Perianth organization and intra-specific floral variability

Area of Science:

• Plant reproductive biology
• Evolutionary ecology
• Floral morphology

Background:

• Floral traits like symmetry and petal fusion influence pollination.
• Pollinators exert stabilizing selection, favoring consistent floral displays.
• Understanding these relationships is key to floral evolution.

Purpose of the Study:

• To investigate if fused petals (sympetalous) and bilateral symmetry decrease intra-specific variation.
• To determine if these floral traits are indicators of stabilizing selection by pollinators.
• To test evolutionary hypotheses linking floral morphology to phenotypic constancy.

Main Methods:

• Assessed corolla size and intra-specific variation in southern Spanish entomophilous plants.
• Used phylogenetically independent contrasts to control for evolutionary relatedness.
• Analyzed data from a previous study on petal fusion and flower size.

Main Results:

• Bilaterally symmetrical flowers showed significantly less intra-specific variation than radially symmetrical flowers.
• Petal fusion showed a non-significant trend towards reduced variation.
• Results were consistent when reanalyzing previous data, but not in a randomly selected sample.

Conclusions:

• Floral symmetry is a significant factor in reducing intra-specific variation under pollinator selection.
• Petal fusion's role in stabilizing floral traits is less clear and requires further investigation.
• Low statistical power and trait correlations may affect evolutionary hypothesis testing in floral studies.