Cocoa is a fruit tree that has particular economic importance for the humid tropical countries where it is cultivated. After fermentation, drying and roasting, the beans are used to make chocolate. Cocoa is often cultivated under a forest canopy and in small plantations, which also means that it helps maintain biodiversity and respect the environment.

Cocoa is the first long-generation tropical fruit tree to have been sequenced. Access to its sequence now opens up a wide field of studies, allowing the genes responsible for its natural genetic variation to be characterized more quickly, not only for T. cacao adaptation to environmental conditions and disease resistance, but also for the aromatic qualities of chocolate.
Access to these genes will make it possible to find out how their expression varies within the genetic resources or under the effect of environmental factors.

This will facilitate the creation of productive disease-resistant varieties, with high quality cocoa, which will contribute to the development of sustainable cocoa production by reducing the amount of pesticide use.

Genome sequencing

The genome that was sequenced comes from the cocoa variety Criollo collected in Belize. It could be a descendent of the first cocoa trees domesticated by the Mayas over 2000 years ago. The chocolate derived from this variety is of the highest quality, classified as one of the fine flavour chocolates. The first results from these analyses will help further understanding of the genes that may be involved in the aromatic traits of chocolate or in cocoa’s disease resistance mechanisms. They also make it possible to retrace the cocoa tree’s evolutionary history.

This research will drastically increase our understanding of the cocoa tree and its improvement. This will benefit small-scale producers in developing countries, making it possible to create new productive and disease-resistant varieties more effectively, at the same time as maintaining the excellent aromatic qualities of their chocolate.

The detailed results will be published in the online edition of the review Nature Genetics on 26 December 2010.

Links between South Green and Cacao

The South Green Bioinformatics platform supported the analyses of the Cacao genome sequence.