Régénération assistée du karité (Vitellaria paradoxa C. F. Gaertn.) dans les parcs agroforestiers au Burkina Faso

Le karité (Vitellaria paradoxa C. F. Gaertn.) présente une importance sociale, culturelle, économique et alimentaire pour le Burkina Faso où il occupe la quatrième place dans les produits d’exportation. La pérennité de cette espèce dont les populations rurales sont tributaires, est compromise par de multiples phénomènes dont le manque de régénération, les pratiques culturales et la coupe abusive du bois pour satisfaire les besoins énergétiques. L’objectif de cette étude est de proposer des méthodes adéquates pour rajeunir les parcs à karité au Burkina Faso. Cinq sites de recherche ont été choisis suivant un gradient phytogéographique : Sobaka, Noumoudara et Kakoumana (secteur sud soudanien), Gonsé (secteur nord soudanien) et Bouria (secteur sub sahélien). Les essais effectués dans chaque parcelle choisie, ont comporté trois répétitions et 7 traitements, représentés par les différentes techniques de régénération (plantation, transplantation, semis direct libre, semis dans les buissons, régénération naturelle assistéeRNA-, induction de drageon, induction de pousse adventive). Les résultats indiquent que le taux de survie de la régénération naturelle assistée est audessus de 70% après deux années de suivi. Les plantations et les semis directs dans les buissons sont aussi des techniques efficaces pour la régénération/restauration des parcs à karité, avec respectivement des taux de survie de 13,33% et 6,67% dans le secteur sub sahélien, 12,22% et 6% dans le nord soudanien, et 55,56% et 25,33% dans le sud soudanien après la troisième année de suivi. En conclusion, la régénération assistée est la technique la plus efficiente pour restaurer les parcs à karité. The Shea (Vitellaria paradoxa C. F. Gaertn.) is of enormous social, cultural, economic and nutritional importance for Burkina Faso where it ranks fourth in exports. The sustainability of this species on which rural populations depend is compromised by multiple phenomena, including the lack of regeneration of shea tree and the abusive cutting of wood to meet energy needs. This work aimed to propose adequate methods for rejuvenating shea parkland in Burkina Faso. Five sites distributed along a phytogeographic gradient were selected for tests : Sobaka, Noumoudara and Kakoumana (South-Sudanian phytogeographic zone), Gonsé (NorthSudanian phytogeographic zone) and Bouria (sub-Sahelian phytogeographic zone). The field trials included three repetitions by regeneration technique (planting, transplanting, direct sowing free, sowing in bushes and assisted natural regeneration -ANR-, sucker induction, induction of adventitious growth). The results indicate that the survival rate of assisted natural regeneration is above 70% after two years of follow-up. Planting and direct seeding in bushes are also effective techniques for the regeneration / restoration of shea tree parks with respectively survival rates of 13.33% and 6.67% in the sub sahelian sector, 12.22% and 6% in north sudanian, and 55.56% and 25.33% in south sudanian, after the third year of monitoring. In conclusion, in order to restore the shea parks, all seedlings regardless of their origins, will need to be assisted i

Etude des conditions de regeneration de trois Pinacees (Pinus halepensis Mill., Pinus pinaster Aiton subsp. pinaster et Pinus pinea L.) en milieu dunaire littoral

SIGLEINIST T 71312 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

A systemic approach to evaluate shea parklands as possible climate smart agriculture to be intensified in Sudanese Africa : the multidisciplinary RAMSES Project

International audienceWe have set up a project on the « Roles of shea parklands in Reduction of vulnerability of AgrosysteMs and SociEties in Sub-Saharian Africa » (RAMSES) that has been submitted to several potential funders. This project ambitions to evaluate possible regeneration, extension and ecological intensification of shea production in Sudanese Africa, which is the only area supplying the international market with shea nuts (chocolate industriy) and butter (cosmestic industry). By this agroforestry practices, sub-Saharan societies seem to respond spontaneously to the MEA, diversifying their production while minimizing environmental degradation and deforestation impacts linked to extension of the cultivated areas. However, ecosystem services provided by shea trees are neither known nor quantified. Interactions between shea parklands and their associated socioeconomic systems is also currently in tension between the increasing demand at the international level and local degradations of shea stands with increasingly limited regeneration. This results in a worrying decrease in shea production capacity while enhancing competition between farmers, between genders (shea producers are women, trees and plots belong to men), or between private buyers on which the project propose a diagnosis. The project is based on multi-disciplinary investigations in two countries that are representative of the diversity of biophysical and socio-economic situations of the shea parklands, Benin and Burkina Faso. It ambitions to provide 1) a classification, with a geographic mapping support, of ecological combined to socio-economic conditions in which parklands are still viable from a past half- century diachronic and spatial analysis of their trajectory drivers; 2) under conditions where viability is proven, an assessment of increasing trees density impacts (i) on ecosystem services (ii) on the farms income, by using quantification of the processes underlying services provided by trees, and a bio-economic model to simulate different trees density

Une diversité d’états, pratiques et liens au parc arboré soudanien (Burkina Faso)

