Analysis of Genetic Diversity in Theobroma cacao with Emphasis on Witches' Broom Disease Resistance

and morphological characteristics, are Criollo, Forast- ero, and Trinitario (Cheesman, 1944). The Criollo group To facilitate the identification of Theobroma cacao L. that possess represents the first domesticated cacaos, and is com- desirable traits to meet changing production and market conditions, posed of trees with thick, white or rosy beans that yield there is a need to understand the genetic relationships among T. cacao the most flavored and finest chocolate. Criollo was origi- germplasm. In addition, new cultivars are needed to provide more broadly based resistance to devastating diseases such as witches' nally cultivated in Central America but because of its broom disease (Crinipellis perniciosa (Stahel) Singer). A subset of susceptibility to diseases is infrequently cultivated today 270 T. cacao accessions based on (i) witches' broom disease resistance (Soria, 1970). Because of higher yields and greater dis- data, (ii) genetic characterization experiments, and (iii) a random ease resistance, Forastero is currently the most widely sampling of recently acquired accessions was selected from the exten- cultivated group accounting for over 80% of the world's sive germplasm collection at the Centro de Pesquisa do Cacau (CEPEC; production of cacao. The Forastero group is further Itabuna, Bahia, Brazil) in collaboration with Fazenda Almirante, a subdivided into Lower and Upper Amazon Forastero division of M&M Mars Incorporated in Itajuipe, Bahia, Brazil. Esti- with the Upper Amazon group considered more geneti- mates of genetic distance based on random amplified polymorphic cally diverse and exhibiting superior agronomic perfor- DNA (RAPD) markers were used to evaluate the genetic diversity