Using geometric morphometrics to determine the “fittest” floral shape: A case study in large-flowered, buzz-pollinated Meriania hernandoi

Autor(en)

Agnes S. Dellinger, Daniela Hanusch, Mario Oswald, Diana Fernández-Fernández, Jürg Schönenberger

Abstrakt

Abstract Premise Floral shape (relative arrangement and position of floral organs) is critical in mediating fit with pollinators and maximizing conspecific pollen transfer particularly in functionally specialized systems. To date, however, few studies have attempted to quantify flowers as the inherently three-dimensional (3D) structures they are and determine the effect of intraspecific shape variation on pollen transfer. We here addressed this research gap using a functionally specialized system, buzz pollination, in which bees extract pollen through vibrations, as a model. Our study species, Meriania hernandoi (Melastomataceae), undergoes a floral shape change from pseudocampanulate corollas with more actinomorphically arranged stamens (first day) to open corollas with a more zygomorphic androecium (second day) over anthesis, providing a natural experiment to test how variation in floral shape affects pollination performance. Methods In one population of M. hernandoi, we bagged 51 pre-anthetic flowers and exposed half of them to bee pollinators when they were in either stage of their shape transition. We then collected flowers, obtained 3D flower models through x-ray computed tomography for 3D geometric morphometric analyses, and counted the pollen grains remaining per stamen (male pollination performance) and stigmatic pollen loads (female pollination performance). Results Male pollination performance was significantly higher in open flowers with zygomorphic androecia than in pseudo-campanulate flowers. Female pollination performance did not differ among floral shapes. Conclusions These results suggest that there is an ?optimal? shape for male pollination performance, while the movement of bees around the flower when buzzing the spread-out stamens results in sufficient pollen deposition regardless of floral shape.

Organisation(en)

Department für Botanik und Biodiversitätsforschung, Department für Funktionelle und Evolutionäre Ökologie, Department für Evolutionsbiologie

Externe Organisation(en)

Instituto Nacional de Biodiversidad

Journal

American journal of botany

Band

110

Anzahl der Seiten

15

ISSN

0002-9122

DOI

https://doi.org/10.1002/ajb2.16183

Publikationsdatum

06-2023

Peer-reviewed

Ja

ÖFOS 2012

106008 Botanik, 106012 Evolutionsforschung, 106042 Systematische Botanik

Schlagwörter

ASJC Scopus Sachgebiete

Genetics, Ecology, Evolution, Behavior and Systematics, Plant Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/9acf5d99-6d1f-41cb-ba56-f3451a30be47