3rd Edition of Agriculture, Forestry, and Horticulture World Conference 2027

Abstract

Arbuscular mycorrhizal fungi (AMF) play a crucial role in the nutrition, growth, and resilience of cacao plants (Theobroma cacao L.). This study assesses the impact of introducing an exogenous strain of Rhizophagus irregularis on the growth of young cacao plants and on the structure of endomycorrhizal communities. Young cacao plants were cultivated in pots under greenhouse conditions, partially controlled. Total DNA was extracted from substrate samples and analyzed by PCR using two pairs of specific primers (AML1/AML2 and NS31/AM1), followed by sequencing on the Illumina MiSeq platform. Agronomic, molecular, and phylogenetic analyses revealed that, compared to the exogenous strain, indigenous AMF more effectively enhanced growth parameters (height, stem diameter, biomass, and leaf area) and maintained a higher fungal diversity, notably with a dominance of Glomus and Acaulospora. Introducing R. irregularis reduced species richness and altered the structure of local AMF communities, favoring the dominance of this species at the expense of endemic symbionts. These findings confirm the importance of local AMF in supporting cacao productivity and resilience, raising questions about the long-term ecological and agronomic implications.

Keywords: Arbuscular Mycorrhizal Fungi, Rhizophagus irregularis, Cacao, Diversity, Tropical Agriculture