MOLECULAR TAXONOMY AND PHYLOGENOMICS OF CERAMIALES (RHODOPHYTA) HIGHLIGHT CHALLENGES AND ADVANCES IN UNDERSTANDING THE DIVERSITY AND SYSTEMATICS OF ALGAL TURFS

Díaz-Tapia, Pilar

Abstract

Algal turfs are ecosystem engineers receiving growing attention in relation to their expansion on temperate reefs as a consequence of global change. However, their species diversity and taxonomy are still poorly understood. Turfs are composed of densely entangled small seaweeds, in which the red algal order Ceramiales is commonly a major component. The advent of classical molecular taxonomy and -omic approaches has revolutionized investigations of seaweed diversity and systematics. These approaches have been applied to the study of the Ceramiales, facilitating the discovery of new species and resolving classification issues. A molecular diversity survey using the rbcL gene and involving the study of ca. 400 specimens of turf-forming rhodomelacean species in Macaronesia detected impressive amounts of newly discovered diversity. A total of 67 species were identified, of which half corresponded to undescribed species presumably endemic to this bioregion. Likewise, the application of molecular species delimitation methods to widely distributed records of Polysiphonia scopulorum (>150 samples collected in Australia, South Africa, southern Europe and Macaronesia) revealed that it is a complex in which 13 species were resolved. These 13 cryptic species range from endemics with narrow known distributions to a species found in all studied regions. At taxonomic levels above species, the use of plastid phylogenomics has produced well-resolved phylogenies that have been applied to the resolution of classification issues in the Ceramiales. These studies illustrate how classical and newer evolving molecular techniques facilitate the understanding of seaweed diversity and systematics, and provide new insights into the complexity of turf assemblages.

MOLECULAR TAXONOMY AND PHYLOGENOMICS OF CERAMIALES (RHODOPHYTA) HIGHLIGHT CHALLENGES AND ADVANCES IN UNDERSTANDING THE DIVERSITY AND SYSTEMATICS OF ALGAL TURFS

Author: Díaz-Tapia, Pilar

Source: https://digital.csic.es/bitstream/10261/316677/4/IPC_Abstract_Diaz-Tapia.pdf

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SYM09: A u u e o algal axonomy: challenges and p ospec s
Keyno e lec u e
MOLECULAR TAXONOMY AND PHYLOGENOMICS OF CERAMIALES (RHODOPHYTA)
HIGHLIGHT CHALLENGES AND ADVANCES IN UNDERSTANDING THE DIVERSITY
AND SYSTEMATICS OF ALGAL TURFS
Pila Diaz-Tapia1,2
(1) Ins i u o Español de Oceanog a ía, Cen o Oceanog á ico A Co uña, Paseo Ma í imo Alcalde
F ancisco Vázquez, 10, 15001, A Co uña, Spain
(2) Uni e sidade da Co uña, BioCos Resesea ch G oup, Facul ade de Ciencias, Campus da Zapa ei a,
s/n, 15008, A Co uña, Spain
Algal u s a e ecosys em enginee s ecei ing g owing a en ion in ela ion o hei expansion on empe a e
ee s as a consequence o global change. Howe e , hei species di e si y and axonomy a e s ill poo ly
unde s ood. Tu s a e composed o densely en angled small seaweeds, in which he ed algal o de
Ce amiales is commonly a majo componen . The ad en o classical molecula axonomy and -omic
app oaches has e olu ionized in es iga ions o seaweed di e si y and sys ema ics. These app oaches
ha e been applied o he s udy o he Ce amiales, acili a ing he disco e y o new species and esol ing
classi ica ion issues. A molecula di e si y su ey using he bcL gene and in ol ing he s udy o ca. 400
specimens o u - o ming hodomelacean species in Maca onesia de ec ed imp essi e amoun s o newly
disco e ed di e si y. A o al o 67 species we e iden i ied, o which hal co esponded o undesc ibed
species p esumably endemic o his bio egion. Likewise, he applica ion o molecula species delimi a ion
me hods o widely dis ibu ed eco ds o Polysiphonia scopulo um (>150 samples collec ed in Aus alia,
Sou h A ica, sou he n Eu ope and Maca onesia) e ealed ha i is a complex in which 13 species we e
esol ed. These 13 c yp ic species ange om endemics wi h na ow known dis ibu ions o a species
ound in all s udied egions. A axonomic le els abo e species, he use o plas id phylogenomics has
p oduced well- esol ed phylogenies ha ha e been applied o he esolu ion o classi ica ion issues in
he Ce amiales. These s udies illus a e how classical and newe e ol ing molecula echniques acili a e
he unde s anding o seaweed di e si y and sys ema ics, and p o ide new insigh s in o he complexi y
o u assemblages.
Financing: PDT acknowledges suppo by GAIN, Xun a de Galicia, Spain (g an s 03-IN858A-2019-1630129
and ED481D/2017/011)
Keywo ds: Classi ica ion, High Th oughpu Sequencing, molecula species delimi a ion