Interspecific Hybridization Between Theobroma cacao and Theobroma grandiflorum

Theobroma cacao L. (cacao) is a perennial tree native to the Amazon and is widely known for its use in the production of chocolate and cocoa butter. Theobroma grandiflorum Schum (cupuaçu), closely related to T. cacao and also native to the Amazon, is commercially grown in Brazil for its flavorful pulp and for its butter used in the cosmetic industry. From the seeds, a mass can be obtained and converted into “cupulate”. Both species belong to the Malvaceae sensu lato and have a diploid chromosome number of 2n=2x=20. Karyological analyses of the chromosomes of both species suggest that they have been largely conserved and the pericentromeric chromatin is the only cytologically differentiated region between the two species. Interspecific hybridization does not occur naturally between cacao and cupuaçu, but has been successful under artificial pollinations. The work presented here describes the process for obtaining interspecific hybrids at the Mars Center for Cocoa Science and their characterization at the genetic, molecular and chemical levels.