Abstract Detail

Development and Structure

Selby, Reid [1], Jones, Daniel [1].

Bidens as a model system for studying capitulum development and floral evolution.

The Asteraceae are easily identified by their highly compressed inflorescences known as capitula, in which many florets comprise a head that functions as a single floral unit, called a pseudanthium (or “false flower”). Few lab-ready model systems exist to study the underlying genetics of capitulum development and evolution, as many Asteraceae species have large genomes, no tractable transformation protocols, and require extensive resources for continual seed to seed cultivation. In the CapituLab at Auburn, we are working toward adapting the cultivated ornamental Bidens ferulifolia as a new model system to study capitulum development and evolution. B. ferulifolia is a promising candidate for a model due to its relatively small diploid genome, compact growth habit, quick growth rate, and ease of vegetative propagation. B. ferulifolia is also readily adaptable to tissue culture, and the CapituLab is developing in vitro transformation methods via Agrobacterium tumefaciens. Additionally, we are generating reference quality genomes for B. ferulifolia using long-read DNA sequencing (PacBio HiFi) coupled with HiC chromatin mapping. A chromosome-scale genome assembly combined with transformation capabilities in B. ferulifolia provide powerful tools for a genetic model system in studying capitulum development. Beyond insights into the Asteraceae as a whole, B. ferulifolia also enables an interesting means of studying phenotypic radiation. B. ferulifolia is a North American relative to the well-studied Hawaiian Bidens adaptive radiation. While the genus only colonized the Hawaiian Islands relatively recently, the 19 species found there display higher trait diversity than the approximately 230 remaining species. This classic example of adaptive radiation provides an interesting context in which to explore evolution and development of capitulum morphology. All Hawaiian Bidens are hexaploid and many are protected due to their conservation status. B. ferulifolia as a model system will allow us to ask questions about the underlying genetics linked to phenotypic variability and species expansions in the Hawaiian Bidens complex that were previously impractical to pursue. Overall, the genus Bidens provides an excellent framework for asking key evolutionary questions about rapid phenotypic expansion in a tractable model system.

1 - Auburn University, 101 Life Sciences Building, 332, Auburn, Alabama, 36849, USA

Keywords:
Asteraceae
Floral Development
Bidens
tissue culture
comparative genomics.

Presentation Type: Poster
Number: PDS010
Abstract ID:465
Candidate for Awards:Developmental and Structural Section best poster