Polinización y reproducción en especies de "Scrophularia" de flores grandes y vistosas del Viejo Mundoperspectivas ecológicas y moleculares

Résumé

This thesis is focused on the study of the floral biology, pollination and breeding system of some species of the genus "Scrophularia", linking these aspects with phylogenetic and biogeographic studies. In this way, it is demonstrated the existence of a mixed insect-bird pollination system for species with large and showy flowers ("S. grandiflora", "S. sambucifolia", "S. trifoliate" y "S. calliantha"). For the first three species, in addition, it has been evidenced the necessity of participation of pollinators in order to get a successful sexual reproduction, as well as the self-compatibility of them. From the floral biology point of view, either than in the mentioned species as in others phenotypically different, there are no differences on sugar composition and in presence of microorganism communities therein. In all of them nectar is rich in sucrose, except for the Canarian "S. calliantha" where is balanced; additionally, there is a low quantity and diversity of yeasts in them. Regarding to the phylogenetic reconstruction of pollination systems in the genus, it is concluded that the wasp system would be the ancestral one, from which the others have been derived, while the mixed system is recent and also is considered successful since it was acquired four times independently on different islands and continents. Finally, phylogenetic reconstruction of ancestral areas shows that there have been multiple windows of colonization to Macaronesia despite being a genus without specialized dispersal system.