The Generation Challenge Programme aims at making the most of sources of genetic diversity maintained in world collections and breeding programs to identify and use genes and superior alleles for key agricultural traits, especially drought tolerance. In sorghum, a composite collection of about 3400 accessions has been characterized with 42 microsatellites through a collaborative effort associating ICRISAT, Agropolis-CIRAD and CAAS. The resulting dataset provide a basis for the exploration of genetic diversity at different scales. High throughput marker systems such as DArT are being used for whole genome profiling and reveal their efficiency in linkage disequilibrium analysis and for further whole genome association scans. This presentation also emphasizes results on analysis of allelic diversity of known genes and its comparison with pangenomic diversity which gives different pictures of the structure of sorghum genetic diversity. (Texte intégral)