Erika R. Olmedo Vicente. University of Seville. Supervisors: Juan Arroyo. Start in 2015.
Summary:
Hybridization is a major evolutionary force in plants. It
can be a reproductive isolating barrier and thus a driver for
differentiation (i.e. homoploid hybrid speciation or
allopolyploidization). However, the homogenizing effects of gene flow
and outbreeding depression can also slow or reverse the speciation
process. Yet, hybridization can be avoided by the sequential actions of
pre and postzygotic barriers. For example, it has been recognized that
ecological barriers can play an important role in preventing
hybridization, however, when these barriers are overcome, differences in
the mating system and the reproductive biology of the interacting
species could prevent the formation of the F1 generation. Moreover, when
all these barriers are surpassed and hybrids are formed, post-zygotic
barriers can prevent their establishment. In this context, we are
interested in determine the strength of ecological, reproductive and
genetic isolation barriers in two Linum sister species. Linum
suffruticosum and L. tenuifolium posses contrasting self-incompatibility
systems and it has been suggested that they could naturally hybridize in
their extensive contact zone (500 km in NW Mediterranean Basin). To
accomplish this, we will use, ecological niche modeling, experimental
reproductive approaches and morphological and genetic analysis to
understand how the species boundaries are maintained in a hot spot of
biodiversity such as the Mediterranean Basin.