Wild origins, cultivated undertones: floral scent variation in Vanilla planifolia Andrews

Floral scent is a key trait mediating plant-pollinator interactions, yet the extent to which cultivation alters floral scent remains poorly explored. We investigated the floral scent profile of Vanilla planifolia Andrews, a Neotropical orchid of major economic importance, and compared wild and cultivated individuals to assess the effects of horticultural conditions relative to the species' natural environment. Floral scent samples were collected from individuals of a single wild population in Costa Rica and from ex-situ plants originating from the same population but maintained at Lankester Botanical Garden.

A total of 31 volatile organic compounds were detected in the samples analysed using gas chromatography coupled to mass spectrometry (GC/MS), with 2-tridecanone, 1,8-cineole, and (E)-β-ocimene dominating the scent profile. Multivariate analyses revealed that qualitative scent composition was largely similar between wild and cultivated plants, while semiquantitative scent composition - reflecting relative compound abundances - differed significantly. The floral scent of wild plants was dominated by 2-tridecanone and 2-pentadecanone, while cultivated plants exhibited a strong dominance of 1,8-cineole; both groups contained high proportions of (E)-β-ocimene. Furthermore, wild plants showed higher functional evenness, suggesting a more evenly structured and potentially more robust scent profile.

Our findings demonstrate cultivation-associated shifts in floral scent expression without loss of qualitative compound composition, highlighting environmental plasticity in a key trait mediating plant-pollinator interactions. We encourage future research to explore how changing climatic conditions may further influence Vanilla scent profiles and how this may affect pollinator attraction, pollination success, and plant reproduction; processes essential for plant persistence and ecosystem stability in a rapidly changing world.