RESUMEN
Abstract The Ibitipoca Mountains occur in southeastern Minas Gerais state, Southeast Brazil, and includes a mosaic of different vegetation types, as part of the Atlantic Forest domain. Such heterogeneity results in the occurrence of several ecotones in the region, considered essential buffer zones for maintaining biodiversity and structure among adjacent ecosystems. Given the importance of these environments for biodiversity conservation, floristic surveys are important to catalogue plant richness in natural areas, where species and landscapes have been destroyed, especially over the last decades. To contribute to increase the knowledge on the vascular Flora in the Ibitipoca Mountains, a floristic inventory was undertaken in private properties located in the boundaries of "Parque Estadual do Ibitipoca" (Ibitipoca State Park). Relevant findings of the present study include: characterization of the different vegetation types, 17 new records for the Flora of Minas Gerais, collection of 288 species never recorded in the state park (80% dissimilarity - especially due to the occurrence and size of different phytophysiognomies between these areas) and presence of 31 threatened species. In addition, discussions about conservation efforts and public policies are presented.
Resumo A Serra do Ibitipoca ocorre no sudeste do estado de Minas Gerais, sudeste do Brasil, e inclui um mosaico de diferentes tipos de vegetação, como parte do domínio da Mata Atlântica. Tal heterogeneidade é resultado da ocorrência de diversos ecótonos na região, considerados áreas de amortecimento essenciais para manutenção da biodiversidade e estrutura de ecossistemas adjacentes. Dada a importância destes ambientes para conservação da biodiversidade, inventários florísticos são importantes para catalogar a riqueza de plantas em áreas naturais, onde espécies e paisagens têm sido destruídas, especialmente nas últimas décadas. Para contribuir com o aumento do conhecimento sobre a Flora vascular na Serra do Ibitipoca, um inventário florístico foi conduzido em áreas privadas adjacentes ao Parque Estadual do Ibitipoca. As descobertas mais relevantes do presente estudo incluem: caracterização dos diferentes tipos de vegetação, 17 novos registros para a Flora de Minas Gerais, coleta de 288 espécies nunca registradas para o parque (80% de dissimilaridade - especialmente devido à ocorrência e tamanho de diferentes fitofisionomias entre as áreas) e presença de 31 espécies ameaçadas. Além disso, discussões sobre esforços para conservação e políticas públicas são apresentadas.
RESUMEN
Phylogenomic data from a rapidly increasing number of studies provide new evidence for resolving relationships in recently radiated clades, but they also pose new challenges for inferring evolutionary histories. Most existing methods for reconstructing phylogenetic hypotheses rely solely on algorithms that only consider incomplete lineage sorting (ILS) as a cause of intra- or intergenomic discordance. Here, we utilize a variety of methods, including those to infer phylogenetic networks, to account for both ILS and introgression as a cause for nuclear and cytoplasmic-nuclear discordance using phylogenomic data from the recently radiated flowering plant genus Polemonium (Polemoniaceae), an ecologically diverse genus in Western North America with known and suspected gene flow between species. We find evidence for widespread discordance among nuclear loci that can be explained by both ILS and reticulate evolution in the evolutionary history of Polemonium. Furthermore, the histories of organellar genomes show strong discordance with the inferred species tree from the nuclear genome. Discordance between the nuclear and plastid genome is not completely explained by ILS, and only one case of discordance is explained by detected introgression events. Our results suggest that multiple processes have been involved in the evolutionary history of Polemonium and that the plastid genome does not accurately reflect species relationships. We discuss several potential causes for this cytoplasmic-nuclear discordance, which emerging evidence suggests is more widespread across the Tree of Life than previously thought. [Cyto-nuclear discordance, genomic discordance, phylogenetic networks, plastid capture, Polemoniaceae, Polemonium, reticulations.].
Asunto(s)
Genoma de Plastidios , Magnoliopsida , Flujo Génico , Genoma de Plastidios/genética , Filogenia , Plastidios/genéticaRESUMEN
The pantropical genus Rourea Aubl. (Connaraceae) is composed of ca. 70 species, most of which occur in the Neotropics. Rourea is currently subdivided into three subgenera, with the American taxa included in Rourea subgen. Rourea. Forero (1976) recognised six sections for the species of the New World, with Rourea subgen. R. sect. Multifoliolatae being exclusive to Brazil, characterised by multifoliolate leaves, relatively small leaflets and the staminal tube (0.8-)1-1.5 mm long. Following Forero's (1976) treatment, additional botanical collections have become available in Brazilian herbaria, allowing re-evaluation of species concepts. This work recognises and revises 12 species in this section, mainly restricted to southeastern Brazil and southern Bahia. A nomenclatural and taxonomic study of these species is here presented, including an identification key, morphological descriptions, illustrations and geographic distribution maps. A new species is also described.