12 ref. Sum. (En)

In cocoa, a long time is needed for the plant to reach maturity when the most important traits can be determined. This fact is the main limitation to rapid genetic improvement in this crop. The use of molecular markers opens new possibilities for a faster selection of resistant genotypes, and the opportunity for characterising the genotypes more precisely. The present work utilised a backcross segregating population of 131 trees, for which a genetic linkage map had been previously constructed using RFLP and RAPD markers, to determine quantitative trait loci (QTL) for P. palmivora resistance. Resistance was assessed using the paper disc-humid chamber method. Statistical evaluation of resistance data with molecular marker data allowed identification of five loci associated with P. palmivora resistance on five of the ten different cacao linkage groups (chromosomes). The percent of total variance explained for each trait studied was close than 40 percent of the total variance. It shows the possibility of exploitation of this information in breeding programs.