W125 Marker-assisted farmer participatory selection of cacao (Theobroma cacao L.) progress and challenges

Date: Sunday, January 15, 2012
Time: 3:40 PM
Room: Royal Palm Salons 3-4
Dapeng Zhang , Sustainable Perennial Crops Laboratory, Plant Sciences Institute, USDA/ARS, Beltsville, MD
Enrique Arevalo Gardini , Intituto de Cultivos Tropicales (ICT), Tarapoto, Peru
Kun Ji , College of Horticulture and Landscape Architecture, Southwest University, Chongqing, China
Lyndel Meinhardt , Sustainable Perennial Crops Laboratory, Plant Sciences Institute, USDA/ARS, Beltsville, CA
Cacao (Theobroma cacao L.) is an important tropical crop that provides raw materials for chocolate industries. Farmer participatory selection is highly suitable for small-scale and resources-poor farmers and is complementary to centralized breeding programs in cacao producing countries. Recent progress in the development of cacao genomic resources has allowed the use of high-throughput SNP genotyping technology to backstop participatory selection. The applications included accurate genotype identification and elimination of redundancy among farmer selections, understanding on-farm genetic diversity, assessment of general combinability of parental clones through inference of parentage and sib-ship and rational deployment of new selections in rehabilitation programs. Our recent case studies showed that single nucleotide polymorphism (SNP) is a highly promising tool for marker-assisted participatory selection due to its efficiency and cost. However linking key agronomic traits in farmer selections with a small core set of SNP markers remains the main challenge.  Moreover, the large genotype x environment interaction and low heritability traits which are difficult for farmer to observe, such as tolerance to abiotic stress and flavor, call for the development of resources in cacao phenomics.