Dussert S.,CIRAD - Agricultural Research for Development |
Guerin C.,PalmElit |
Andersson M.,Swedish University of Agricultural Sciences |
Joet T.,CIRAD - Agricultural Research for Development |
And 7 more authors.
Plant Physiology | Year: 2013
Oil palm (Elaeis guineensis) produces two oils of major economic importance, commonly referred to as palm oil and palm kernel oil, extracted from the mesocarp and the endosperm, respectively. While lauric acid predominates in endosperm oil, the major fatty acids (FAs) of mesocarp oil are palmitic and oleic acids. The oil palm embryo also stores oil, which contains a significant proportion of linoleic acid. In addition, the three tissues display high variation for oil content at maturity. To gain insight into the mechanisms that govern such differences in oil content and FA composition, tissue transcriptome and lipid composition were compared during development. The contribution of the cytosolic and plastidial glycolytic routes differed markedly between the mesocarp and seed tissues, but transcriptional patterns of genes involved in the conversion of sucrose to pyruvate were not related to variations for oil content. Accumulation of lauric acid relied on the dramatic up-regulation of a specialized acyl-acyl carrier protein thioesterase paralog and the concerted recruitment of specific isoforms of triacylglycerol assembly enzymes. Three paralogs of the WRINKLED1 (WRI1) transcription factor were identified, of which EgWRI1-1 and EgWRI1-2 were massively transcribed during oil deposition in the mesocarp and the endosperm, respectively. None of the three WRI1 paralogs were detected in the embryo. The transcription level of FA synthesis genes correlated with the amount of WRI1 transcripts and oil content. Changes in triacylglycerol content and FA composition of Nicotiana benthamiana leaves infiltrated with various combinations of WRI1 and FatB paralogs from oil palm validated functions inferred from transcriptome analysis. © 2013 American Society of Plant Biologists. All Rights Reserved.
Affokpon A.,Institute National des Recherches Agricoles du Benin |
Affokpon A.,International Institute Of Tropical Agriculture |
Affokpon A.,Catholic University of Leuven |
Coyne D.L.,International Institute Of Tropical Agriculture |
And 4 more authors.
Soil Biology and Biochemistry | Year: 2011
Seventeen isolates of the free-living soil fungus Trichoderma spp., collected from Meloidogyne spp. infested vegetable fields and infected roots in Benin, were screened for their rhizosphere competence and antagonistic potential against root-knot nematodes, Meloidogyne incognita, in greenhouse pot experiments on tomato. The five isolates expressing greatest reproductive ability and nematode suppression in pots were further assessed in a typical double-cropping system of tomato and carrot in the field in Benin. All seventeen isolates were re-isolated from both soil and roots at eight weeks after application, with no apparent crop growth penalty. In pots, a number of isolates provided significant nematode control compared with untreated controls. Field assessment demonstrated significant inhibition of nematode reproduction, suppression of root galling and an increase of tomato yield compared with the non-fungal control treatments. Trichoderma asperellum T-16 suppressed second stage juvenile (J2) densities in roots by up to 80%; Trichoderma brevicompactum T-3 suppressed egg production by as much as 86%. Tomato yields were improved by over 30% following the application of these biocontrol agents, especially T. asperellum T-16. Although no significant effects were observed on carrot galling and yield, soil J2 densities were suppressed in treated plots, by as much as 94% (T. asperellum T-12), compared with the non-fungal controls. This study provides the first information on the potential of West-African Trichoderma spp. isolates for use against root-knot nematodes in vegetable production systems. The results are highly encouraging, demonstrating their strong potential as an alternative and complementary crop protection component. © 2010 Elsevier Ltd.
