Molecular genetic identification of crustose representatives of the order Corallinales (Rhodophyta) in Chile.
Knowledge on species of the order Corallinales along the coast of Chile is still scarce despite a number of studies and records of other divisions of seaweeds made since the early 20th century. This lack of information is more dramatic among crustose representatives of the order, thus depriving biogeographic studies of a thorough analysis and resulting in inadequately representative accounts of biodiversity. The currently changing taxonomy of the group makes it difficult to identify and differentiate among taxa based on morphological and developmental characters. Therefore, the use of molecular tools has been adopted in this study in order to facilitate identification and comparison of crustose corallines collected at the rocky intertidal between 27 degrees and 48 degrees S along the Pacific temperate coast of South America. A sequence 600bp (in length) from the SSU-rDNA gene was used to identify five taxa to the genus level: Lithophyllum, Spongites, Mesophyllum, Synarthrophyton, and Leptophytum. In all cases, the genus distinction based on morphological characters coincide with designations based on variation in the ribosomal DNA gene sequence. Spongites is the most frequently occurring genus and is found in all localities sampled while the others appear occasionally. Taxa recognition at species level must be examined with caution considering that morphological variability is not well understood in Chile because the SSU-rDNA region sequence does not always stand alone as an unambiguous means of identifying all coralline species. In such cases, more rapidly evolving markers are needed. For example, sequences from the ITS (rDNA) region often provide greater resolution among closely related species and genera. However, the methodology presented here remains a useful tool for species-level identification.
Vidal
Rodrigo
R
Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago, Chile.
Meneses
Isabel
I
Smith
Macarena
M
D000818:Animals; D037421:Anthozoa / Q000235:genetics*; D001483:Base Sequence; D002677:Chile; D016000:Cluster Analysis; D017931:DNA Primers; D004275:DNA, Ribosomal / Q000235:genetics; D030561:Databases, Nucleic Acid; D014644:Genetic Variation; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010140:Pacific Ocean; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity
D017931:DNA Primers; D004275:DNA, Ribosomal