Comparing Patterns of Flower Evolution in Diploid and Polyploid Nicotiana Species

Authors: Marissa McLean, Elizabeth McCarthy, Mark Chase, Corinne Mhiri, Marie-Angele Grandbastien, Kendra Muscato, Pam Soltis, Doug Soltis

SUNY Campus: SUNY Cortland

Presentation Type: Poster

Location: Old Union Hall

Presentation #: 27

Timeslot: Session A 9:00-10:00 AM

Abstract: Allopolyploids are hybrids of their progenitors and experience a whole genome duplication. Nicotiana section Suaveolentes originated from a polyploidization event six million years ago and have since speciated into ~90 species. There is a variety of different shapes and sizes of the flowers within the section and most have been found in Australia with some from Oceania and one from Africa. My research mentor and I traveled to the Royal Botanical Gardens, Kew, UK in Summer 2024 to capture photos of the flowers. Measuring flower tube length and width from our photos was integrated into introductory biology labs in both the Fall 2024 and Spring 2025 semesters. We used these data from the polyploids and previous data from diploids for ancestral character state reconstructions to assess patterns of evolution. We compared results from diploids and polyploids to determine the effect of polyploidy on evolutionary trajectories. The effect of polyploid age on flower size was also analyzed using synthetic N. tabacum lines made in a lab by our collaborators in Versailles, France. Different generations were compared using F1 flowers that were diploid hybrids and S0 flowers that were created after inducing F1 flowers to duplicate their genome. For both flower tube length and width, the S0 allopolyploid hybrids were significantly larger, supporting our hypothesis that because there is more genetic information in the cells, the flowers are bigger. Trajectories of F1 to S0 lines were compared to trajectories of Nicotiana section Suaveolentes to analyze the effect of age on allopolyploid evolution.