AbstractThe expression of monogenic and polygenic characters has been studied in families of spontaneous haploids of cocoa which nave been doubled with colchicine. Segregation of six enzyme markers, heterozygous in the various parent clones, has been analysed in the doubled haploids for alcohol dehydrogsnase (ADH), malate dehydrogenase locus B (MDH‐B), isocitrate dehydrogenase (IDH), acid phosphatase (ACP), phosphoglucomutase (PGM) and phosphoglucose isomerase (PGI). Nine of the eleven families showed a Mendelian‐type segregation, two presented distortions but all alleles were found in the haploid progenies.Polygenic characters were expressed with great variability: A few DHs showed similar or even higher values than their parents for individual characters, but the majority were lower, and large depressions could be seen for the group of characters studied.These results have consequences for the use of doubled haploids of cocoa which must both give a sure production of hybrid seeds and be good progenitors; no prediction of their value as progenitors seems possible after observation of their own characteristics and the only selection made from these plants will bea propostheir characters directly involved in seed production. These selected doubled haploids will subsequently have to be tested as progenit
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