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- Lagomarsino, L. P., et al.
(författare)
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Increased resolution in the face of conflict: phylogenomics of the Neotropical bellflowers (Campanulaceae: Lobelioideae), a rapid plant radiation
- 2022
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Ingår i: Annals of Botany. - : Oxford University Press (OUP). - 0305-7364 .- 1095-8290. ; 129:6, s. 723-736
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims The centropogonid clade (Lobelioideae: Campanulaceae) is an Andean-centred rapid radiation characterized by repeated convergent evolution of morphological traits, including fruit type and pollination syndromes. While previous studies have resolved relationships of lineages with fleshy fruits into subclades, relationships among capsular species remain unresolved. This lack of resolution has impeded reclassification of non-monophyletic genera, whose current taxonomy relies heavily on traits that have undergone convergent evolution. Methods Targeted sequence capture using a probe-set recently developed for the centropogonid clade was used to obtain phylogenomic data from DNA extracted from both silica-dried and herbarium leaf tissue. These data were used to infer relationships among species using concatenated and partitioned species tree methods, and to quantify gene tree discordance. Key Results While silica-dried leaf tissue resulted in longer assembled sequence data, the inclusion of herbarium samples improved taxonomic representation. Relationships among baccate lineages are similar to those inferred in previous studies, although they differ for lineages within and among capsular clades. We improve the phylogenetic resolution of Siphocampylus, which forms ten groups of closely related species which we informally name. Two subclades of Siphocampylus and two individual species are rogue taxa whose placement differs widely across analyses. Gene tree discordance (including cytonuclear discordance) is rampant. Conclusions This first phylogenomic study of the centropogonid clade considerably improves our understanding of relationships in this rapid radiation. Differences across analyses and the possibility of additional lineage discoveries still hamper a solid and stable reclassification. Rapid morphological innovation corresponds with a high degree of phylogenomic complexity, including cytonuclear discordance, nuclear gene tree conflict and well-supported differences between analyses based on different nuclear loci. Together, these results point to a potential role of hemiplasy underlying repeated convergent evolution. This hallmark of rapid radiations is probably present in many other species-rich Andean plant radiations.
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| 2. |
- Lagomarsino, L. P., et al.
(författare)
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Phylogeny, classification, and fruit evolution of the species-rich Neotropical bellflowers (Campanulaceae: Lobelioideae)
- 2014
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 101:12, s. 2097-2112
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Tidskriftsartikel (refereegranskat)abstract
- Premise of the study: The species-rich Neotropical genera Centropogon, Burmeistera, and Siphocampylus represent more than half of the similar to 1200 species in the subfamily Lobelioideae (Campanulaceae). They exhibit remarkable morphological variation in floral morphology and habit. Limited taxon sampling and phylogenetic resolution, however, obscures our understanding of relationships between and within these genera and underscores our uncertainty of the systematic value of fruit type as a major diagnostic character. Methods: We inferred a phylogeny from five plastid DNA regions (rpl32-trnL, ndhF-rpl32, rps16-trnK, trnG-trnG-trns, rbcL) using maximum-likelihood and Bayesian inference. Ancestral character reconstructions were applied to infer patterns of fruit evolution. Key results: Our results demonstrate that the majority of species in the genera Centropogon, Burmeistera, and Siphocampylus together form a primarily mainland Neotropical clade, collectively termed the "centropogonids." Caribbean Siphocampylus, however, group with other Caribbean lobelioid species. We find high support for the monophyly of Burmeistera and the polyphyly of Centropogon and mainland Siphocampylus. The ancestral fruit type of the centropogonids is a capsule; berries have evolved independently multiple times. Conclusions: Our plastid phylogeny greatly improves the phylogenetic resolution within Neotropical Lobelioideae and highlights the need for taxonomic revisions in the subfamily. Inference of ancestral character states identifies a dynamic pattern of fruit evolution within the centropogonids, emphasizing the difficulty of diagnosing broad taxonomic groups on the basis of fruit type. Finally, we identify that the centropogonids, Lysipomia, and Lobelia section Tupa form a Pan-Andean radiation with broad habitat diversity. This clade is a prime candidate for investigations of Neotropical biogeography and morphological evolution.
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| 4. |
- Uribe-Convers, S., et al.
(författare)
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Phylogenetic relationships of Burmeistera (Campanulaceae: Lobelioideae): Combining whole plastome with targeted loci data in a recent radiation
- 2017
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903. ; 107, s. 551-563
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Tidskriftsartikel (refereegranskat)abstract
- The field of molecular systematics has benefited greatly with the advent of high-throughput sequencing (HTS), making large genomic datasets commonplace. However, a large number of targeted Sanger sequences produced by many studies over the last two decades are publicly available and should not be overlooked. In this study, we elucidate the phylogenetic relationships of the plant genus Burmeistera (Campanulaceae: Lobelioideae), while investigating how to best combine targeted Sanger loci with FITS data. We sequence, annotate, and analyze complete to nearly complete plastomes for a subset of the genus. We then combine these data with a much larger taxonomic dataset for which only Sanger sequences are available, making this the most comprehensively sampled study in the genus to date. We show that using a phylogeny inferred from the species with plastome data as a topological constraint for the larger dataset increases the resolution of our data and produces a more robust evolutionary hypothesis for the group. We then use the resulting phylogeny to study the evolution of morphological traits thought to be important in Burmeistera, and assess their usefulness in the current taxonomic classification of the genus. The main morphological character used to delimit subgeneric sections, the presence or absence of hairs on the apex of the two ventral anthers, shows a complex evolutionary history with many changes in the tree, suggesting that this character should not be used for taxonomic classification. Although it is too soon to propose a new subgeneric classification for Burmeistera, our results highlight some morphological traits shared by whole clades that could potentially be used in future taxonomic work. (C) 2016 Elsevier Inc. All rights reserved.
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