title: Geometric morphometrics of corolla shape: dissecting components of symmetric and asymmetric variation in Erysimum mediohispanicum (Brassicaceae).
abstract: Symmetry is an important feature of floral structure, and floral symmetries are diverse and often complex. We use a new morphometric approach for analysing shapes with complex types of symmetry, which partitions shape variation into a component of symmetric variation and different components of asymmetry. This approach, based on the mathematical theory of symmetry groups, can be used for landmark configurations with any type of symmetry and is therefore promising as a general framework for morphometric analyses of floral symmetry and asymmetry. We demonstrate this approach by quantifying floral shape variation in a wild population of Erysimum mediohispanicum (Brassicaceae). Flowers of this species are disymmetric, so that the symmetry in the left-right and adaxial-abaxial directions can be considered separately and in combination. Both principal component analysis and Procrustes ANOVA indicate that symmetric variation accounts for most of the total variance and that adaxial-abaxial asymmetry is the dominant component of fluctuating asymmetry. Each component is associated with specific patterns of shape variation. These results illustrate the potential of the new method and suggest new areas for future research. The new morphometric approach is promising for further analyses of floral symmetry and asymmetry in evolutionary and developmental contexts.
authors.affiliation: Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK.|UMR 7205 CP 50 Entomologie/service Hyménoptères, Muséum National d'Histoire Naturelle, 45 rue Buffon, 75005, Paris, France.|Department of Biological Sciences St. Albert Hall, Rm 272 St. John's University, 8000 Utopia Parkway Queens, NY, 11439, USA.
authors.forename: Yoland
authors.initials: Y
authors.lastname: Savriama
authors.affiliation: Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, E-18071, Granada, Spain.
authors.forename: José María
authors.initials: JM
authors.lastname: Gómez
authors.affiliation: Departamento de Genética, Facultad de Ciencias, Universidad de Granada, E-18071, Granada, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Perfectti
authors.affiliation: Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK.
authors.forename: Christian Peter
authors.initials: CP
authors.lastname: Klingenberg
mesh_terms: D000704:Analysis of Variance; D005075:Biological Evolution; D019295:Computational Biology / Q000379:methods*; D032601:Erysimum / Q000033:anatomy & histology* / Q000254:growth & development; D035264:Flowers / Q000033:anatomy & histology* / Q000254:growth & development; D063245:Plant Development; D025341:Principal Component Analysis; D013045:Species Specificity