Floral Volatiles of Maldivian Mangroves: Insights into Unexplored Chemotypes and Pollinator Interactions

Volatile organic compounds (VOC) emitted by flowers are key drivers of pollinator attraction and plant reproductive success. Despite the ecological importance of mangroves, their floral VOCs are still largely unexplored. Here, we report the floral VOC profiles of eight mangrove species from the Maldivian archipelago, where the related ecosystems are critically endangered. Specifically, we analyzed Ceriops tagal, Bruguiera cylindrica, and Rhizophora mucronata, for which no previous floral scent reports are available worldwide, together with Avicennia marina, Lumnitzera racemosa, Pemphis acidula, Bruguiera gymnorrhiza, and Rhizophora apiculata. A total of 949 distinct molecular features were individuated by untargeted GC-MS analysis. 27 were confidently annotated on the basis of NIST library match score (>90%). Multivariate statistical analysis revealed a species-dependent organization of floral scent bouquets, with mangrove taxa differing both in the degree of olfactory distinctiveness and in intra-species chemical variability. C. tagal was characterized by 2-phenylethanol and other volatiles commonly associated with moth attraction, whereas B. cylindrica emitted linalool, phenylacetaldehyde, and (E)-4,8-dimethyl-1,3,7-nonatriene, compounds typically linked to a broader range of insect visitors. R. mucronata, traditionally regarded as wind-pollinated, unexpectedly released several VOCs known to attract bees, moths, flies, and beetles. Overall, by providing a first chemical baseline, this work aims to improve the understanding of mangrove reproductive ecology and to support sustainable management of Maldivian mangrove ecosystems.