Cocoa Genetics and Breeding - · PDF file54 February 2011 † The Manufacturing...

54 February 2011 • The Manufacturing Confectioner

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Mankind has enjoyed the fruits of thecacao tree for more than three mil-

lennia. While early inhabitants of the Amer-icas probably did some of their own selec-tions, the notion of breeding for this cropis new. Interest in collecting and then breed-ing spread to a number of cocoa researchcenters around the world in the early 1900swhen they were formed. Breeding began inearnest in the 1940s. As we look back onthe notion of breeding for cacao, however,only modest progress has been made inmost areas of concern— disease resistanceand productivity in particular — with onlya few exceptions. Our original breedingapproaches were based on the commonlyunderstood structure of “criollo, forastero,trinitario” populations. Recent geneticapproaches have revealed a totally differentunderstanding of the underlying genome —driving a new opportunity for classical cocoabreeding in the future.

ORIGINS AND HISTORICAL SPREAD

With the release of the cocoa genomesequence into the public domain, cocoa hastaken the first steps away from its historicalorphan-crop status. Now current best-prac-tice scientific tools are applied to leverageclassical breeding of the crop. In order tounderstand the transformation that has

occurred, it is necessary to review the originsand history of the spread of the crop fromMesoamerica and South America to today’sgrowing regions of the world, and the his-tory and limitations of breeding that thecrop has faced over the decades.

The origins of this ancient crop extendback into the early paleohistory of SouthAmerica. Recent studies on the diversity ofthe genetic structure of the crop suggestthat the locus of its origin occurred some-where on the eastern side of the Andes inthe upper Amazon forests behind Peru,Ecuador, Colombia and Venezuela (Fig-ure 1). Today this is the center of the species’greatest genetic diversity and the location ofboth historical and current collecting expe-ditions to acquire additional germplasm.

Cocoa Genetics andBreedingThanks to modern genetic tools, the next two decades will witnesschanges in cocoa growing that were once only dreamed about.

Edward S. SeguineMars Chocolate North America

Edward Seguine is achocolate researchfellow at Mars Choco-late North America.From 1983 to Janu-ary 2009 he workedat Guittard Chocolateand prior to that hespent 15 years atProcter & Gamble.

Figure 1

Paleohistoric Origins of Cacao