Geographic variation of fruit scents in a dispersion mutualism,the case of Ficus lutea

Chemical mediation is often involved in interactions between plants and animals, as in pollination and in seed dispersion mutualisms. Extensive investigation has been done in floral scents and on their interspecific and intraspecific variations, but similar research on fruit scent remains poorly explored and only focused on interspecific variations. We investigated in this study the intraspecific variations of volatile bouquet emitted by mature fruits of Ficus lutea, in two sites within its wide distribution range, i.e. in South Africa and in Madagascar. We demonstrated a clear geographic variation in the volatile bouquet emitted by ripe figs in these two study sites, especially due to the presence of sesquiterpenes in Madagascan bouquets, while scents present at both sites high amounts of fatty acid derivatives. We discuss here different possible explanations for such variations in fruit scents, potentially resulting from insular and/or geographic isolation. This novel result of an intraspecific variation linked to fig seed dispersion serves to increase our knowledge of the role of scents in seed dispersal mutualisms.