Hydro-political assessment of water governance from the top-down and review of literature on local level institutions and practices in the Volta Basin

Water resource management / Governance / River basin development / Water law / Colonialism / Institutions / Social participation / Women / Water use

Cocoa introductions into Ghana

Cocoa breeding and selection programmes in Ghana and other West African countries have been based largely on existing cultivated populations or on few collections of wild cocoa. The most widely used cocoa germplasm derives from the material collected by F. J. Pound during the periods 1937-1938 and 1942-1943 and distributed as the Iquitos Mixed Calabacillos (IMC), Nanay, Parinari, Scavina, and the Pound series of clones. This material collected in the Upper Amazon region has been particularly successful, suggesting that cacao would be greatly improved if more germplasm material were provided for use by breeders. Maintaining adequate genetic variability in cocoa germplasm collection, essential for sustainable cocoa production, can be realised through active and conscious germplasm acquisition. Because there is the risk of accidentally introducing diseases and pests along with cocoa germplasm material, effective indexing procedures, together with the availability of final quarantine houses in individual producing countries, are essential to ensure that introduced materials are free of diseases and pests. To be successful as breeding material for producing improved varieties for farmers, the introductions must have some desirable characteristics acceptable to chocolate manufacturers and farmers.Les programmes de reproduction et de sélection de cacao au Ghana et dans d'autres pays de l'Afrique occidentale ont été fondé en grande partie sur les populations de cultures existantes oú sur un tous petit nombre de collections de cacao sauvage. Le germeplasme de cacao le plus utilisé sur une grande étendue vient de matières ramassées par F. J. Pound en 1937-1938 et en 1942-1943 et distribuées sous les noms d'Iquitos Mixed Calabacillos (IMC), Nanay, Parinari, Scavina et Pound comme des séries de clones. Une succès particulier a été réalisé avec cette matière ramassée de la région de Haute Amazone. Ce succès suggère que même de plus grandes améliorations en cacao pourraient être possible si beaucoup auraient été disponible pour utilisation par les phytogéticiens. Le maintien de variabilité génétique adéquate en collection de germeplasme de cacao est essentiel pour la production durable de cacao et ceci pourrait être réalisé par acquisition active et consciente de germeplasme. Puisqu'il y a le risque d'introduire par hasard les maladies et les insectes nuisibles avec la matière de germeplasme du cacao, les procédures efficaces d'indexation, ainsi que la disponibilité de salles de quarantaine finale dans chaque pay producteur sont essentiel pour assurer que les matietes introduietes sont sans maladies et insectes nuisibles. Pour réussir comme matière de reproduction pour la production de variétés améliorés pour les agriculteurs, les introductions devraient avoir quelques caractéristiques désirables er acceptables aux fabriquants de chocolat et aux agriculteurs. Ghana Journal of Agricultural Science Vol. 39 (2) 2006: pp. 22

