Assessing relationship between phenolic compounds and resistance t<i>Phytophthora megakarya</i> using two cocoa (<i>Theobroma cacao</i>) families

Abstract

Black pod disease is an important fungal infection in cocoa (Theobroma cacao L.) which causes high production losses. In Cameroon, these losses reached 80% of cocoa production depending on ecological zones. In order to contribute to the efficiency of selection methods used in resistance or tolerance to black pod disease with the aim of improving on cocoa farming, the content of phenolic compounds was analyzed on the genotypes of two hybrid families (F79:♀T_79/467x♂SNK₁₃ and F13:♀SNK₁₃x♂T_79/467) of cocoa which are different in productivity and vulnerability to black pod disease. After artificial inoculation of the pods by mycelium of Phytophthora megakarya, the content of the phenolic compounds significantly increased in all genotypes of the two families. The heterosis effect of each family revealed a higher variability within both families. These results alike showed that productive and tolerant genotypes (F1307, 1314, F7902 and F7928) have a high phenols content and positive heterosis meanwhile the less tolerant and productive genotypes (F1321, F1326, F7904 and F7911) have a weak content and negative heterosis

Keywords: Cocoa, disease, tolerance, heterosis effect, phenolic compounds, hybrid progenies

African Journal of Biotechnology Vol 13(29) 2956-2965