Project Number: 6631-21000-017-21
Project Type: Specific Cooperative Agreement

Start Date: Oct 27, 2006
End Date: Dec 31, 2010

Objective:
Identify molecular markers linked to resistance to VSD, Phythophthora pod rot (Ppr), Longicorn (trunk borer), productivity, vigor and quality by developing appropriate families to locate these markers. A linkage map will be developed using the 500 progeny from the cross K82 x KA2-101. We will attempt to associate the molecular makers with quantitative trait loci (QTL) that should be detected for disease resistance, quality and productivity.

Approach:
The parents used in this study have been developed in Papua New Guinea (PNG) and used as parents for the SG2 hybrid developed by the Cocoa and Coconut Institute (CCI). Both clones are Trinitario. K82 has relatively low vigor and produces green pods with light reddish patches. It is resistant to black pod disease (Ppr) and Fish Bone Disorder (FBD) probably caused by Colletotrichum, but susceptible to VSD and Longicorn. KA2-101 is a more vigorous clone producing dark red pods. It is resistant to VSD and Longicorn, but susceptible to Ppr and FBD. The production of full-sibs from these parents gives the unique opportunity to study the segregation pattern of genes associated with resistance for both these diseases and will provide information on the interaction of resistance genes for different pathogens.