Abstract Detail

Systematics Section/ASPT

McCarthy, Elizabeth [1], Arnold, Sarah [1], Le Comber, Steven  [1], Verity, Robert [1], Dodsworth, Steven [1], Chittka, Lars [1], Knapp, Sandra [2], Kelly, Laura [3], Chase, Mark [4], Baldwin, Ian [5], Kovarik, Ales [6], Mhiri, Corinne [7], Taylor, Lin [8], Leitch, Andrew [1].

Evolution of floral morphology in Nicotiana allopolyploids of different ages.

The evolution of floral morphology in Nicotiana (Solanaceae) allotetraploids, ranging from a few generations (synthetic allotetraploids) to ~4.5 million years old, was examined using geometric morphometrics of floral limb shape, corolla tube length and width, and spectral reflectance measurements of floral color.  In floral limb shape, younger polyploids tend to be intermediate in shape between their diploid progenitors, whereas older polyploids have more divergent forms.  However, divergence in shape can occur rapidly following allopolyploidization.  Most of the polyploids examined have shorter and wider corolla tubes than expected, suggesting more generalist pollination following allopolyploidization.  Floral color was analyzed using the spectral reflectance of petal tissue from 300-700 nm as well as models of insect and hummingbird color perception, two known pollinator types of Nicotiana species, based on these spectra.  Floral color is not entirely constrained by phylogeny, and allopolyploids can display a floral color like one or other diploid progenitor or a divergent color.  The floral color of N. tabacum is divergent and seems to have resulted from the inheritance of floral plastids which lack chlorophyll from its maternal progenitor and the inheritance of anthocyanin pigmentation from its paternal progenitor.  Overall, the combined study of floral shape, size, and color in Nicotiana sheds light on the evolution of allopolyploids in the context of pollination.

1 - Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London, E1 4NS, UK
2 - Natural History Museum, London, SW7 5BD, UK
3 - Royal Botanic Gardens, Kew, Jodrell Laboratory, Kew, Richmond, TW9 3DS, UK
4 - Royal Botanic Gardens - Kew, Jodrell Laboratory, Kew Road, Richmond, N/A, TW9 3DS, United Kingdom
5 - Max Planck Institute for Chemical Ecology, Department of Molecular Ecology, Beutenberg Campus, Hans-Knoll-Str. 8, Jena, 07745, Germany
6 - Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, CZ-61625, Czech Republic
7 - Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, INRA-Versailles, Versailles cedex, 78026, France
8 - University of Cambridge, Department of Plant Sciences, Downing Street, Cambridge, CB2 3EA, UK

Keywords:
polyploidy
geometric morphometrics
flower color
pollination
Evolution
Nicotiana.

Presentation Type: Oral Paper:Papers for Sections
Session: 44
Location: Firs North/Boise Centre
Date: Wednesday, July 30th, 2014
Time: 4:15 PM
Number: 44010
Abstract ID:712
Candidate for Awards:Margaret Menzel Award