title: Phylogeny of Gracilariaceae (Rhodophyta): evidence from plastid and mitochondrial nucleotide sequences.
abstract: Gracilariaceae are mostly pantropical red algae and include ~230 species in seven genera. Infrafamilial classification of the group has long been based on reproductive characters, but previous phylogenies have shown that traditionally circumscribed groups are not monophyletic. We performed phylogenetic analyses using two plastid (universal plastid amplicon and rbcL) and one mitochondrial (cox1) loci from a greatly expanded number of taxa to better assess generic relationships and understand patterns of character distributions. Our analyses produce the most well-supported phylogeny of the family to date, and indicate that key characteristics of spermatangia and cystocarp type do not delineate genera as commonly suggested. Our results further indicate that Hydropuntia is not monophyletic. Given their morphological overlap with closely related members of Gracilaria, we propose that Hydropuntia be synonymized with the former. Our results additionally expand the known ranges of several Gracilariaceae species to include Brazil. Lastly, we demonstrate that the recently described Gracilaria yoneshigueana should be synonymized as G. domingensis based on morphological and molecular characters. These results demonstrate the utility of DNA barcoding for understanding poorly known and fragmentary materials of cryptic red algae.
authors.affiliation: Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s/n, Feira de Santana, Bahia, 44031-460, Brazil.
authors.forename: Goia de M
authors.initials: Gde M
authors.lastname: Lyra
authors.affiliation: Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo, 05508-900, Brazil.
authors.forename: Emmanuelle da S
authors.initials: Eda S
authors.lastname: Costa
authors.affiliation: Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s/n, Feira de Santana, Bahia, 44031-460, Brazil.
authors.forename: Priscila B
authors.initials: PB
authors.lastname: de Jesus
authors.affiliation: Laboratório de Algas Marinhas, Instituto de Biologia, Universidade Federal da Bahia, Rua Barão de Jeremoabo, s/n, Salvador, Bahia, 40.170-115, Brazil.
authors.forename: João Carlos G
authors.initials: JC
authors.lastname: de Matos
authors.affiliation: Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s/n, Feira de Santana, Bahia, 44031-460, Brazil.
authors.forename: Taiara A
authors.initials: TA
authors.lastname: Caires
authors.affiliation: Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo, 05508-900, Brazil.
authors.forename: Mariana C
authors.initials: MC
authors.lastname: Oliveira
authors.affiliation: Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo, 05508-900, Brazil.
authors.forename: Eurico C
authors.initials: EC
authors.lastname: Oliveira
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University Herbaria, 22 Divinity Avenue, Cambridge, Massachusetts, 02138, USA.
authors.forename: Zhenxiang
authors.initials: Z
authors.lastname: Xi
authors.affiliation: Laboratório de Algas Marinhas, Instituto de Biologia, Universidade Federal da Bahia, Rua Barão de Jeremoabo, s/n, Salvador, Bahia, 40.170-115, Brazil.
authors.forename: José Marcos de C
authors.initials: JM
authors.lastname: Nunes
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University Herbaria, 22 Divinity Avenue, Cambridge, Massachusetts, 02138, USA.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Davis
keywords: Gracilaria; Gracilariopsis; Hydropuntia; systematics; taxonomy