Amino acids , carbohydrates and heritability of resistance in the Theobroma cacao / Phythophthora megakarya interaction

Cocoa (Theobroma cacao L.) is a commodity produced in the developing countries of the tropics. It is mainly consumed in the middle and high income countries of the world’s temperate zone. Currently, over 50 countries are engaged in cocoa production and heavily rely only on cocoa exportation for their economic development, as this commodity contributes significantly to foreign exchange earnings. However, Phytophthora pod rot (Ppr), caused by Phytophthora palmivora, P. megakarya, P. capsici and P. citrophthora, is one of the prevalent and destructive diseases of cocoa (Iwaro et al., 1997). Global losses from Ppr are very great, and have been estimated by Wood and Lass (1985) at about 30% of annual production. The selection criteria used for development of new cocao varieties in the 1960s were based on the yield earliness and bean weight. Resistance to disease, based on field observations, was taken into account only as a secondary selection criterion. Consequently, the develop