International audienc

Mise en évidence d’une androdioécie morphologique et d’une « hétérostigmatie » chez

Introduction. Sclerocarya birrea (Anacardiaceae) est une espèce dont les fruits font l’objet d’un important commerce au Sahel. Son amélioration à travers les programmes d’hybridation est entravée par l’absence d’informations sur sa stratégie de reproduction. Nos travaux ont étudié l’anatomie florale de l’espèce au sein d’un essai de quatre provenances ouest-africaines mis en place dans la forêt de Gonsé (Burkina Faso). Matériel et méthode. L’échantillonnage a porté sur 100 fleurs de chaque provenance. Nous avons observé la morphologie des fleurs mâles et des fleurs hermaphrodites à la loupe binoculaire, compté les différentes formes du pistil en fonction des diverses provenances et étudié, par coloration à la fushine, la viabilité in vitro des grains de pollen issus d’individus mâles et d’individus hermaphrodites. Résultats. Les populations sahéliennes de Sclerocarya birrea se sont révélées androdioïques. Les fleurs hermaphrodites montrent un ovaire volumineux surmonté de un, deux ou trois stigmates distincts à style court. Leurs grains de pollen sont viables in vitro et ils ont les mêmes caractéristiques morphologiques que ceux des fleurs mâles. Discussion et conclusion. L’androdioécie morphologique mise en évidence pourrait avoir une fonction adaptative en palliant l’insuffisance de pollinisation. Elle pourrait être exploitée pour des programmes d’hybridation et pour la conception des plans d’aménagement

Synthesis and in vitro antitumor activity of ring C and D-substituted phenanthrolin-7-one derivatives, analogues of the marine pyridoacridine alkaloids ascididemin and meridine.

A series of cycle C and D-substituted phenanthrolin-7-ones, analogues of the marine pyridoacridines meridine and ascididemin have been synthesized on the basis of Diels-Alder reactions involving quinoline-5,8-dione and 2- (or un)-substituted-N,N-dimethylhydrazones. All the compounds were evaluated for in vitro cytotoxic activity against 12 distinct human cancer cell lines. They all exhibit cytotoxic activity with IC(50) values at least of micromolar order.Journal Articleinfo:eu-repo/semantics/publishe

Viability and Functionality of Bovine Chromaffin Cells Encapsulated Into Alginate-PLL Microcapsules With a Liquefied Inner Core

Implantation of adrenal medullary bovine chromaffin cells (BCC), which synthesize and secrete a combination of pain-reducing neuroactive compounds including catecholamines and opioid peptides, has been proposed for the treatment of intractable cancer pain. Macro- or microencapsulation of such cells within semipermeable membranes is expected to protect the transplant from the host’s immune system. In the present study, we report the viability and functionality of BCC encapsulated into microcapsules of alginate-poly-Llysine (PLL) with a liquefied inner core. The experiment was carried out during 44 days. Empty microcapsules were characterized in terms of morphology, permeability, and mechanical resistance. At the same time, the viability and functionality of both encapsulated and nonencapsulated BCC were evaluated in vitro. We obtained viable BCC with excellent functionality: immunocytochemical analysis revealed robust survival of chromaffin cells 30 days after isolation and microencapsulation. HPLC assay showed that encapsulated BCC released catecholamines basally during the time course study. Taken together, these results demonstrate that viable BCC can be successfully encapsulated into alginate-PLL microcapsules with a liquefied inner core

Ecosystem contributions of Sudanian agroforestry parklands in their diversity. Scientific views vs. perceptions of local societies

International audienceThe parkland is a widespread rural agroforestry landscape in dry Sudanian Africa. The woody stratum produces goods and delivers ecosystem services that are essential for the well-being and resilience of rural populations. It also generates disservices that influence the density and composition of parkland in case of mechanised farming. Moreover, fallow land, where some species regenerate, is becoming scarcer, and soils fertility decreases. The result is a trend towards specialisation, ageing and thinning tree density. Before considering support for regeneration, the diversity of local situations requires a nuanced and contextualised analysis of the park's states and contributions, and listening to the viewpoints of the stakeholders. Within the framework of the Leapagri Ramses2 program, a participatory diagnosis of ecosystem services was carried out along a 50km regional transect of Koumbia-Dano (Burkina Faso), following mappings, an agroforestry inventory (264 plots of 0.8ha) and an in situ survey of the families of 67 inventoried fields. As a result, the classic tree ecosystem services (shade, biodiversity, carbon sequestration, infiltration, fertility, forest products) assessed from the inventory vary greatly between villages according to soils and the state of economic development. Farmers' views on the expected services (hierarchy, disservices) are complicated by divergent interests within the same household and between households, depending on the cropping systems adopted or the types of farm. There are also personal or philosophical expectations linked to traditions and social affiliations such as ethnicity, clan, religion, age class, gender and education. These studies on the diversity of parks and their complex contributions to societies complete the knowledge on specialised parks. The two scientific and endogenous perspectives also complement each other to serve as inputs to multi- stakeholder debates on engaging or not in the restoration of degraded parks