Sélection Variétale Participative De Riz (Oryza Sativa L.) De Bas-Fonds Au Sud Du Sénégal

La production du riz dans les agro écosystèmes pluviaux du Sud duSénégal pourrait être améliorée par la mise à disposition des producteurs d’unegamme variétale plus large et plus adaptée. Dans cette étude, 11 variétésaméliorées de riz en provenance d’AfricaRice ont été introduites et conduitesen évaluation participative dans la commune d’Enampor en Basse Casamancepour leur adaptabilité. Quinze producteurs des villages de Brin, Badiate etEssyl ont été invités pour évaluer la performance des différentes variétéspendant la phase de maturité. Ces variétés ont été semées suivant un dispositifen blocs complets randomisés dispersés dans les trois villages (Brin, Badiateet Essyl) où chaque site représente un bloc ou répétition. Sur le planagronomique, les résultats ont montré que les variétés WAC13-WAT21-2-1,(3,2 t/ha) FKR19 (2,9 t/ha) et IR75884-12-12-14-WAB1 (2,7 t/ha) ontprésenté des rendements similaires au témoin BG 90-2 (2,6 t/ha), largementcultivé dans la zone. La durée moyenne de 50% épiaison des variétés testéesest de 91 jours, relativement hâtives comparées à celles généralement cultivéesdans les écologies de bas-fond de la zone. Les variétés WAC13-WAT21-2-1et WAC18-WAT15-3-1 ont été les plus appréciées par les producteurs selonles critères de rendement en grain et hauteur des plantes. Les variétéssélectionnées par les producteurs ont présenté également une bonne performance agronomique et ont été parmi les plus productives. Ces variétéssélectionnées pourraient être de bonnes candidates pour une large diffusionpermettant ainsi d’augmenter le choix des variétés cultivées dans la zone.L’implication des producteurs dans les programmes de sélection variétalepourrait faciliter l’adoption de nouvelles variétés qu’ils ont sélectionnéessuivant leurs préférences. Rice production in the rainfed agro-ecosystems of Southern Senegalcould be improved by providing farmers with more diverse and adaptedvarieties. In this study, 11 improved rice varieties from AfricaRice wereintroduced and assessed for adaptability through participatory evaluation trialin the village of Enampor (Lower Casamance zone). Fifteen farmers from thevillages of Brin, Badiate and Essyl were invited to assess the performance ofthe different varieties at maturity stage. The varieties were sown following arandomized complete block design with three replications where each of thethree villages (Brin, Badiate and Essyl) represented a block/repetition. Results of the agronomical performance showed that the varieties WAC13-WAT21-2-1, (3.2 t / ha) FKR19 (2.9 t / ha) and IR75884-12-12-14-WAB1 (2, 7 t / ha)presented similar grain yields as for the check variety BG 90-2 (2.6 t / ha),widely cultivated in the targeted areas. Days to 50% heading for the differentvarieties was 91 days in average, relatively early compared to those generallycultivated in the same lowland ecologies. WAC13-WAT21-2-1 and WAC18-WAT15-3-1 were the most preferred varieties by farmers according to theirown criteria mainly related to grain yield and plant height. These selectedvarieties by farmers were also among the most performing as shown in thestatistical analysis of agro-morphological data. These varieties could be goodcandidates for wide diffusion in order to increase the list of high performingcultivated varieties in the targeted areas. Involving farmers in selection andbreeding programs could facilitate the adoption of new varieties which theyselected based on their preferences

Influence of mitochondria origin on fruit quality in a citrus cybrid.

