Construction of a molecular linkage map in coffee

A linkage map for coffee (Coffea canephora P.) totalling 1402 cM has been developed on the basis of a population of doubled haploids. Both RFLP markers and PCR-based markers (RAPD) were used to construct 15 linkage groups. Coffee genomic and cDNA clones provided the source of the probes. In total, 47 RFLP and 100 RAPD loci have been placed on the linkage map. A rather low DNA polymorphism rate (18% for RFLP markers and 29% for RAPD primers) was detected. Only 81% of RAPD markers and 85% of RFLP markers fit an expected 1∶1 ratio (P<0.01). The availability of a molecular linkage map has many implications for the future development of the genetics and breeding of this commercially important crop species.