Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Tree Genetics and Genomes 973-980 Map-based cloning Polyploid SNP Introgression Recombination Coffee 2010 fdi:010052939 ENG Tree Genetics and Genomes 1614-2942 ISI:000284421100013 6 10.1007/s11295-010-0306-x https://www.documentation.ird.fr/hor/fdi:010052939 https://www.documentation.ird.fr/intranet/publi/2010/12/010052939.pdf 6 Horizon (IRD) Resistance to coffee leaf rust is conferred by S(H)3, a major dominant gene that has been introgressed from a wild coffee species Coffea liberica (genome L) into the allotetraploid cultivated species, Coffea arabica (genome (CEa)-E-a). As the first step toward the map-based cloning of the S(H)3 gene, using a bacterial artificial chromosome (BAC) library, we describe the construction of a physical map in C. arabica spanning the resistance locus. This physical map consists in two homeologous BAC-contigs of 1,170 and 1,208 kb corresponding to the subgenomes C-a and E-a, respectively. Genetic analysis was performed using a single nucleotide polymorphism detection assay based on Sanger sequencing of amplicons. The C. liberica-derived chromosome segment that carries the S(H)3 resistance gene appeared to be introgressed on the sub-genome C-a. The position of the S(H)3 locus was delimited within an interval of 550 kb on the physical map. In addition, our results indicated a sixfold reduction in recombination frequency in the introgressed S(H)3 region compared to the orthologous region in Coffea canephora. 076 UR186