International audienceSugar, organic acid, and carotenoid are the most important indicators of fruit taste and nutritional and organoleptic quality. These components were studied on fruit pulp of the cybrid between Willow leaf mandarin ( Citrus deliciosa Ten.) and Eureka lemon [ Citrus limon (L.) Burm.] and the two parents. The cybrid possessed nuclear and chloroplast genomes of Eureka lemon plus mitochondria from Willow leaf mandarin. The impact of new mitochondria on fruit quality was studied during the mature period. Levels of organic acids were slightly higher in the cybrid fruit pulp than in Eureka lemon. No significant difference in sugar and carotenoid content was observed between the cybrid and the lemon. Results confirm that the main genetic information for the biosynthesis of sugars, organic acids, and carotenoids is contained in the nucleus. In Citrus, cybridization can be used as a strategy to breed specific traits associated with mitochondrial genomes, such as male sterility, without affecting the main organoleptic and nutritional qualities

Phytochemical analysis and antioxidant activities of Combretum molle and Pericopsis laxiflora

In Burkina Faso as in several African countries, diabetes is becoming a very serious disease and public concern. Patients use both drugs and plants for treatment. Thus, Combretum molle and Pericopsis laxiflora have been identified as plants used in Burkina Faso for the treatment of that disease. The aim of the study was to assess phytochemical components and antioxidant activities of those plants in order to highlight why diabetes patients refer to them. The phytochemical analysis of water, ash quantification and screening were done using the standard methods; the antioxidant activities of the ethanolic extract against 2, 2-diphenyl-1- picryl-hydrazyl (DPPH), nitric oxide (NO) and hydroxyl radical were performed using colorimetric or spectrophotometric methods. The Inhibitory Concentration (IC) was determined using GraphPad Prism version 5. The results showed 6.76±0.076% and 7.52±0.015% of water contents in Combretum molle and Pericopsis laxiflora, respectively. The ash content was 3.41±0.35% for Combretum molle and 3.87±0.15% for Pericopsis laxiflora. The screening revealed the presence of tannins, phenolic compounds, flavonoids and saponins in both plant materials. However, alkaloids were found in Pericopsis laxiflora and hydrolysables tannins and heterosides cardiotonics in Combretum molle. The IC50 for the extract plant of Combretum molle was 42 μg/mL and that of the Pericopsis laxiflora was 44.15 μg/mL for DPPH radical. The antioxidant effect of the extract plant of Combretum molle was 216 μg/mL and the extract plant of Pericopsis laxiflora was 225 μg/mL on the nitric oxide radical. It was concluded that the presence of tannins, flavonoids, phenolic compounds, saponin, alkaloids and cardiotonic heterosides, explains why traditional medicine uses both plants together to treat certain diseases. However, further investigations of the pharmacological potential for diabetes treatment are needed.© 2015 International Formulae Group. All rights reserved.Keywords: Phytochemical, antioxidant activities, Combretum molle, Pericopsis laxiflora, Burkina Fas

Systemic sustainability of the french organic rice and PGI Einkorn value chains: A preliminary assessment based on network analysis

Public authorities and consumers increasingly support food value chains that are more environmentally friendly. However, these value chains are faced with technical, economic and institutional limitations, calling into question their long-term viability. Based on two case studies of alternative food chains in France, namely einkorn (Triticum monococcum) in Haute Provence and organic rice in the Camargue, we evaluated their capacity to remain both viable and environmentally, economically and socially sustainable. After assessing the traditional economic, social and environmental performance of their sustainability, we performed a network analysis to determine the survivability of the systems. The combined use of the traditional pillars of sustainability and the network analysis forms what we term the systemic sustainability. Results suggest that the einkorn value chain is characterised by a high degree of centrality represented by a producers' association, although the systemic sustainability of the chain is reduced by its dependence on a leading processor. As for the organic rice value chain, centralised power is exerted by three companies embedded in a strong network of actors characterised by diversified connections. The paper concludes by highlighting the potential interest of conducting a network analysis to better determine the sustainability of food value chains

Tropheryma whipplei in Fecal Samples from Children, Senegal

We tested fecal samples from 150 healthy children 2–10 years of age who lived in rural Senegal and found the prevalence of Tropheryma whipplei was 44%. Unique genotypes were associated with this bacterium. Our findings suggest that T. whipplei is emerging as a highly prevalent pathogen in sub-Saharan Africa