Person: Luceño Garcés, Modesto
Catedrático/a de Universidad
Universidad Pablo de Olavide
Biología Molecular e Ingeniería Bioquímica
Sistemática y Evolución Vegetal
Biología y Biotecnología, Recursos Naturales, Energía y Medio Ambiente
Now showing 1 - 6 of 6
PublicationSelection by climatic regime and neutral evolutionary processes in holocentric chromosomes (Carex gr. laevigata: Cyperaceae): A microevolutionary approach(Elsevier, 2013-03-07) Escudero, Marcial; Maguilla Salado, Enrique; Luceño Garcés, ModestoThe holocentric structure promotes chromosome rearrangements by fission, fusion, translocation, and inversion, which have been thought to promote differentiation and speciation. The Carex laevigata group (Cyperaceae) comprises four species: two restricted endemics from the western Mediterranean (Carex camposii, 2n = 72, and Carex paulo-vargasii, 2n = 74–75), and two more widespread species, found mostly in Western Europe (C. laevigata, 2n = 69–84, and Carex binervis, 2n = 72–74). We tested the selection for chromosome number by climatic variables by controlling for the non-independence of the data using generalized linear mixed model (GLMM). We obtained chromosome counts as well as DNA sequences for the 5 trnK intron and the trnV-ndhC intergenic spacer in the chloroplast genome from 181 individuals from 53 populations representing these four species. We also climatically characterized the sites where the 53 populations were found using the WorldClim database. Our results show that the best predictor of chromosome number variation is the climatic environment rather than neutral evolutionary processes like founder events and migration patterns. These results support the adaptive value of the holocentric chromosomes and their role in promoting differentiation and eventually speciation. PublicationPhylogeny, systematics, and trait evolution of Carex section Glareosae(Wiley, 2015-05-20) Maguilla Salado, Enrique; Escudero, Marcial; Waterway, Marcia J.; Hipp, Andrew L.; Luceño Garcés, ModestoThe circumboreal Carex section Glareosae comprises 20–25 currently accepted species. High variability in geographic distribution, ecology, cytogenetics, and morphology has led to historical problems both in species delimitation and in circumscribing the limits of the section, which is one of the major tasks facing caricologists today. We performed phylogenetic reconstructions based on ETS, ITS, G3PDH, and m at K DNA sequences from 204 samples. Concatenation of gene regions in a supermatrix approach to phylogenetic reconstruction was compared to coalescent-based species-tree estimation. Ancestral state reconstructions were performed for eight morphological characters to evaluate correspondence between phylogeny and traits used in traditional classifi cation within the section. The results confi rm the existence of a core Glareosae comprising 23–25 species. Most species constitute exclusive lineages, and relationships among species are highly resolved with both the supermatrix and coalescent-based species-tree approaches. We used ancestral state reconstruction to investigate sources of homoplasy underlying traditional taxonomy and species circumscription. We found that even species apparently not constituting exclusive lineages are morphologically homogeneous, raising the question of whether paraphyly of species is a phylogenetic artifact in our study or evidence of widespread homoplasy in characters used to defi ne species. This study demonstrates the monophyly of C arex section G lareosae and establishes a phylogenetic framework for the section. Homoplasy makes many of morphological characters diffi cult to apply for taxon delimitation. The strong concordance between supermatrix and species-tree approaches to phylogenetic reconstructions suggests that even in the face of incongruence among molecular markers, section-level or species-level phylogenies in Carex are tractable. PublicationGenome size stability despite high chromosome number variation in Carex gr. laevigata(Wiley, 2015-02-02) Escudero, Marcial; Maguilla Salado, Enrique; Loureiro, João; Castro, Mariana; Castro, Silvia; Luceño Garcés, ModestoIn organisms with holocentric chromosomes like Carex species, chromosome number evolution has been hypothesized to be a result of fission, fusion, and/or translocation events. Negative, positive, or the absence of correlations have been found between chromosome number and genome size in Carex. Using the inferred diploid chromosome number and 80 genome size measurements from 26 individuals and 20 populations of Carex gr. laevigata, we tested the null hypothesis of chromosome number evolution by duplication and deletion of whole chromosomes. Our results show a significant positive correlation between genome size and chromosome number, but the slope of such correlation supports the hypothesis of proliferation and removal of repetitive DNA fragments to explain genome size variation rather than duplication and deletion of whole chromosomes. Our results refine the theory of the holokinetic drive: this mechanism is proposed