Chocolate genome sequenced
An international team of scientists has sequenced the genome of the cacao tree, Theobroma cacao, the source of chocolate, cocoa and cocoa butter. The research, posted online at Nature Precedings, could improve the ability of cacao tree crops to withstand drought and disease, and trigger the development of better products for consumers. The cacao tree, which is native to South American rainforests, was first domesticated by the Olmec or Mayan people in Mesoamerica some 3,000 years ago. Today, cacao trees are cultivated in all humid tropical countries. Annual global production stands at 3.7 million tonnes and 6.5 million farmers rely on the crop for their livelihoods. Over 70% of the world's crop is grown in West Africa. The cacao tree is also proving useful in environmental preservation projects. 'The cocoa tree can be cultivated under forest shade, allowing for land rehabilitation and enrichment of biodiversity, while providing income for many subsistence farmers,' the researchers explain. However, cocoa farmers often struggle to keep their precious crops free of insect pests and fungal diseases, which between them are responsible for 30% of harvest losses worldwide. In this study, the scientists decoded the genome of a cacao tree of the Criollo variety collected in the Mayan mountains. Criollo is the first variety of the cacao tree to be domesticated, and its white beans deliver what the researchers describe as a 'fine-flavoured aromatic chocolate'. Relics of the ancestral Criollo can still be found in regions inhabited by the Maya. The team identified gene families linked to cocoa flavour and disease resistance. The findings should give an important boost to efforts to produce cacao trees that are more resistant to drought and disease, and to generate higher yields and a better quality end product. 'Genome sequencing helps eliminate much of the guess-work of traditional crop cultivation,' said Howard-Yana Shapiro of chocolate manufacturer Mars, which was involved in the research. 'Cocoa is what some researchers describe as an 'orphan crop', because it has been the subject of little agricultural research compared to corn, wheat and rice. 'This effort, which will allow fast and accurate traditional breeding, is about applying the best of what science has to offer in taking an under-served crop and under-served population and giving them both the chance to flourish.' The researchers conclude: 'The large amount of information generated by this project dramatically changes the status of this tropical plant and its potential interest for the scientific community. We hope this situation will encourage greater investment in research with Theobroma cacao, the "food of the Gods" whose magic flavour has spread worldwide since the time of the Maya and Aztec civilizations, and whose continued study will benefit developing countries for which cocoa is of high economic importance.'
Countries
Brazil, Côte d’Ivoire, France, South Korea, United States, Venezuela