Menkir A.,International Institute Of Tropical Agriculture |
Adetimirin V.O.,University of Ibadan |
Yallou C.G.,Institute National des Recherches Agricoles du Benin |
Gedil M.,International Institute Of Tropical Agriculture
Crop Science | Year: 2010
Striga hermonthica causes significant yield loss in maize (Zea mays L.) and other cereals. Lim-ited studies have been conducted to determine the relationship between marker-based genetic distance among maize inbred lines expressing varying levels of field resistance to S. hermonthica and the reaction patterns of the resulting crosses to S. hermonthica. Forty-five diallel crosses of 10 parental lines were evaluated with and without S. hermonthica infestation at two locations each in Benin Republic and Nigeria for 3 yr. Canonical discriminant analysis using nine traits separated the crosses into three distinct groups in each country depending on doses of resistance obtained from their parental lines. Hybrids formed from two resistant parents had the highest levels of resistance, while those formed from two susceptible parents exhibited the lowest levels of resistance to S. hermonthica. Crosses that involved one resistant line as a parent showed intermediate levels of field resistance to S. hermonthica. Assessment of genetic divergence among the 10 parental lines using 18 amplified fragment length polymorphism (AFLP) primer combinations generated a total of 1176 polymorphic AFLP fragments. The genetic distance (GD) estimates among all pairs of parental lines varied from 0.44 to 0.93, with an average of 0.63 ±0.023. The correlation between the AFLP-based GD estimates of parental lines and the means observed in diallel crosses under S. hermonthica infestation were not significant for grain yield and other traits. Some hybrids formed from inbred lines with GD estimates both below and above 0.50 exhibited good performance under S. hermonthica infestation. The observed broad range of genetic divergence detected with AFLP markers indicates the presence of a significant reservoir of diversity among resistant lines that can be exploited in breeding. © Crop Science Society of America.
Agbobatinkpo P.B.,University Abomey Calavi |
Agbobatinkpo P.B.,Institute National des Recherches Agricoles du Benin |
Thorsen L.,Copenhagen University |
Nielsen D.S.,Copenhagen University |
And 4 more authors.
International Journal of Food Microbiology | Year: 2013
Yanyanku and Ikpiru made by the fermentation of Malcavene bean (Hibiscus sabdariffa) are used as functional additives for Parkia biglobosa seed fermentations in Benin. A total of 355 aerobic endospore-forming bacteria (AEFB) isolated from Yanyanku and Ikpiru produced in northern and southern Benin were identified using phenotypic and genotypic methods, including GTG5-PCR, M13-PCR, 16S rRNA, gyrA and gyrB gene sequencing. Generally, the same 5-6 species of the genus Bacillus predominated: Bacillus subtilis (17-41% of isolates), Bacillus cereus (8-39%), Bacillus amyloliquefaciens (9-22%), Bacillus licheniformis (3-26%), Bacillus safensis (8-19%) and Bacillus altitudinis (0-19%). Bacillus aryabhattai, Bacillus flexus, and Bacillus circulans (0-2%), and species of the genera Lysinibacillus (0-14%), Paenibacillus (0-13%), Brevibacillus (0-4%), and Aneurinibacillus (0-3%) occurred sporadically. The diarrheal toxin encoding genes cytK-1, cytK-2, hblA, hblC, and hblD were present in 0%, 91% 15%, 34% and 35% of B. cereus isolates, respectively. 9% of them harbored the emetic toxin genetic determinant, cesB. This study is the first to identify the AEFB of Yanyanku and Ikpiru to species level and perform a safety evaluation based on toxin gene detections. We further suggest, that the gyrA gene can be used for differentiating the closely related species Bacillus pumilus and B. safensis. © 2013 Elsevier B.V.
