Cross-section of a
healthy cacao pod. Click the image for more information about
Cacao Symposium Tackles Chocolate Production
Problems By Alfredo Flores February 9, 2006
Agricultural Research Service (ARS) scientists have located genetic markers
for resistance to a major disease of cacao trees, the source of seeds for cocoa
The scientists found the markers for resistance to witches
broom, a disease caused by the fungus Moniliophthora perniciosa,
the main killer of Theobroma cacao trees. They are presenting this
and other research findings during a biennial
Symposium on Cocoa hosted by the
National Academy of
Sciences on February 9-10 in Washington, D.C.
Witches' broom penetrates cacao stem and fruit tissue, inhibits
formation of seed pods and destroys mature pods. Two other major
cacao-production problems being addressed by ARS researchers are frosty pod and
black pod rot.
The symposium, titled "Theobroma cacao: The Tree of Change," features
presentations on cocoa- related aspects of plant and biomedical science,
sustainable agriculture, nutrition, medicine and anthropology, along with
round-table discussions on problems and issues facing cocoa-growing regions of
West Africa, East Asia and the Americas.
Schnell will describe recent progress in the ongoing cacao breeding
program. Schnell works at ARS' Subtropical Horticulture Research Station (SHRS) in Miami,
Fla., where he and colleagues are unraveling the genome of T. cacao.
Traditional cacao breeding programs have been only marginally
successful in producing disease- resistant material that also shows suitable
commercial characteristics. Since 1999, the SHRS, in collaboration with
Mars Inc., of Hackettstown, N.J., have been
studying ways to speed up cacao breeding while reducing costs.
Already, scientists have succeeded in genetically mapping T.
cacao species, segregating them according to resistance, and identifying
genes that influence resistance and productivity. Thus, the use of new genomic
technologies will help ensure sufficient cocoa to meet world demands.
ARS Deputy Administrator
Collins, director of the
Plant Sciences Institute; and
Meinhardt, research leader of the ARS
Perennial Crops Laboratory, Beltsville, Md., are co-chairing symposium
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.