Dissemination modes in the dispersal processes of coryphoid palms: ecological anatomy of endozoochorous diaspores

The plant-animal interactions are among the most important problems to analyze in biogeography and ecology. A key research area is endozoochory, the study of which allows identifying the local dynamics of plant communities, as well as revealing and modelling long-distance dispersal pathways, enabling plants to colonize new areas and migrate in response to environmental changes. The subfamily Coryphoideae (Arecaceae, или Palmae), the most widespread subfamily of palms, was chosen as an object of study. Palms are an extensively studied group, but despite the increasing number of detailed investigations, data on Coryphoideae fruits and their dispersal processes remain incomplete. Therefore, there is a significant need for a detailed study of the dispersal modes of coryphoid palms and their adaptations to dissemination. The aim of our study is to identify and analyze the fruit structure traits in Coryphoideae species distributed across different regions of the world and adapted to dissemination by various dispersal agents. The morphological and anatomical structure traits of 25 model coryphoid palm species were studied using standard comparative carpological and carpobiological methods. We revealed that fruits of the studied species demonstrated significant morphological and anatomical adaptations to endozoochorous dissemination attracting various dissemination agents (fruit colour and size, nutrients supply in the pericarp cells) and ensuring seed protection (sclerified structures and raphides in the mesocarp). We presume that among the studied taxa, species forming small or medium-sized, contrast-coloured fruits with protective structures in the pericarp are the most adapted to endozoochory. Adaptations to endozoochorous dispersal are less effective in Coryphoideae species with large, dull-coloured fruits and just an outer belt of sclereids in the mesocarp.

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