Cacao trees (Theobroma cacao L.) of the “Guiana” genetic group: “Tanpok 2012” survey

Abstract

The wild cacao trees (Theobroma cacao L.) of French Guiana were investigated during several survey and collecting expeditions between 1985 and 1995. The many studies made of this material showed it to be highly original. New surveys were undertaken in May 2012 in south-eastern French Guiana, in the upper reaches of the Tanpok River and some of its tributaries, in order to enrich the cacao collection preserved at the Paracou-Combi site at Sinnamary (French Guiana). One of the aims of the expedition was to determine whether the populations from the upper-Tanpok were original and different from those already represented in the collection. From the 2012 mission four populations were identified. The material collected was described (location, tree and pod morphology). Genetic diversity of the collected genotypes and various controls was studied using SSR markers. The collected trees belonged to the “Guiana” group, but did not reveal any distinctive feature within the group. The genetic diversity encountered was low (He = 0.124). The outcome of these surveys is positive, since new populations were located. In order to preserve and carry out phenotypical studies (agro-morphology) on the new material collected, a plot was planted at Paracou-Combi in January 2013.