to facilitate repetitive DNA removal (or any segmental deletion) when smaller homologous chromosomes are preferentially inherited, or repetitive DNA proliferation (or any segmental duplication) when larger homologs are preferred. This study sheds light on how karyotype evolution plays an important role in the diversification of the species of the genus Carex. PublicationNew insights into the systematics of the Schoenoxiphium clade (Carex, Cyperaceae)(University of Chicago Press, 2017-03-27) Villaverde, Tamara; Maguilla Salado, Enrique; Escudero, Marcial; Márquez Corro, José Ignacio; Jiménez Mejías, Pedro; Gehrke, Berit; Martín Bravo, Santiago; Luceño Garcés, ModestoThe Schoenoxiphium clade (Carex, Cyperaceae) exhibits a high species diversity in South Africa and a complex taxonomy. Previous phylogenetic studies did not resolve the species relationships within the Schoenoxiphium clade due to the lack of informative characters in DNA markers used. Our aim is to resolve the species relationships within the Schoenoxiphium clade by adding information from more markers and more samples to information from previous studies. We sampled 19 out of 20 recognized species in the former genus Schoenoxiphium. Four DNA regions (two nuclear ribosomal: internal transcribed spacer, external transcribed spacer; two plastid: matK and rps16) were sequenced for 134 samples. Phylogenetic reconstruction was performed using Bayesian inference and maximum likelihood analyses. The monophyly of the Schoenoxiphium clade was confirmed. Five main clades with strong support were retrieved in congruence with a previous phylogeny. Although species relationships within these clades are still partially unresolved, our phylogeny highlights the need for the description of at least two new species in this group. The monophyly of the former genus Schoenoxiphium, taken together with its morphological synapomorphies and the recent phylogenetic studies and subsequent recircumscription of the genus Carex to include all nested genera, advises the consideration of this clade as a section (Carex sect. Schoenoxiphium Baillon). Additional investigations based on genomic sequencing are needed to fully resolve the species relationships within each of the five main clades. PublicationVicariance versus dispersal across Beringian land bridges to explain circumpolar distribution: A case study in plants with high dispersal potential(Wiley, 2018-01-14) Maguilla Salado, Enrique; Escudero, Marcial; Luceño Garcés, ModestoThis article aims to disentangle the importance of the Beringian land bridges during the Pliocene and Quaternary periods in order to explain the current distribution of circumpolar plants with potential for long-distance dispersal. We sampled all extant species in Carex section Glareosae (26 species and 2 subspecies) and analysed 14 DNA regions, including the nrDNA regions ETS and ITS, three nuclear single-copy genes (CATP, G3PDH and GZF), and nine cpDNA regions: 50trnK intron, atpIH, matK, ndhJ-trnF, psbA-trnH, rpl32-trnL, rps16, trnC-ycf6 and ycf6-psbM. After testing for outlier proportions, we used Bayesian inference, maximum likelihood and a species-tree approach to infer phylogenetic relationships between species; divergence times were estimated using BEAST2. We then performed biogeographical analyses using “BioGeoBEARS” to estimate ancestral areas by means of reticulate models. Finally, lineage through time (LTT) and diversification pattern analyses were performed using BAMM. Our results show that Carex section Glareosae is a monophyletic group that diverged c. 6.56 Ma (4.54–8.51 Ma at 95% highest posterior density interval). We show that within-area cladogenetic speciation events and anagenetic dispersal (including some vicariance events) play an important role in shaping distribution in species with potential for long-distance dispersal. Diversification patterns show constant diversification rates over time. The Bering Strait may have played an important role in shaping the current distribution of the species in the section, facilitating dispersal between Asia and North America during glacial periods when the Beringian land bridges were open. Nevertheless, we cannot discount long-distance dispersal as an alternative major force shaping the species distribution in the section. PublicationAndreaea barbarae (Andreaeaceae, Bryophytina), a new moss species from Lesotho(Magnolia Press, 2018-01-30) Cerrejón, Carlos; Maguilla Salado, Enrique; Quandt, Dietmar; Muñoz, Jesús; Luceño Garcés, ModestoSpecimens of Andreaea sect. Andreaea collected in Lesotho show morphological differences from the remaining Sub-Saharan Africa species in the group. Particularly, Lesotho specimens have much larger spores, a character diagnostic in the genus. Spore size also separates the Lesotho specimens from typical A. rupestris from the Northern Hemisphere. Consequently, we describe a new species from the highlands of Lesotho (Andreaea barbarae). Additionally, we present a taxonomic key to all accepted species of Andreaea sect. Andreaea in sub-Saharan Africa.