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1.
Am J Bot ; 110(11): e16249, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37792319

RESUMO

PREMISE: Bryophytes form a major component of terrestrial plant biomass, structuring ecological communities in all biomes. Our understanding of the evolutionary history of hornworts, liverworts, and mosses has been significantly reshaped by inferences from molecular data, which have highlighted extensive homoplasy in various traits and repeated bursts of diversification. However, the timing of key events in the phylogeny, patterns, and processes of diversification across bryophytes remain unclear. METHODS: Using the GoFlag probe set, we sequenced 405 exons representing 228 nuclear genes for 531 species from 52 of the 54 orders of bryophytes. We inferred the species phylogeny from gene tree analyses using concatenated and coalescence approaches, assessed gene conflict, and estimated the timing of divergences based on 29 fossil calibrations. RESULTS: The phylogeny resolves many relationships across the bryophytes, enabling us to resurrect five liverwort orders and recognize three more and propose 10 new orders of mosses. Most orders originated in the Jurassic and diversified in the Cretaceous or later. The phylogenomic data also highlight topological conflict in parts of the tree, suggesting complex processes of diversification that cannot be adequately captured in a single gene-tree topology. CONCLUSIONS: We sampled hundreds of loci across a broad phylogenetic spectrum spanning at least 450 Ma of evolution; these data resolved many of the critical nodes of the diversification of bryophytes. The data also highlight the need to explore the mechanisms underlying the phylogenetic ambiguity at specific nodes. The phylogenomic data provide an expandable framework toward reconstructing a comprehensive phylogeny of this important group of plants.


Assuntos
Briófitas , Hepatófitas , Filogenia , Briófitas/genética , Plantas/genética , Hepatófitas/genética
2.
Acta amaz ; 48(4): 330-337, Oct.-Dec. 2018. graf, tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1455375

RESUMO

Piper bellidifolium, Piper durilignum, Piper acutilimbum and Piper consanguineum are bushes that occur in the Amazon and are morphologically similar. With the aim of analyzing the chemical profile of the volatile constituents of these species, essential oils from the leaves were obtained through steam distillation and analyzed using gas chromatography-flame ionization detection (GC-FID) and gas chromatograph coupled to a mass spectrometer (GC-MS). The chemical analysis enabled the identification of 95 compounds representing 96.3 ± 0.6% of the P. bellidifolium oil, 95.5 ± 0.71% of the P. durilignum oil, 98.0 ± 1.0% of the P. acutilimbum oil and 96.1 ± 2.1% of the P. consanguineum oil. Although sesquiterpenes were the predominant chemical class in the oils of the four species, qualitative and quantitative differences were found in their chemical composition. The major constituents were (E)-nerolidol (20.3 ± 0.4%) in the P. bellidifolium oil, germacrene D (11.1 ± 0.3%) in the P. durilignum oil, and -eudesmol in both the P. consanguineum (18.6 ± 0.5%) and P. acutilimbum (7.5 ± 0.4%) oils. Despite their morphological similarity, a principal component analysis (PCA) of the GC-MS data clearly separated the four species according to the chemical profile of the essential oil extracted from their leaves.


Piper bellidifolium, Piper durilignum, Piper acutilimbum e Piper consanguineum são arbustos que ocorrem na Amazônia e são morfologicamente similares. Com o intuito de analisar o perfil químico dos constituintes voláteis dessas espécies, óleos essenciais das folhas foram obtidos por hidrodestilação e analisados por cromatografia gasosa - detector por ionização de chama (CG-FID) e cromatografia gasosa acoplada a espectrometria de massa (CG-EM). A análise química permitiu identificar 95 compostos, representando 96.3 ± 0.6% do óleo de P. bellidifolium; 95.5 ± 0.71% de P. durilignum; 98.0 ± 1.0% de P. acutilimbum e 96.1 ± 2.1% de P. consanguineum. Apesar dos óleos das quatro espécies terem sesquiterpeno como classe química predominante, diferenças qualitativas e quantitativas em sua composição química foram observadas. Os principais componentes encontrados foram: (E)-nerolidol (20.3 ± 0.4%) em P. bellidifolium; germacreno D (11.1 ± 0.3%) em P. durilignum; e -eudesmol nos óleos de P. consanguineum (18.6 ± 0.5%) e P. acutilimbum (7.5 ± 0.4%). Apesar da similaridade morfológica entre as espécies, uma análise de componentes principais (PCA) dos dados de CG-EM claramente separou as quatro espécies quanto ao perfil químico do óleo essencial extríado de suas folhas.


Assuntos
Extratos Vegetais/química , Piper/química , Óleos Voláteis/análise , Óleos Voláteis/química , Brasil , Ecossistema Amazônico
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