Filogenómica de las especies de Deschampsia (Poaceae) del Cono Sur de Sudamérica.
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Date
2024
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Publisher
Universidad de Concepción
Abstract
El género Deschampsia P. Beauv es un linaje de gramíneas que se encuentra en regiones frías y templadas de todos los continentes. Comprende al menos 50 especies, de las cuales 15 se encuentran en Sudamérica, particularmente en el sur de los Andes de Chile y Argentina, considerado un importante centro de diversidad ya que corresponde al 30% de las especies del género. Las diferencias en la delimitación de Deschampsia se deben a su similitud morfológica.
Este estudio tiene como objetivo inferir las relaciones filogenéticas de las especies dentro del género Deschampsia en el Cono sur de Sudamérica.
Esta investigación se realizó utilizando muestras de herbario de la Universidad de Concepción (CONC) y del Herbario Nacional de Paris (P). Estudiamos un total de 30 muestras, que corresponden a 22 especies, las cuales representan el 44% del total de especies del género, y un 86,67% de las especies del Cono Sur. Se planteó la hipótesis de que las especies endémicas de Deschampsia de la región del Cono Sur formarían un grupo monofilético. Utilizamos la técnica Target Sequencing y el set de sondas Angiosperm353, que permite secuenciar 353 genes previamente identificados con un alto valor filogenético informativo en Angiospermas. La herramienta de análisis genómico obtuvo una taza de éxito del 83.3%, incluyendo muestras antiguas, una de ellas de más de 100 años. Realizamos una reconstrucción filogenética bayesiana para inferir las relaciones evolutivas entre especies. Nuestros resultados muestran un árbol de consenso bien resuelto con altas probabilidades posteriores en los nodos, contrariamente a nuestras expectativas, las especies de Deschampsia presentes en la región no constituyen un grupo monofilético. El clado con mayor número de especies del Cono Sur incluye D. elegantula, D. setacea, D. patula, D. cordillerarum, D. danthonioides y D. pulchra. Sin embargo, otras especies se situaron en clados diferentes. Nuestros resultados sugieren la influencia de factores históricos y geográficos en la diversificación del género en esta región, lo que abre nuevas vías de investigación sobre los procesos evolutivos y dispersión a larga distancia como factores claves en la evolución del género.
The genus Deschampsia P. Beauv is a lineage of grasses found in cold and temperate regions of all continents. It comprises at least 50 species, of which 15 are found in South America, particularly in the southern Andes of Chile and Argentina, where it is considered an important center of diversity, accounting for 30% of the species in the genus. Differences in the delimitation of Deschampsia are due to their morphological similarity. This study aims to infer the phylogenetic relationships of species within the genus Deschampsia in the Southern Cone of South America. This research was carried out using herbarium specimens from the University of Concepción (CONC) and the National Herbarium of Paris (P). We studied a total of 30 samples, corresponding to 22 species, which represent 44% of the total number of species of the genus, and 86.67% of the species of the Southern Cone. We hypothesised that the endemic Deschampsia species of the Southern Cone region would form a monophyletic group. We used the Target Sequencing technique and the Angiosperm353 probe set, which allows the sequencing of 353 previously identified genes with a high phylogenetic informative value in Angiosperms. The genomic analysis tool obtained a success rate of 83.3%, including old samples, one of them more than 100 years old. We performed a Bayesian phylogenetic reconstruction to infer evolutionary relationships between species. Our results show a well-resolved consensus tree with high posterior probabilities at the nodes. Contrary to our expectations, the Deschampsia species present in the region do not constitute a monophyletic group. The clade with the highest number of species from the Southern Cone includes D. elegantula, D. setacea, D. patula, D. cordillerarum, D. danthonioides and D. pulchra. However, other species were placed in different clades. Our results suggest the influence of historical and geographical factors on the diversification of the genus in this region, which opens new avenues of research on evolutionary processes and long-distance dispersal as key factors in the evolution of the genus.
The genus Deschampsia P. Beauv is a lineage of grasses found in cold and temperate regions of all continents. It comprises at least 50 species, of which 15 are found in South America, particularly in the southern Andes of Chile and Argentina, where it is considered an important center of diversity, accounting for 30% of the species in the genus. Differences in the delimitation of Deschampsia are due to their morphological similarity. This study aims to infer the phylogenetic relationships of species within the genus Deschampsia in the Southern Cone of South America. This research was carried out using herbarium specimens from the University of Concepción (CONC) and the National Herbarium of Paris (P). We studied a total of 30 samples, corresponding to 22 species, which represent 44% of the total number of species of the genus, and 86.67% of the species of the Southern Cone. We hypothesised that the endemic Deschampsia species of the Southern Cone region would form a monophyletic group. We used the Target Sequencing technique and the Angiosperm353 probe set, which allows the sequencing of 353 previously identified genes with a high phylogenetic informative value in Angiosperms. The genomic analysis tool obtained a success rate of 83.3%, including old samples, one of them more than 100 years old. We performed a Bayesian phylogenetic reconstruction to infer evolutionary relationships between species. Our results show a well-resolved consensus tree with high posterior probabilities at the nodes. Contrary to our expectations, the Deschampsia species present in the region do not constitute a monophyletic group. The clade with the highest number of species from the Southern Cone includes D. elegantula, D. setacea, D. patula, D. cordillerarum, D. danthonioides and D. pulchra. However, other species were placed in different clades. Our results suggest the influence of historical and geographical factors on the diversification of the genus in this region, which opens new avenues of research on evolutionary processes and long-distance dispersal as key factors in the evolution of the genus.
Description
Tesis presentada para optar al optar al título de Bióloga
Keywords
Biogeografía, Filogenia, América del Sur