DNA barcoding reveals high diversity in the Gelidiales of the Brazilian southeast coast

Abstract

Morphological identification of species in the order Gelidiales can be difficult and controversial because of phenotypic plasticity, the low numbers of reproductive specimens and poorly defined taxonomic boundaries. A DNA barcoding survey of Brazilian specimens of Gelidiales, employing neighbor-joining and Automatic Barcode Gap Discovery analyses, indicated the presence of 23 statistically robust primary species hypotheses (PSH). In addition to the cytochrome oxidase I gene (COI-5P), the chloroplast universal plastid amplicon (UPA) marker was also sequenced and submitted to the same analyses. Representatives of each COI-5P/UPA PSH were selected for rbcL sequence analysis to further corroborate the occurrence of 23 species and to infer their phylogenetic relationships. These analyses confirmed the identity of six species previously cited for Brazil: Gelidiella acerosa, G. ligulata, Gelidium crinale, G. floridanum, Pterocladiella bartlettii and P. capillacea. Three new reports for Brazil were also detected: Gelidium microdonticum, Pterocladiella beachiae and P. australafricanensis. Fourteen species remain unidentified and require detailed morphological evaluation.

Molecular Assisted Identification Reveals Hidden Red Algae Diversity from the Burica Peninsula, Pacific Panama

“…Thomas and Freshwater [48] suggested based on rbcL sequence divergences and slight morphological differences, that there was a genetic dicontinuity between specimens they identified as G. floridanum from Caribbean Costa Rica and G. floridanum in the Western Atlantic. Recent species delimination analyses with both UPA and COI-5P data distinguished G. floridanum from a closely related sister species that included the Caribbean Costa Rica G. 'floridanum' [18], and this separation was also present in the analyses here ( Figure 8). Gelidium sclerophyllum and G. floridanum are considered to represent geminate sister species with a transisthmian distribution [31].…”

“…Saunders [11] and Robba et al [12] introduced the five prime end of the mitochondrial marker cytochrome c oxidase subunit 1 (COI-5P) for DNA barcoding in red algae and many subsequent studies have demonstrated its utility for species delimitation and identification e.g., [13][14][15]. Domain V of the plastid-encoded large ribosomal subunit gene, which is also referred to as the Universal Plastid Amplicon (UPA) and the RuBisCO large subunit gene (rbcL), specifically the 3 end of this locus (rbcL-3P) are other DNA sequences that have been used to delimit and identify red macroalgae e.g., [16][17][18].…”

Pterocladiella maribagoensis (Gelidiales, Rhodophyta), a new marine alga from Cebu, Philippines

“…Shimada et al 2000, Freshwater et al 2010, Sohrabipour et al 2013, Iha et al 2015, Boo et al 2016b). Pterocladiella maribagoensis is morphologically similar to P. phangiae, however, P. phangiae has a corymbose habit with lateral branches arising at right angles to main axis, and tetrasporangial sori with sterile margin (Sohrabipour et al 2013).…”

“…To identify our specimens by molecular markers, we analyzed mitochondrial cox1 and plastid rbcL sequences that are commonly used in the taxonomy of the Gelidiales (e.g. Freshwater et al 1995, Freshwater et al 2010, Boo et al 2010, 2016a, b, Sohrabipour et al 2013, Iha et al 2015. On the basis of morphological observations and phylogenetic analyses of two genetic markers, we concluded that our specimens in Philippines represent a new species of gelidioid red algae, which we describe as Pterocladiella maribagoensis sp.…”

Taxonomic reappraisal of Gelidium coarctatum (Gelidiales, Rhodophyta) and Gelidium lineare sp. nov. from the tropical western Atlantic

“…Rico et al 2002;Kim et al 2012;Sohrabipour et al 2013;Boo et al 2016). Iha et al (2015) generated DNA sequence data from specimens identified as 'Gelidium sp. 5' that subsequent morphological analyses revealed were G. coarctatum sensu Ugadim.…”