Climate, phenology, genetics and embryogenesis in Theobroma cacao L

To optimize somatic embryogenesis, effects of some climatic, phenological, explants, culture media and genetic factors were analysed. Means comparison via Anova, linear correlations, principal component analysis and multiple linear regression were run. Climatic and phenological factors were organized in periods and phenological classes, respectively. During the 2 years of study, temperature gaps, fructification and flowering levels were accounted for fewer than 10% embryogenesis fuctuations. So, climate and phenology weakly influence somatic embryogenesis. Petals effect was more embryogenic than that of staminodes. The most PCG4 concentrated medium expressed an effect more embryogenic than PCG1 and PCG3. L233-A4, L120-A2, L126-A3, L231-A4 and L330-A9 hybrids, C151-61 and SCA6 control clones as well as Pa121, IMC67, P19A and Pa13 parents were chosen for callogenesis. As for somatic embryogenesis, L126-A3, L231-A4 and L120-A2 hybrids, SCA6 and C151-61 control clones, Pa13 and P19A parents were selected. Callogenic and embryogenic abilities from hybrids were like those from parents. Staminodes and petals in co-culture interacted for callogenesis, but not for somatic embryogenesis.

Autorentext

Auguste Emmanuel ISSALI, is Forestry Engineer and Doctor in Plant Breeding from the Abidjan-Cocody University. He is Head of Coconut Breeding Department at the Marc Delorme Coconut Research Station based on Port Bouët in Côte d'Ivoire. He is also Regional Coordinator of the International Coconut Genetic Resources Network for Africa and Indian Ocean