Applying SNP marker technology in the cacao breeding programme in Ghana

In this investigation 45 parental cacao plants and five progeny derived from the parental stock studied were genotyped using six SNP markers to determine off-types or mislabeled clones and to authenticate crosses made in the Cocoa Research Institute of Ghana (CRIG) breeding programme. Investigation was based on the 5\u2019 nuclease SNPassay using Illustra Hot Start mix Ready-To-Go PCR strips and BioTek FLx800TBP Fluorescence Microplate Reader. In a group of six cacao plants labeled as PA150 clones and another five labeled as Pound7, one clone in each group was unambiguously determined as off-type or mislabeled. Similarly, in a cohort of 23 PA7 "clones", four genotypes were differentiated. Cross-checking the fidelity of five progeny from the parental stock under study, it was established that no errors were made in the crossing. The most significant outcome of this study, however, was that out of the four categories of 23 PA7 candidate parental trees only one category can be comparable to the reference clone in the International Cacao Germplasm collection, Trinidad (ICG,T); thus informing the need for further work to find the correct clone among these for the breeding programme. It was thus concluded that thissimple yet cutting-edge genotyping procedure can be used in applied cocoa breeding programmes in a cocoa producing country. This work represents a first step in the genotypic characterisation of the CRIG germplasm collection and Seed Gardens.Au cours de cette recherche, 45 plants de cacao parentaux et 5 descendants d\ue9rivant du stock parental ont \ue9t\ue9 g\ue9notyp\ue9 en utilisant 6 marqueurs SNP, afin de d\ue9terminer les clones mal \ue9tiquet\ue9s et d\u2019authentifier les croisements effectu\ue9s dans le programme d\u2019am\ue9lioration de l\u2019Institut de Recherche sur le Cacao au Ghana (CRIG). Cette \ue9tude a \ue9t\ue9 bas\ue9e sur les 5' nucl\ue9ases SNP en utilisant des bandes PCR "Hot Start mix Ready-To-Go PCR strips" et un Lecteur Microplat \ue0 Fluorescence "BioTek FLx800TBP". Au sein d\u2019un groupe de six plants de cacao \ue9tiquet\ue9 PA150 et d\u2019un autre groupe de cinq \ue9tiquet\ue9 Pound 7, il a \ue9t\ue9 d\ue9termin\ue9 sans ambigu\ueft\ue9 qu\u2019un clone par groupe \ue9tait mal \ue9tiquet\ue9. De fa\ue7on similaire, quatre g\ue9notypes diff\ue9rents ont \ue9t\ue9 identifi\ue9s dans une m\ueame cohorte de clones 23PA7. En v\ue9rifiant la fid\ue9lit\ue9 de cinq descendants issus du stock parental \ue9tudi\ue9, il a \ue9t\ue9 \ue9tabli qu\u2019aucune erreur n\u2019avait \ue9t\ue9 faite lors du croisement. Le r\ue9sultat le plus significatif de cette \ue9tude a \ue9t\ue9 que, sur quatre cat\ue9gories de 23 candidats PA7 de souches parentales, une seule pouvait \ueatre comparable au clone de r\ue9f\ue9rence dans la collection Internationale du Germoplasme de Cacao, Trinidad (ICG,T), d\ue9montrant ainsi la n\ue9cessit\ue9 de travaux suppl\ue9mentaires pour d\ue9terminer le clone exact parmi ceux \ue9voqu\ue9s pr\ue9c\ue9demment. Il a ainsi \ue9t\ue9 conclu que cette m\ue9thode avant-gardiste de g\ue9notypage, pourtantsimple, peut \ueatre utilis\ue9e dans les programmes appliqu\ue9s d\u2019am\ue9lioration du cacao dans un pays producteur. Ce travail repr\ue9sente une premi\ue8re \ue9tape dans la caract\ue9risation g\ue9n\ue9tique de la collection du germoplasme CRIG et jardins semenciers

α2-Macroglobulin can crosslink multiple plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) molecules and may facilitate adhesion of parasitized erythrocytes

Rosetting, the adhesion of Plasmodium falciparum-infected erythrocytes to uninfected erythrocytes, involves clonal variants of the parasite protein P. falciparum erythrocyte membrane protein 1 (PfEMP1) and soluble serum factors. While rosetting is a well-known phenotypic marker of parasites associated with severe malaria, the reason for this association remains unclear, as do the molecular details of the interaction between the infected erythrocyte (IE) and the adhering erythrocytes. Here, we identify for the first time a single serum factor, the abundant serum protease inhibitor α2-macroglobulin (α2M), which is both required and sufficient for rosetting mediated by the PfEMP1 protein HB3VAR06 and some other rosette-mediating PfEMP1 proteins. We map the α2M binding site to the C terminal end of HB3VAR06, and demonstrate that α2M can bind at least four HB3VAR06 proteins, plausibly augmenting their combined avidity for host receptors. IgM has previously been identified as a rosette-facilitating soluble factor that acts in a similar way, but it cannot induce rosetting on its own. This is in contrast to α2M and probably due to the more limited cross-linking potential of IgM. Nevertheless, we show that IgM works synergistically with α2M and markedly lowers the concentration of α2M required for rosetting. Finally, HB3VAR06+ IEs share the capacity to bind α2M with subsets of genotypically distinct P. falciparum isolates forming rosettes in vitro and of patient parasite isolates ex vivo. Together, our results are evidence that P. falciparum parasites exploit α2M (and IgM) to expand the repertoire of host receptors available for PfEMP1-mediated IE adhesion, such as the erythrocyte carbohydrate moieties that lead to formation of rosettes. It is likely that this mechanism also affects IE adhesion to receptors on vascular endothelium. The study opens opportunities for broad-ranging immunological interventions targeting the α2M--(and IgM-) binding domains of PfEMP1, which would be independent of the host receptor specificity of clinically important PfEMP1 antigens