Cocoa black pod rot causes almost 30 % losses in world

cocoa production. This disease is caused by various species

of the genus Phytophthora. The most harmful species,

P. megakarya , is currently invading Ivory Coast, the leading

producing country. Faced with this threat, teams of researchers

from CIRAD in France, IRAD in Cameroon, CNRA in Ivory Coast

and CRU in Trinidad came together in a research project

on the genetic bases of cocoa tree resistance to Phytophthora

diseases. This research received financial backing from European

chocolate makers through the Caobisco association.

This overview presents the results obtained in work undertaken

during the project. Its main purpose is to provide the international

community with knowledge and tools that can be used to breed

cocoa trees with greater resistance to Phytophthora.

Improvement of cocoa tree resistance to Phytophthora diseases

covers pathogen diversity, epidemiological knowledge, the genetic

parameters of resistance observed in the field, and practical

breeding aspects. The relevance of different screening tests

involving artificial inoculations and the use of molecular markers

for the selection of resistant material are widely covered.