Gaiser T.,University of Bonn |
Judex M.,University of Bonn |
Igue A.M.,Institute National des Recherches Agricoles du Benin |
Paeth H.,University of Würzburg |
Hiepe C.,Food and Agriculture Organisation
Agricultural and Forest Meteorology | Year: 2011
In this century climate change is assumed to be the major driver for changes in agricultural systems and crop productivity at the global scale. However, due to spatial differences in cropping systems and in the magnitude of climatic change regional variations of climate change impact are expected. Furthermore, the recent climate projections are highly uncertain for large parts of West Africa. In particular with respect to annual precipitation and variability the projections vary between trends with decreasing precipitation and trends with slightly increasing precipitation within the next decades. On the other hand, the extensive fallow systems in this region suffer from increasing population pressure, which compromises soil fertility restoration. In the Republic of Benin, the demographic projections for the first half of this century indicate a continuous growth of the population with a narrow interval of confidence. Thus, in the absence of an adequate soil fertility management with judicious use of mineral fertilizers, the soil degradation process with decreasing crop yields is expected to continue. The objective of this paper was, therefore, to quantify the regional effect of future population growth on crop yields in West Africa and to compare it with the potential effects of climate change scenarios. Three land use scenarios (L1, L2 and L3) for the Upper Ouémé catchment where derived from different demographic projections combined with assumptions regarding future road networks and legal frameworks for forest protection using the CLUE-S modeling approach. The fallow-cropland ratio decreased in the three scenarios from 0.87 in the year 2000 to 0.66, 0.48 and 0.68 for L1, L2 and L3, respectively in 2050. Based on the projected ratio of fallow and cropland, trends of maize yield for the three land use scenarios were calculated using the EPIC (Environmental Policy Integrated Climate) model coupled with a spatial database. Maize yields followed the decreasing trend of the fallow-cropland ratio and estimated yield reductions amounted to up to 24% in the period 2021-2050. This trend was compared with the impact of the SRES climate scenarios A1B and B1 based on the output of the GCM ECHAM5 downscaled with the REMO model and the A1B scenario output of the GCM HADC3Q0 downscaled with the RCMs SMHIRCA and HADRM3P. The yield reductions due to the projected climate change in the three models accounted for a yield decrease of up to 18% (REMO A1B scenario) in the same period. Taking into account the smaller uncertainties in the scenario assumptions and in the model output of the land use scenarios, it is concluded that, in low input fallow systems in West Africa, land use effects will be at least as important as climate effects within the next decades. © 2011 Elsevier B.V.
Yehouenou A. Pazou E.,University Abomey Calavi |
Azehoun J.P.,Institute National des Recherches Agricoles du Benin |
Aleodjrodo P.E.,University Abomey Calavi |
Van Straalen N.M.,VU University Amsterdam |
And 2 more authors.
Archives of Environmental Contamination and Toxicology | Year: 2013
To determine possible human and environmental health risks, organochlorine pesticide residues were determined in vegetables grown in floodplains along the Ouémé River near Lowé in Bénin. Testing of vegetables found 13 pesticides with ΣDDT, α-endosulfan, Σdrin, and lindane being most important. The same pesticides were also detected in plants eaten by bovine cattle, sheep, and herbivorous fish. Human pesticide intake by vegetable consumption was compared with tolerable daily intake (TDI) values reported by the World Health Organization. Pesticide intake by fish consumption was estimated from residue levels in whole fish collected from the Ouémé River in 2004 and reported earlier. Fish consumption does not pose a risk for human health, but consuming vegetables that contain pesticide residues may lead to exceedance of TDI values. Based on these findings, concerns are warranted, and more work is needed to understand the full exposure profile for the local population. © 2013 Springer Science+Business Media New York.
Sodjinou E.,Institute National des Recherches Agricoles du Benin |
Henningsen A.,Copenhagen University |
Koudande O.D.,Institute National des Recherches Agricoles du Benin
Tropical Animal Health and Production | Year: 2012
Community-based poultry health management (CBM) is a strategy for village poultry improvement based on the installment of "poultry interest groups" in experimental villages. These groups serve as a channel for the dissemination of village poultry improvement technologies. The use of CBM is due to the fact that village poultry farming is practiced in a total or partial scavenging system which gives the impression that all the birds in the village belong to the same flock. Accordingly, actions that target all farmers of the same village may have a larger impact on the village poultry's survival rate than actions that target individual producers. The objective of this study is to assess the impact of CBM on the survival rate of village poultry. Based on data collected on 353 poultry keepers, the study shows that CBM significantly improves the survival rate of village poultry. The adoption of technologies-poultry vaccination, construction of henhouses, and improved feed-disseminated through the CBM also significantly improves the survival rate. The access to markets for inputs and veterinary services is also important in improving the survival rate of poultry. Finally, the study suggests that governments and development agencies can improve village poultry survival rates by investing in the dissemination of information regarding best husbandry management practices through approaches that rely on the community such as CBM because CBM groups serve as channels for the dissemination of village poultry improvement technologies. © 2012 Springer Science+Business Media B.V.
