Gene flow between domesticated plants and their wild relatives is one of the major evolutionary processes acting to shape their structure of genetic diversity. Earlier literature, in the 1970s, reported on the interfertility and the sympatry of wild, weedy and cultivated sorghum belonging to the species Sorghum bicolor in most regions of sub-Saharan Africa. However, only a few recent surveys have addressed the geographical and ecological distribution of sorghum wild relatives and their genetic structure. These features are poorly documented, especially in western Africa, a centre of diversity for this crop. We report here on an exhaustive in situ collection of wild, weedy and cultivated sorghum assembled in Mali and in Guinea. The extent and pattern of genetic diversity were assessed with 15 SSRs within the cultivated pool (455 accessions), the wild pool (91 wild and weedy forms) and between them. F (ST) and R (ST) statistics, distance-based trees, Bayesian clustering methods, as well as isolation by distance models, were used to infer evolutionary relationships within the wild-weedy-crop complex. Firstly, our analyses highlighted a strong racial structure of genetic diversity within cultivated sorghum (F (ST) = 0.40). Secondly, clustering analyses highlighted the introgressed nature of most of the wild and weedy sorghum and grouped them into two eco-geographical groups. Such closeness between wild and crop sorghum could be the result of both sorghum's domestication history and preferential post-domestication crop-to-wild gene flow enhanced by farmers' practices. Finally, isolation by distance analyses showed strong spatial genetic structure within each pool, due to spatially limited dispersal, and suggested consequent gene flow between the wild and the crop pools, also supported by R (ST) analyses. Our findings thus revealed important features for the collection, conservation and biosafety of domesticated and wild sorghum in their centre of diversity.

No abstract

As more efforts are performed to digitize Western Saharan manuscripts, for preserving the memory they represent, the need to be able to work on these digitized materials naturally grows. Beyond cataloguing, an ontology is the basis to provide to researchers new tools for retrieving and integrating these knowledge sources. In this paper, we present an ontology describing West-Saharan manuscripts. We first precise the domain and the purposes, then we illustrate each step of the ontology's building, from experts and local resources to its alignment with well-established reference ontologies, including its automatic enrichment from existing thesaurus. This incremental process may be reused in other projects.

In this work we propose to present an application that supports the representation of manuscript documents according to an ontological approach. The implementation of this application makes it possible to annotate semantically these manuscripts according to the ontology "OMOS" [1]. The semantic annotation proposed here is an annotation based on an ontology of the "OMOS" manuscripts of generation and use of specific metadata targeted to allow new methods of access to information and to extend existing ones. The proposed annotation is based on the understanding that the named entities (the author, date 'link ... etc.) mentioned in the documents constitute an important part of their semantics. Finally, this application gives us an annotation file associated with each document.