Sinopsis global y aproximación a la filogenia molecular del género Parablechnum C. Presl (Blechnaceae, Polypodiopsida)A global synopsis and molecular phylogenetic approach of the genus Parablechnum C.Presl (Blechnaceae, Polypodiopsida)

Resumo

The family Blechnaceae is a lineage that includes about 280 species in 25 genera, and together with the Onocleaceae is the most recent family of ferns. Within this family, Parablechnum is the most diverse genus, with about 65 species. The distribution of this genus reflects very well the distribution of the most diverse areas of the family: Central and South America, the Austropacific and some representatives in southern Africa, Madagascar and the Mascarene archipelago.The distribution of this genus reflects a disjunction that could easily be explained by Gondwanan vicariance, but the available dating indicates that the genus underwent a rapid radiation after the separation from Gondwana, which would imply that its distribution is due to long-distance dispersal (LDD). In addition, the intra-continental dispersal of the genus together with other problems such as poor representation in herbaria has made the taxonomy of Parablechnum unclear to date.In this context, a revision of the systematics of the genus has been proposed using herbarium material and some field collections to elucidate the taxonomy and evolutionary history of the genus.For this purpose, 3,738 specimens from 52 herbariums of all the species of Parablechnum conceived to date have been examined physically and digitally. Where possible, the anatomy of the fertile pinnae and epidermis was studied, and spores and sporangia were observed by light and electron microscopy. In addition, DNA was extracted from 127 individuals and five chloroplastic markers were sequenced for maximum likelihood phylogenetic trees and Bayesian inference. In addition, a dating have been carried out. For this purpose, 582 sequences were used, 469 of which were newly created in this work...