Hybrid capture of 964 nuclear genes resolves evolutionary relationships in the mimosoid legumes and reveals the polytomous origins of a large pantropical radiation

PREMISE Targeted enrichment methods facilitate sequencing of hundreds of nuclear loci to enhance phylogenetic resolution and elucidate why some parts of the “tree of life” are difficult (if not impossible) to resolve. The mimosoid legumes are a prominent pantropical clade of ~3300 species of woody angiosperms for which previous phylogenies have shown extensive lack of resolution, especially among the species‐rich and taxonomically challenging ingoids. METHODS We generated transcriptomes to select low‐copy nuclear genes, enrich these via hybrid capture for representative species of most mimosoid genera, and analyze the resulting data using de novo assembly and various phylogenomic tools for species tree inference. We also evaluate gene tree support and conflict for key internodes and use phylogenetic network analysis to investigate phylogenetic signal across the ingoids. RESULTS Our selection of 964 nuclear genes greatly improves phylogenetic resolution across the mimosoid phylogeny and shows that the ingoid clade can be resolved into several well‐supported clades. However, nearly all loci show lack of phylogenetic signal for some of the deeper internodes within the ingoids. CONCLUSIONS Lack of resolution in the ingoid clade is most likely the result of hyperfast diversification, potentially causing a hard polytomy of six or seven lineages. The gene set for targeted sequencing presented here offers great potential to further enhance the phylogeny of mimosoids and the wider Caesalpinioideae with denser taxon sampling, to provide a framework for taxonomic reclassification, and to study the ingoid radiation

Evidência de hibridação e introgressão em Hybanthus arenarius Ule e H. calceolaria (L.) Oken (Violaceae) a partir de marcadores aloenzimáticos e análise multivariada morfométrica

Allozyme and multivariate morphometric analyses using 46 morphological characters were carried out in 41 individuals of Hybanthus arenarius, 25 individuals of H. calceolaria and 33 morphologically intermediate individuals occurring on the campus of the Universidade Estadual de Feira de Santana to quantify the variability within these populations and to test hypotheses of hybridization and introgression. H. arenarius could be well differentiated in the morphometric analysis from both intermediate and H. calceolaria individuals, but the latter two groups could not be separated. Those same relationships were found in the allozyme analysis. The lack of diagnostic loci does not allow definitive confirmation of natural hybridization between the two species. However, several results found in the morphometric and genetic analyses reinforce the hypothesis that the individuals considered formerly as intermediate are actually individuals of H. calceolaria introgressed from H. arenarius.Foram realizadas análise morfométrica multivariada baseada em 46 caracteres morfológicos e análise de aloenzimas em 41 indivíduos de Hybanthus arenarius, 25 indivíduos de H. calceolaria e 33 indivíduos morfologicamente intermediários ocorrentes no campus da Universidade Estadual de Feira de Santana para determinar a variabilidade nestas populações e investigar hipóteses de hibridação e introgressão. Na análise morfométrica, H. arenarius pode ser bem diferenciada dos indivíduos intermediários e H. calceolaria, enquanto estes dois últimos não podem ser bem separados. Estas mesmas relações foram aparentes também na análise de aloenzimas. A ausência de loci diagnósticos não permite a confirmação de hibridação entre as espécies, mas vários resultados encontrados nas análises morfométrica e genética fortalecem a hipótese de que os indivíduos considerados primariamente como intermediários sejam indivíduos de H. calceolaria com introgressão de genes de H. arenarius

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora