Genetics researcher discusses defense of chocolate supply

During a San Diego genetics conference in January, a U.S. Department of Agriculture Advanced Research Station scientist gave a presentation on the protection of the world’s chocolate supply.

Raymond Schnell of the USDA-ARS Subtropical Horticultural Research Station in Miami, Florida, spoke on “Integrating Genomics into an Applied Cacao Breeding Program” during the Fruit and Nut Crops Workshop session of the January 13-17 International Conference on the Status of Plant and Animal Genome Research.

The cacao tree can be cultivated in a sustainable agro-forestry system. Four main genetic groups of cacao are traditionally classified as Criollo, Trinitario, Lower Amazon Forastero, and Upper Amazon Forastero.

Production of cacao in tropical America has been severely affected by two fungal pathogens: witches’ broom and frosty pod. “In both cases they ruin the bean,” Schnell said.

Those two diseases, along with the fungal disease black pod, were responsible for losses exceeding $700 million (in U.S. dollar equivalent) in 2001.

Witches’ broom and frosty pod are currently confined to tropical America, but commercial populations in West Africa and South Asia are highly susceptible to both diseases. “If these diseases get turned loose in West Africa or South Asia, it’s going to cause a real problem. It’s already causing a problem in Central and South America,” Schnell said.

Witches’ broom wasn’t found in Brazil until about 1987. Before the infestation, Brazil was the second-largest producer of cacao beans in the world. “Now it’s maybe tenth or eleventh because of one little fungal disease,” said Dr. Howard Shapiro, the global director of plant science and external research for Mars, Inc. “Witches’ broom took out Brazil.”

Prior to the infestation Brazil was the third-largest exporter of cacao beans in the world. Within ten years Brazil was a net importer of cacao. Between $20 million and $40 million was spent on disease control efforts. “It still came in the back door and heavily devastated a regional industry,” Shapiro said.

Traditional cacao breeding programs have been marginally successful in producing resistant material with suitable commercial characteristics. In 1999 the USDA-ARS in collaboration with Mars, Inc., initiated a project to apply modern molecular genetic techniques to cacao breeding. The objective was to develop an international marker assisted selection breeding program focusing on disease resistance. “Mainly we want to incorporate resistance into current commercial populations,” Schnell said.

The program actually began in 1998. “This was really as an alternative for narcotics crops in Central and South America,” Schnell said.

Mars, Inc., and USDA-ARS signed a five-year cooperative research and development agreement (CRADA) the following year. “Mars had been very involved in Brazil and they witnessed what had happened when the disease got brought into Brazil,” Schnell said. “We decided that we would set up a cacao sustainability program around the globe beginning with genetics,” Shapiro said. “Cacao had not been improved in a modern way for 50 or 100 years.”

While some small cross-breeding improvements to crop yield have been made by the French and Dutch, the progress doesn’t compare to that of corn, citrus, or almond yield. “There’s been a declination of improvement of yield in cacao,” Shapiro said.

Mars and USDA are now in their second five-year agreement. “We’re using the modern molecular technologies to try to speed up the breeding process,” Schnell said.

Large evaluation trials are taking place in Costa Rica, Ecuador, Brazil, and Papua New Guinea with additional studies in Ghana, Nigeria, Costa Rica, and Ecuador. The projects are all in collaboration with national agricultural institutes in the respective countries, and the international project is expected to produce new disease-resistant cultivars by 2012.

Evaluation of cultivation without the molecular aids would likely require 15 to 20 years to produce cacao with the desired traits. “You can use these new molecular technologies to speed it up,” Schnell said. “You can target the genes you’re interested in.”

The microsatellite markers allow for the production of linkage maps. “It speeds the process up, makes it a lot more efficient,” Schnell said.

“If you magnify what you see, it allows you to make selections quicker,” Shapiro said.

“It will still be a long time before it gets out in the farmer’s field,” Schnell said. “We’re hoping not as long as it has been.”

The CRADA specifies working with regional partners in Africa, Asia, Central America, and South America to understand regional needs. “In every one of those regions the issue of disease resistance and yield has become a major issue,” Shapiro said.

Approximately 98 percent of the world’s chocolate production is within 18 degrees latitude of the Equator.

The agreement allowed USDA to select a scientist, paid for by Mars, to be the lead breeder. The program also considers agro-forestry, agro-ecology, and agro-economics. “What works in Ghana doesn’t work in Ecuador,” Shapiro said. “Every place you work there is a very specific hierarchy of needs.”

Members of local scientific, forestry, and agricultural communities are more aware of those needs. “You can’t just do it as an outsider,” Shapiro said. “You have to set up collaborations with appropriate institutions.”

A field training school allows for feedback from farmers’ experiences. “We talk to all the farmers we can,” Shapiro said.

Part of the plan includes building the knowledge resources of the country. “This is not randomness. This is a long-term program where we loan people to projects to get them going,” Shapiro said. “Our goal is to replace ourselves. You want in-country experience.”

Shapiro notes that the research paid for by Mars, Inc., will also benefit other chocolate companies. “That’s okay,” Shapiro said.

“We go there because we believe it’s the responsibility of a corporation to do those things,” Shapiro said. “This is basically our view of how a corporation is supposed to work.”

Mars, Inc., is a privately-held corporation and does not face demands for dividends. It was founded in 1911 and originally produced hand-made chocolate. Its first product, Milky Way, was first sold in 1923. Mars, Inc., also produces M&M’s, Snickers, Three Musketeers, Twix, and Dove Chocolate. A separate food division produces the Uncle Ben’s rice brand, and the corporation’s pet food division sells Whiskas, Pedigree, and Sheba.

The CRADA work is not proprietary. “The work we do with them is put in the public domain so everyone has access to it equally,” Shapiro said. “Everyone should have it. This is work that affects so many people.”

Shapiro noted that farmers as well as companies will benefit from the research. “We can’t work everywhere equally, but if you improve the ones that are of the largest scale it improves the ones of the smaller scale,” he said.

The model includes crop diversity rather than growing solely cacao. “The worst thing possible is if something hits a region and all those people suffer the same plant disease simultaneously,” Shapiro said.

That portfolio also allows for revenue over an entire 12-month period rather than a five-month period.

The environmental stewardship component of the program produces additional benefits. “We know that cacao’s grown in some of the most fragile ecological landscapes,” Shapiro said. “It’s a win as well for those landscapes.”

The project also includes incorporating soil and water needs for each area. “All of these pieces have to fit together, and we work on all of them simultaneously,” Shapiro said.

“I think it’s been an incredibly fun project for me. I’ve enjoyed it very much,” Schnell said.