title: Genome size variation and incidence of polyploidy in Scrophulariaceae sensu lato from the Iberian Peninsula.
abstract: OBJECTIVE
  In the last decade, genomic studies using DNA markers have strongly influenced the current phylogeny of angiosperms. Genome size and ploidy level have contributed to this discussion, being considered important characters in biosystematics, ecology and population biology. Despite the recent increase in studies related to genome size evolution and polyploidy incidence, only a few are available for Scrophulariaceae. In this context, we assessed the value of genome size, mostly as a taxonomic marker, and the role of polyploidy as a process of genesis and maintenance of plant diversity in Scrophulariaceae sensu lato in the Iberian Peninsula.
  
  
  METHODS
  Large-scale analyses of genome size and ploidy-level variation across the Iberian Peninsula were performed using flow cytometry. One hundred and sixty-two populations of 59 distinct taxa were analysed. A bibliographic review on chromosome counts was also performed.
  
  
  RESULTS
  From the 59 sampled taxa, 51 represent first estimates of genome size. The majority of the Scrophulariaceae species presented very small to small genome sizes (2C ≤ 7.0 pg). Furthermore, in most of the analysed genera it was possible to use this character to separate several taxa, independently if these genera were homoploid or heteroploid. Also, some genome-related phenomena were detected, such as intraspecific variation of genome size in some genera and the possible occurrence of dysploidy in Verbascum spp. With respect to polyploidy, despite a few new DNA ploidy levels having been detected in Veronica, no multiple cytotypes have been found in any taxa.
  
  
  CONCLUSIONS
  This work contributed with important basic scientific knowledge on genome size and polyploid incidence in the Scrophulariaceae, providing important background information for subsequent studies, with several perspectives for future studies being opened.
authors.affiliation: CFE, Centre for Functional Ecology, Department of Life Sciences ,  University of Coimbra ,  PO Box 3046, Coimbra 3001-401 ,  Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Castro
authors.forename: Sílvia
authors.initials: S
authors.lastname: Castro
authors.forename: João
authors.initials: J
authors.lastname: Loureiro