Nectar metabolomics of two neotropical spiral gingers with contrasting pollination vectors

Resumen

In spiral gingers, Costaceae, floral morphology evolved in correlation with two contrasting pollination vectors: ornithophilous species have red tubular flowers that attract hummingbirds, while melittophilous species have flowers with open labellum bearing nectar guides attractive to bees. Here, we characterize the metabolite profile of nectar from two Neotropical species of Costaceae to understand how nectar composition relates to pollination. Nectar samples collected from Costus arabicus, a melittophilous species, and Costus juruanus, an ornithophilous species, were prepared for gas chromatography coupled with mass spectrometry. To identify sugar metabolites, saccharide standards were prepared. Results show that sucrose is the predominant sugar in both species, with 2.2 % difference in concentration between the two species. Nevertheless, C. juruanus exhibits higher levels of fructose (205.79 %), while C. arabicus has higher concentrations of sorbitol (66.67 %), myo-inositol (200 %), and glucose (94 %). We found no traces of other metabolites commonly found in nectars, such as amino acids, lipids and esters. Despite being pollinated by strikingly different vectors, the species analyzed here offer a similar resource to their pollinators. This result is consistent with macroevolutionary analyses of other pollination traits that indicate melittophilous morphology as primitive in this family's history, while hummingbird pollination evolved repeatedly from melittophilous ancestrals.

Citation: Satos, Y.V., Williams, T.C.R. & André, T. 2025. Nectar metabolomics of two neotropical spiral gingers with contrasting pollination vectors. Revista Jard. Bot. Nac. Univ. Habana 46 (Número especial 1): 122.

Trabajo presentado en el XIII Congreso Latinoamericano de Botánica. Sesión Estructura, Fisiología y Desarrollo.