LINDELL BEACH, B.C. – For farmers who grow cacao trees and for producers of fine chocolate, their enterprises stand to benefit from the recent sequencing of the cacao tree genome, according to an international team led by Clair Lanaud of CIRAD in France, with Mark Guiltinan of the Pennsylvania State University and scientists from 18 other institutions.
The team sequenced the DNA of a variety of Theobroma cacao, Criollo, which is considered to produce the finest chocolate.
Their work was recently published in Nature Genetics.
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“Fine chocolate production is estimated to be less than five percent of the world cocoa production because of low productivity and disease susceptibility,” said Guiltinan, professor of plant molecular biology. “All cacao plants suffer from plant diseases. Criollo are even more susceptible. They are an inbred plant so they are smaller, slower growing.”
Cocoa is endemic to the Amazon rainforest where it is subjected to fungal diseases. When it was imported into other producing countries, it became more susceptible to pathogens and pests. Today, cocoa is grown in Africa, Asia and Central and South America, all within 20 degrees of the equator, and 70 percent of world production comes from West Africa.
According to the World Cocoa Foundation (WCF), the main fungal diseases are black pod, witches’ broom, frosty pod rot and vascular streak dieback. In West Africa, swollen shoot virus is also common.
“When you take a plant out of its natural rainforest environment and start growing several thousand plants per hectare in an agricultural situation, you have a problem,” said Guiltinan.
“You increase the opportunity for disease epidemics. Agri-chemicals and pesticides are difficult to use on a tree crop. They are difficult to apply to the whole plant and rain can wash the pesticides off. The farmers who grow the trees can’t afford them. That is why we want to do the genetic research so that producers can use a genetic approach to breeding (for pathogen resistance).”
According to WCF, worldwide there are about five to six million cacoa farmers and the number of people who depend on cocoa for their livelihood globally is close to 50 million.
Annual global cocoa production is three million tons and the annual global market value of the crop is $5.1 billion.
The annual increase in demand for cocoa has been three percent per year for the past 100 years and Guiltinan anticipates that increase to continue with population growth.
In their report, the researchers stated that “consumers have shown an increased interest for high quality chocolate made with cocoa of good quality and for dark chocolate containing a higher percentage of cocoa while also taking into account environmental and ethical criteria for cocoa production.”
Chocolate has a rich and ancient heritage. Theobroma means food of the gods. The Mayan people, long recognized as brilliant plant breeders, domesticated the Criollo variety about 3,000 years ago in Central America and it is one of the oldest domesticated tree crops.
They created a ritual beverage made from the ground cocoa beans mixed with water, black pepper, vanilla and spices.
According to the WCF, it was a beverage used during wedding ceremonies and may be the first known link between chocolate and romance. Cocoa beans were valued as money. Ancient records show that a horse could be bought for 10 beans.
