By Pallab Ghosh
BBC science correspondent
The work will take about five years to complete
The chocolate company Mars has announced that it is to decode the genetic structure of the cacao tree.
The research project, which is to be done in collaboration with the US Department of Agriculture and IT firm IBM, aims to improve cocoa production.
Scientists hope the Chocolate Genome Project can assist breeding programmes.
Understanding the tree's DNA could make crop production more resistant to pests, diseases, and water shortages that may come from a warming climate.
Howard-Yana Shapiro, Mars' global director of plant science, said African farmers stood to benefit the most as they accounted for nearly two-thirds of world cocoa production.
The research would "ultimately improve cacao trees, yield higher quality cocoa and increase income for farmers", he told BBC News.
Dr Shapiro would not be drawn on whether the research might lead to genetically modified chocolate.
"Researchers worldwide will have access to our work, the cacao genome. What they do with it, I can't control," he explained.
It is likely to take approximately five years to sequence, assemble, annotate and analyse the cacao genome.
But information will be available before then, as it is gathered, through the Public Intellectual Property Resource for Agriculture (PIPRA)
DNA sequence information will be publicly available for no charge and no information will be patented.
Dr Jane Rodgers, of the John Innes Centre in Norwich, UK, welcomed the fact that the research results would be put in a public database.
"This kind of approach is the norm," she said. "The results of the project will underpin all research in the field and stimulate its application to the greater benefit of all."
Dr John Orchard, of the Natural Resources Institute in Kent, said that it was essential to develop hardier varieties regardless of climate change.
"The cocoa crop is particularly vulnerable to disease. Sixty percent of the Brazilian harvest was wiped out by a disease called witches recently and this kind of impact is not uncommon," he told BBC News.
The research is similar to the sequencing of the rice genome five years ago.
That project has already led to "huge strides" in the basic understanding of the food crop, according to Dr Hugh Jones of the Institute of Arable Crop Research in Harpenden in Hertfordshire.
"This study should lead to similar benefits," he said.
Project workers at IBM's TJ Watson Research Centre in New York will use their experience of computational biology to create a detailed genetic map of cacao.