Résumé
Coffea canephora, (Robusta), provides 33% of worldwide coffee production, 80% and 22% of Ugandan and Brazilian coffee production, respectively. Abiotic stress such as temperature variations or drought periods, aggravated by climate changes, are factors that affect this production. This sensitivity threatens both the steady supply of quality coffees and the livelihood of millions of people producing coffee. The natural genetic diversity of C. canephora offer a potential for detecting new genetic variants related to drought adaptation. In particular, modifications occurring in genes related to abiotic stress tolerance make these genes candidate for breeding programs in order to enhance the resilience to climate change. canephora transcription factors from the DREB subfamily (Dehydration Responsive Element Binding Protein) have been recently identified as candidate genes. Indeed, in the C. canephora Conilon group, the CcDREB1D gene showed an increased expression in response to drought in the leaves of a drought tolerant clone . 1. The objectives of this study are to identify and characterize the allelic diversity (Single Nucleotide Polymorphism, SNPs) within drought-tolerant candidate genes with a special focus on the DREB subfamily genes. These genes will be annotated on the reference genome sequence of C. canephora and on a new assembly. A targeted capture array will be designed for these entire genes, and their flanking regions. These captured regions will be sequenced in a set of wild Ugandan populations. Subsequent detection of SNPs for the whole set will be used to test correlation of these SNPs with traits related to drought tolerance. We expect to understand the adaptive strategies developed by crops in the wild in order to respond to climate change and use the genetic resources within wild populations, as a basis for transferring drought- and heat-tolerance traits. (Résumé d'auteur)