IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Style morphological diversity of some Asteraceae species from Argentina: systematic and functional implications
Autor/es:
CAROLINA TORRES; GALETTO LEONARDO
Revista:
International Journal of Plant Research
Editorial:
Springer
Referencias:
Lugar: Japón; Año: 2006 vol. 120 p. 1 - 1
Resumen:
Stylar micromorphological diversity of 42 Asteraceae species from Argentina was analysed considering
species phylogenetic membership and some floral reproductive functions (pollen presentation and pollen
reception). In particular, the morphology and organisation of pollen presenter (sweeping hairs) and pollen
receptive structures (stigmatic papillae) were described. Results showed that style morphology of the studied
species is far more diverse than the categories previously established for Asteraceae, and that it is problematic
to relate the sweeping-hair arrangement of species to the only three modes of pollen presentation described
for the family, indicating that the hypothesised relationship could be more complex than was formerly thought.
For all species with di- or trimorphic florets, the styles of female florets were more slender and without or
with more reduced sweeping hairs than the styles of hermaphrodite florets, and divergences of sweeping hair
arrangements and morphology were higher among phylogenetically related species. These results suggest
that functional aspects of floral morphology seem to be more important than phylogenetic constraints as
selective forces determining stylar pollen presentation structures. In contrast, stigmatic-area organisation as
well as the morphology of stigmatic papillae remain identical between female and hermaphrodite florets and
among phylogenetically related species. Thus, stigmatic papilla morphology seems to be a phylogenetically
constrained character in the studied species.