Estudio taxonómico y evolutivo de la subtribu Anthoxanthinae (Poaceae; Pooideae)

Abstract

The subtribe Anthoxanthinae (Poaceae; Pooideae; Poeae) is composed by two genera closely related phylogenetically, Anthoxanthum and Hierochloë, whose taxonomic ascription remains a source of controversy. Nevertheless, it has been considered a good model organism for the study of the recent evolution of C3 grasses due to its incomplete morphological differentiation, wide geographic distribution and cytogenetic structure. In this Doctoral Thesis different methods are used to contribute to clarify the taxonomy and establish the phylogenetic relationships among the members of the Anthoxanthinae subtribe. To achieve the objectives of this study, multivariate statistical methods were used for the treatment of morphological data, phylogenetic analyses were applied to process molecular data, microsatellite markers were developed and genomic size was determined by flow cytometry and related to ploidy levels. First, a study of the subtribe was conducted integrating morphological, ecological, cytogenetic and molecular data to clarify its evolutionary history (including general biogeographic patterns) and its taxonomic organization (chapter 1). Later, the section Monoecia of the genus Hierochloë, a model for the diversification of C3 plants in the Andes, was studied thoroughly (chapter 2). Then, the taxonomic revision of this section (chapter 3) and the Iberian species of the genus Anthoxanthum (chapter 4) were conducted. Finally, specific non-plastid molecular markers (microsatellites) have been developed for the species of the Eurosiberian complex of the genus Anthoxanthum, selecting 15 pairs of primers obtained from a preliminary test performed with the diploid lineages of the Mediterranean diploid A. aristatum/A. ovatum (chapter 5).