Australian Laurencia majuscula (Rhodophyta, Rhodomelaceae) and the Brazilian Laurencia dendroidea are conspecific

Abstract

Summary Morphological and molecular studies have been undertaken on two species of the red algal genus Laurencia J.V.Lamouroux: Laurencia majuscula (Harvey) A.H.S. Lucas and Laurencia dendroidea J.Agardh, both from their type localities. The phylogenetic position of these species was inferred by analysis of the chloroplast‐encoded rbcL gene sequences from 24 taxa. In all phylogenetic analyses, the Australian Laurencia majuscula and the Brazilian L. dendroidea formed a well‐supported monophyletic clade within the Laurencia sensu stricto. This clade was divided into two subclades corresponding to each geographical region; however, the genetic divergence between Australian L. majuscula and Brazilian L. dendroidea was only 0–1.35%. Examination of the type specimens and sequences of freshly collected samples of both Laurencia majuscula and L. dendroidea show the two to be conspecific despite their disjunct type localities.

A new molecular phylogeny of the Laurencia complex (Rhodophyta, Rhodomelaceae) and a review of key morphological characters result in a new genus, Coronaphycus, and a description of C. novus

“…Distances need to be considered in light of other evidence but can be useful indicators of closeness of relationships between taxa. In rbcL analyses of the Laurencia complex, distances of around 10% are high enough to be considered separate genera, distances between 2% and 8% are considered to be within the one genus, and taxa with distances of less than 2% are generally accepted as being within the same species (D ıaz-Larrea et al 2007, Martin-Lescanne et al 2010, Metti et al 2013.…”

“…The rbcL gene and the rbcL-rbcS spacer region were amplified in one independent PCR for most samples. Primers used were FrbcL_start_sh and RrbcS_start (Freshwater and Rueness 1994), or YF_1 and YR_rbcS (Metti et al 2013). Those that were not amplified in one piece were amplified in two pieces using FrbcL_start_sh and YR_921 (CGA GAA TAA GTT GAA TTA CCT GC), plus F939 and RrbcS_start (Freshwater and Rueness 1994).…”

“…Four lL of purified PCR product was run on an agarose gel to visualize DNA concentrations. Primers used for sequencing reactions were the same as for DNA amplification, as well as F749 (Metti et al 2013), R749 (modified during this study from an original primer outlined in Freshwater and Rueness 1994) and R1150 (Freshwater and Rueness 1994). The sequencing mixture was made to 20 lL, with the following concentration of reagents: 12 lL of dH 2 O, 2 lL of 59 buffer, 2 lL of Big Dye terminator, 2 lL of a single 1.6 lM primer, and 2 lL of purified PCR product.…”

“…Trees were rooted using the outgroup method. Chondria, a closely related genus to the Laurencia complex, was used as the outgroup (Metti et al 2013). Phylogenetic analyses were run for the rbcL gene using maximum-parsimony (MP), maximum-likelihood (ML), and Bayesian inference (BI) algorithms.…”

Laurencia majuscula var. elegans (Rhodophyta, Rhodomelaceae) is reinstated to specific rank as L. elegans

“…This move was based on a general comparison between habits using South Australian material, with a comment that L. elegans shows characteristics of L. majuscula but without percurrent axes and with less prominent epidermal cell projection. Recently it was proposed that L. majuscula and L. dendroidea J. Agardh () are conspecific, with L. dendroidea being the earlier name (Metti et al ). However, the variety L. majuscula var.…”