Location: Subtropical Horticulture Research
Project Number: 6038-21000-023-09-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 19, 2013
End Date: Nov 28, 2015
Validate the Cocoa Research Institute of Ghana (CRIG) germplasm collection using molecular markers and phenotypic data. Map genes segregating for Phytophthora megakarya and CSSV resistance in structured populations. Establish clone trials of selected genotypes in demonstration plots. Determine the breeding value of trees from under-utilized populations. Using the newly developed Single Nucleotide Polymorphism (SNP) chip and the completed reference cacao genome sequence, identify marker/trait associations in current field trials using phenotypic data from the previously described diseases and yield traits.
At the present time, four field trials involving 6.0 hectares of land are part of the current CRIG/USDA SCA. The application of good agricultural practices such as maintenance of shade species, pruning of cacao trees, weed and ant control, cleaning of drainage system, fertilizer applications, and replanting of dead cacao plants with new seedlings will continue in the experimental areas during the new project period. Monthly evaluations of yield and disease incidence will also be recorded on a tree-by-tree basis in some of the trials as indicated below. In addition, new QTLs for resistance to BP and CSSV diseases will be identified using traditional mapping and association genetics. Validation of the efficiency of selection using the markers and using phenotypic data from field screenings will be completed.