Developmental and Structural Section
Bissell, Erin , Diggle, Pamela K. .
Floral morphology in Nicotiana: Are character correlations lost in space and time?
Nicotiana alata and N. forgetiana are sister species that differ dramatically in floral shape and size and these aspects of morphology correspond to differences in pollinators. In addition to interspecies variation in floral morphology, there is potential for considerable intraspecies variation as well. In particular, differences due to position along a shoot (architectural) and/or flower age (temporal) are common within and between inflorescence axes in many plant species. These sources of variation have the potential to confound comparative analyses of floral morphology. As part of a larger study of floral evolution in Nicotiana, we examined architectural and temporal effects on several floral traits as well as correlations among them. Flowers were collected from the two species and third generation artificial hybrids. The floral traits measured either did not vary or they exhibited two general trends. Trait values decreased distally along a cyme as well as basally along a shoot and increased with flower age. Because patterns of correlation among traits are important to the larger question of evolutionary change among the species, we conducted a factor analysis in order to test for effects of position and flower age on correlation structure. None of the taxa showed differences in phenotypic correlation patterns due to position or age, suggesting that character change among correlated characters is coordinated.
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1 - University of Colorado, Department of Ecology and Evolutionary Biology, UCB 334, Boulder, Colorado, 80309, USA
Presentation Type: Oral Paper
Location: Salon A - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 11:30 AM