Sistemática molecular del complejo Laurencia (Ceramiales, Rhodophyta) en el Caribe mexicano
In the current work the species from the Laurencia complex of the Mexican Caribbean were molecular characterized. Furthermore, the work deals with phylogeny of Laurencia complex and taking into account these phylogenetics relationships, some taxonomic opinions were expressed. To carry out the alread...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2008 |
| Country: | México |
| Institution: | Universidad Autónoma Metropolitana |
| Repository: | Repositorio Institucional de la UAM Iztapalapa |
| Language: | Spanish |
| OAI Identifier: | oai:bindani.izt.uam.mx:2r36tx81n |
| Online Access: | https://doi.org/10.24275/uami.2r36tx81n |
| Access Level: | Open access |
| Keyword: | info:eu-repo/classification/LEM/Algas marinas -- Caribe (Región) info:eu-repo/classification/LEM/Marine Algae -- Caribe info:eu-repo/classification/LEM/Algas rojas -- México -- Identificación info:eu-repo/classification/LEM/Red Algae -- Mexico -- Identification info:eu-repo/classification/cti/3 |
| Summary: | In the current work the species from the Laurencia complex of the Mexican Caribbean were molecular characterized. Furthermore, the work deals with phylogeny of Laurencia complex and taking into account these phylogenetics relationships, some taxonomic opinions were expressed. To carry out the already mentioned purposes, fresh samples were collected in nine localities through five-hundred kilometers around in the Caribbean coast of the Yucatán peninsula. A total of forty-one samples that includes nine species previously cited as well as the non-identified material were submitted to molecular treatment. The genetic divergence values obtained allow to split the taxonomic categories in specific levels. The highest genetic divergence values were obtained for RUBISCO spacer followed by rbcL. The codon usage for taxa included in grupo externo, Laurencia, Palisada and Osmundea was similar, because of this the mentioned method not allow the groups distinction. The secondary structure comparison allow the clades distinction that corresponding to Palisada and Laurencia genera. The phylogenetics hypothesis based on rbcL, RUBISCO spacer and 18S sequences comparisons corroborated that Laurencia sensu lato is monophyletic and includes three distinct monophyletic clades corresponding to the genera Palisada, Laurencia sensu stricto and Osmundea. Because of this the author conclude that the three genera are distinct units and they don’t correspond to a complex assemblage. The combination of two or more genes in the phylogenetics analyses improve the support of the proposed phylogenetics hypothesis. The analyses with twenty-one coincident taxa to the three genes results in 18S better support and stables topologies. Molecular characters allow to improve the classification scheme of Laurencia sensu lato in intrageneric level. The following taxonomic proposals were made in the current work: two new records for the study zone, Palisada perforata and Osmundea sp; two new combinations, Palisada poiteaui var. gemmifera (Harvey) Sentíes, Fujii et Díaz and Palisada corallopsis (Montagne) Sentíes, Fujii et Díaz; the conspecificity of P. papillosa y P. perforata. The genetic divergence values suggests the existence of a possible new specie in Laurencia genus. In that sense, in the present work we recognize nine taxa for the Mexican Caribbean: five for the Laurencia genus (L. caraibica, L. intricata, L. venusta, L. cf. filiformis and L. sp.), one for Osmundea (O. sp) and four of Palisada genus (P. corallopsis, P. poiteaui var gemmifera, P. poiteaui var poiteaui and P. perforata). |
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