A flat petal as ancestral state for Ranunculaceae

Area of Science:

• Evolutionary developmental biology
• Plant morphology
• Ranunculaceae family

Background:

• Ranunculaceae exhibit significant floral diversity, especially in petal morphology.
• Petals in this family are often elaborate, nectar-producing structures vital for pollination.
• This diversity makes Ranunculaceae an excellent model for studying the evolution of complex floral traits.

Purpose of the Study:

• Reconstruct the ancestral petal form and evolutionary stages within Ranunculaceae.
• Investigate if common morphogenetic regions explain petal diversity across species.
• Test hypotheses on the developmental basis of petal morphological variation.

Main Methods:

• Analyzed petal morphology traits in 32 genera.
• Described petal development using high-resolution X-ray computed tomography (HRX-CT) in six species.
• Performed ancestral state reconstruction on a dated phylogeny of the family.

Main Results:

• The ancestral petal for most Ranunculaceae was likely flat with a short claw.
• Elaborate petals evolved independently in different lineages.
• Convergent evolution explains similar petal morphologies observed across various species.

Conclusions:

• Petal evolution in Ranunculaceae is characterized by independent acquisition of elaborate forms.
• Developmental processes, potentially involving proportions of common morphogenetic regions, drive diversity.
• Ancestral state reconstruction provides new insights into petal evolution within this family.