Mediterranean Firs: A Complete Next-Generation Sequencing Phylogeny

Some molecular phylogenetic studies were conducted for Abies Mill. either by including a limited set of species or by using only data from a few markers of a single genome (from chloroplast, mitochondrial or nuclear ribosomal DNA). Here we present the first complete molecular phylogeny of a tree genus, Abies, in the Mediterranean. The application of sequencing of restriction-site-associated DNA tags (RADseq), a next-generation sequencing-based method, provided highly valuable information to assess the position of the different Abies species in the study area. Over 6,000 filtered SNPs produced a well-supported phylogenetic tree and confirmed species delimitations. Additionally, we obtained a well-resolved molecular phylogeny that corroborated the monophyletic origin of all the Mediterranean firs as well as their separation in the two sections previously recognized, sect. Abies and sect. Piceaster. Finally, the evolutionary history of the Mediterranean firs appeared to show frequent interspecific hybridization events due to secondary contacts, adding complexity to the nowadays situation.