Sodjinou E.,Institute National des Recherches Agricoles du Benin
Tropical animal health and production | Year: 2012
Community-based poultry health management (CBM) is a strategy for village poultry improvement based on the installment of "poultry interest groups" in experimental villages. These groups serve as a channel for the dissemination of village poultry improvement technologies. The use of CBM is due to the fact that village poultry farming is practiced in a total or partial scavenging system which gives the impression that all the birds in the village belong to the same flock. Accordingly, actions that target all farmers of the same village may have a larger impact on the village poultry's survival rate than actions that target individual producers. The objective of this study is to assess the impact of CBM on the survival rate of village poultry. Based on data collected on 353 poultry keepers, the study shows that CBM significantly improves the survival rate of village poultry. The adoption of technologies--poultry vaccination, construction of henhouses, and improved feed--disseminated through the CBM also significantly improves the survival rate. The access to markets for inputs and veterinary services is also important in improving the survival rate of poultry. Finally, the study suggests that governments and development agencies can improve village poultry survival rates by investing in the dissemination of information regarding best husbandry management practices through approaches that rely on the community such as CBM because CBM groups serve as channels for the dissemination of village poultry improvement technologies.
Gnankine O.,University of Ouagadougou |
Mouton L.,CNRS Biometry and Evolutionary Biology Laboratory |
Henri H.,CNRS Biometry and Evolutionary Biology Laboratory |
Terraz G.,CNRS Biometry and Evolutionary Biology Laboratory |
And 4 more authors.
Insect Conservation and Diversity | Year: 2013
1.The whitefly Bemisia tabaci is a pest of many agricultural and ornamental crops worldwide and particularly in Africa. B. tabaci is a complex of more than 20 biotypes. Effective control of B. tabaci calls for a greater knowledge of the local biological diversity in terms of biotypes or putative species. Information is available about biotype distribution in Northern, Eastern, and Southern Africa, but data for Western Africa remain very scarce. At the time of this study, data were available for only three sampling sites in Burkina Faso, where three biotypes have been detected, the native Sub-Saharan Africa non-Silver Leafing (AnSL), the Sub-Saharan Africa Silverleafing (ASL), and the Mediterranean Q biotypes, but no information is available about their respective distributions on host plant species (Gueguen, 2010). 2.Our study describes the biotypes and symbiotic bacterial communities of B. tabaci sampled in three West African countries, Burkina Faso, Benin, and Togo. A total of 527 individuals were collected from seven cultivated host plants. 3.In the 20 localities studied, we found the same three biotypes AnSL, ASL, and Q previously detected in Burkina Faso. These biotypes display a specific pattern of geographical distribution influenced by the host plant species. In Benin and Togo, the ASL and AnSL biotypes were predominant, while in Burkina Faso, the Q biotype was dominant, with two sub-groups, Q1 and Q3 (recorded to date only in this country), and ASL individuals found in sympatry with Q1 individuals in some localities. As previously reported, each biotype and each genetic group harbours a specific community of symbiotic bacteria. © 2012 The Royal Entomological Society.
HoundeTe T.A.,Institute National des Recherches Agricoles du Benin |
KeToh G.K.,University of Lomé |
Hema O.S.A.,Institute National Of Lenvironnement Et Of La Recherche Agricole |
BreVault T.,CIRAD - Agricultural Research for Development |
And 2 more authors.
Pest Management Science | Year: 2010
BACKGROUND: The tobacco whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), has developed a high degree of resistance to several chemical classes of insecticides throughout the world. To evaluate the resistance status in West Africa, eight insecticides from different chemical families were tested using the leaf-dip method on four field populations collected from cotton in Benin, Togo and Burkina Faso. RESULTS: Some field populations showed a significant loss of susceptibility to pyrethroids such as deltamethrin [resistance ratio (RR) 3-5] and bifenthrin (RR 4-36), to organophosphates (OPs) such as dimethoate (RR 8-15) and chlorpyrifos (RR 5-7) and to neonicotinoids such as acetamiprid (RR 7-8) and thiamethoxam (RR 3-7). Bemisia tabaci was also resistant to pymetrozine (RR 3-18) and to endosulfan (RR 14-30). CONCLUSION: The resistance of B. tabaci to pyrethroids and OPs is certainly due to their systematic use in cotton treatments for more than 30 years. Acetamiprid has been recently introduced for the control of whiteflies. Unfortunately, B. tabaci populations from Burkina Faso seem to be already resistant. Because cross-resistance between these compounds has never been observed elsewhere, resistance to neonicotinoids could be due to the presence of an invasive B. tabaci biotype recently detected in the region. © 2010 Society of Chemical Industry.