Novel computed tomography-based tools reliably quantify plant reproductive investment

Area of Science:

• Botany
• Reproductive Biology
• Ecology

Background:

• Flowers are bisexual reproductive units with competing male and female resources.
• Accurate pollen and ovule counts are crucial for understanding gender investment.
• Traditional methods struggle with aggregated pollen and unknown fertilization rates.

Purpose of the Study:

• To develop novel counting techniques for pollen and ovules using computed tomography.
• To demonstrate the method's efficacy in challenging cases like European orchids.
• To compare reproductive investment between deceptive and rewarding pollination strategies.

Main Methods:

• Utilized computed tomography (CT) for precise pollen and ovule quantification.
• Applied new CT-based techniques to European orchid inflorescences.
• Analyzed pollen counts, ovule numbers, and pollen-to-ovule ratios.

Main Results:

• Pollen counts showed no significant variation across inflorescences or pollination strategies.
• Deceptive flowers exhibited significantly higher ovule numbers compared to rewarding flowers.
• Rewarding flowers displayed a fourfold greater variance in pollen-to-ovule ratios than deceptive flowers.

Conclusions:

• Novel computed tomography methods overcome limitations of classical techniques for counting aggregated pollen and ovules.
• Findings suggest differences in reproductive investment constraints between deceptive and rewarding pollination strategies in orchids.
• The new techniques offer broad applicability for measuring reproductive investment without specimen destruction.