科学家揭开巧克力的基因密码

Chocolate lovers around the world take note: two separate groups of scientists have unraveled the genetic code of your favorite sweet.It's good news for the millions of small farmers in Africa, Asia and Latin America whose livelihoods depend on the seeds of the cacao tree.

Candy is serious business. The world's top-10 confectioners sold more than $40 billion of it in 2005.

But many of the more than five million farmers worldwide who produce cocoa, the main ingredient in chocolate, are living in poverty.

Yield gap

One reason for that is that their farms are not very productive, according to Howard-Yana Shapiro, head of plant research for the US-based candy giant, Mars Inc. Shapiro says the average West African cacao tree farmer produces only about 400 kilograms of cocoa beans per hectare.

 

"There's a yield potential of maybe 4,000 kilos, 10 times what the average is in West Africa," he says. "We saw the disparity."

To reduce that disparity, Mars helped fund a project to sequence the genome of the cacao tree. The Mars project sequenced the most common variety. French researchers led a separate effort focusing on the high-quality Criollo variety.

Cocoa disease

Genome data is expected to help with some of the most common problems facing cacao growers. Each year farmers lose about a third of their harvest to pests and fungal diseases, says Bill Guyton, president of the World Cocoa Foundation, an industry-sponsored group promoting sustainable cocoa farming.

"This type of program we feel is going to be very beneficial in helping to breed trees that are more tolerant or resistant against some of the fungal pests," he says. And with better productivity, he adds, farmers can earn more money and improve their social conditions.

 

Mars team leader Shapiro says it's a win-win both for the company and for cocoa farmers.

"We want to be in business sustainably in the future. We want to have certified cocoa that is sustainably grown. We want the farmers to have a sustainable life. We don't want them to all have to move to the city."

The genome data will be publically available without restrictions or patents. Shapiro expects improved cacao trees to start reaching farmers in about three years.