owing to potato late blight disease, which is caused by Phytophthora infestans. Although most commercial potato varieties are susceptible to blight, wild potato relatives are not and are therefore a potential source of Resistance to P. infestans (Rpi) genes. Resistance breeding has exploited Rpi genes from closely related tuber-bearing potato relatives, but is laborious and slow 1â3. Here we report that the wild, diploid non-tuber-bearing Solanum americanum harbors multiple Rpi genes. We combine R gene sequence capture (RenSeq4) with single-molecule real-time SMRT sequencing (SMRT RenSeq) to clone Rpi-amr3i . This technology should enable de novo assembly of complete nucleotide-binding, leucine-rich repeat receptor (NLR) genes, their regulatory elements and complex multi-NLR loci from uncharacterized germplasm. SMRT RenSEQ can be applied to rapidly clone multiple R genes for engineering pathogen-resistant crops
Promising high-yielding tetraploid plantain-bred hybrids in west Africa
Open Access Journal; Published online: 21 April 2019The devastating threat of black leaf streak disease caused by Pseudocercospora fijiensis on plantain production in West Africa spurred the development of resistant hybrids. The goal of this research and development (R&D) undertaken was assessing the development and dissemination of two plantain hybrids PITA 3 and FHIA 21 bred in the 1980s by the International Institute of Tropical Agriculture (IITA, Nigeria) and the FundaciĂłn Hondureña de InvestigaciĂłn AgrĂcola (FHIA, Honduras), respectively. In CĂŽte dâIvoire, plantain growers selected PITA 3 and FHIA 21 based on their improved agronomic characteristics and, between 2012 and 2016, they were massively propagated and distributed to farmers in Benin, Burkina Faso, CĂŽte dâIvoire, and Togo under the West Africa Agricultural Productivity Program (WAAAP) coordinated by the West and Central Africa Council for Agricultural Research and Development (CORAF). In 2016, the Centre National de Recherche Agronomique in CĂŽte dâIvoire included the hybrids in the improved cultivar directory. This R&D activity illustrates how three decades of crossbreeding, selection, and distribution led to local acceptance. It also highlights how a CORAF-led partnership harnessed CGIAR research for development. The dissemination and acceptance of these plantain hybrids will enhance the sustainable intensification in plantain-based farming systems across the humid lowlands of West and Central Africa
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