Home PhD dissertations

The role of polyploidy in shaping the diversity within the Linum tenuifolium s.l. (Linaceae)

Ana Afonso, University of Coimbra and University of Seville. Supervisors: João Loureiro, Sílvia Castro, Juan Arroyo. Start in 2016.
Summary:
Polyploidy is widespread in angiosperms and has long been considered as an important mechanism of speciation. Genome duplications bear broad-scale consequences on gene expression and developmental processes, potentially leading to immediate morphological, reproductive and physiological shifts. Despite the advances in the genetic and epigenetic consequences of genome duplications, the ecological factors driving polyploidy and its evolutionary consequences are poorly understood. The main objective of this PhD project is to explore the relationship between polyploidy and biological and ecological traits driving plant divergence. For that, it will be used the Linum tenuifolium s.l. group, a diploid-polyploid complex that presents monomorphic and heteromorphic populations and widely unexplored contact zones between cytotypes. The complexity and geographical setting of this group offers a unique opportunity to explore the relationship between ploidy levels and reproductive strategies, namely, how polyploidy relates with floral polymorphisms (heterostyly), breeding system (self-compability and self-incompatibility) and ability to hybridize. A vaster ecological and evolutionary framework will also be pursued, not only to disentangle the relationship between polyploid and ecological niche differentiation and competitive ability, but also to clarify the phylogenetic and phylogeographic relationships between the taxonomic entities of this group. Overall, this project will enable to understand how polyploidy may affect several biological and ecological traits that may be involved in plant diversification and evolution, contributing with relevant clues for the better comprehension of the adaptive value of polyploidy.