Résumé
Drought is a major abiotic stress. Many candidate genes have been proposed during the last years to explain aspects of tolerance to drought stress, for a specific crop and in a specific environment. However, the relation between gene structural polymorphism and functional diversity is seldom clear. GCP (Generation Challenge Program) has decided to initiate a project called ADOC with the objective of producing a dataset of allelic diversity at orthologous candidate genes for drought tolerance in rice, sorghum, barley, chickpea, common bean, cassava and potato. The ASR (ABA, Stress and Ripening) gene family is one of the target genes chosen in this program. Many evidences show the implication of this family in drought tolerance, notably the co-localization between ASR1 locus and a QTL directly linked to drought tolerance in maize and the increase in ASR transcript level under osmotic stress in rice. We gathered all sequences available in the databases on this gene family. We use these sequences to design consensus primers in order to amplify all genes of this family in all crops. Based on phylogenetic relationships between genes, orthologous genes will be identified. In a second step, their whole sequence polymorphism will be assessed in a DNA bank of 283 reference accessions for each crop already characterized with neutral markers. This will allow us to analyze the (ortho)allelic diversity, to study the linkage desequilibrum in the selected crops along selected genes. This reference germplasm could allow testing association between genes polymorphism and trait variability. (Texte intégral)