Cycads are the only gymnosperms forming a symbiosis with nitrogen-fixing cyanobacteria in a specialized organ: the coralloid root. This paper investigates the endophytic bacterial community ...inhabiting the coralloid roots of two cycads from Panama. We sampled coralloid roots from
Zamia nana
(terrestrial) and
Zamia pseudoparasitica
(epiphytic). Then, we used the 16S rRNA amplicon marker to describe the entire bacterial community. We also designed a new marker to amplify the
rbc
L-
rbc
X spacer and around 100 bp of the
rbc
X gene, targeting cyanobacteria. We found that using 16S, endophytic bacteria diversity is represented mainly by the phyla Actinobacteria, Cyanobacteria, and Proteobacteria. In addition, 16S analyses showed that
Zamia
species do not share a core cyanobacterial community (using stringent 75% and 90% thresholds), while the two species shared 4 ASVs at a 50% threshold. The newly developed
rbc
L-
rbc
X marker revealed that both species share a core cyanobacterial community represented by a single amplicon sequence variant (ASV1) (
Nostoc sp.
) at 90% threshold that is found in the same phylogenetic clade of that contain mostly Panamanian symbiotic cyanobacteria. Using a 75% threshold, only three ASVs (ASV1, ASV2, ASV3) were present across samples, and five ASVs at 50% threshold. This new marker can effectively identify cyanobacteria ASVs and provide a better resolution for microbial analyses in autotroph cyanobacterial symbioses.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Plant-microbe interactions play a pivotal role in shaping host fitness, especially concerning chemical defense mechanisms. In cycads, establishing direct correlations between specific endophytic ...microbes and the synthesis of highly toxic defensive phytochemicals has been challenging. Our research delves into the intricate relationship between plant-microbe associations and the variation of secondary metabolite production in two closely related Zamia species that grow in distinct habitats; terrestrial and epiphytic. Employing an integrated approach, we combined microbial metabarcoding, which characterize the leaf endophytic bacterial and fungal communities, with untargeted metabolomics to test if the relative abundances of specific microbial taxa in these two Zamia species were associated with different metabolome profiles. The two species studied shared approximately 90% of the metabolites spanning diverse biosynthetic pathways: alkaloids, amino acids, carbohydrates, fatty acids, polyketides, shikimates, phenylpropanoids, and terpenoids. Co-occurrence networks revealed positive associations among metabolites from different pathways, underscoring the complexity of their interactions. Our integrated analysis demonstrated to some degree that the intraspecific variation in metabolome profiles of the two host species was associated with the abundance of bacterial orders Acidobacteriales and Frankiales, as well as the fungal endophytes belonging to the orders Chaetothyriales, Glomerellales, Heliotiales, Hypocreales, and Sordariales. We further associate individual metabolic similarity with four specific fungal endophyte members of the core microbiota, but no specific bacterial taxa associations were identified. This study represents a pioneering investigation to characterize leaf endophytes and their association with metabolomes in tropical gymnosperms, laying the groundwork for deeper inquiries into this complex domain.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Understanding the mechanisms underlying species assembly is a central focus of plant ecology and is crucial to revealing how plant communities are structured. However, the temporal limitations of ...most terrestrial plant communities preclude collection of species assembly data in a tractable time‐frame.
The aim of this study is to investigate the importance of dispersal potential, as estimated by interspecific variation in sexual and asexual expression, as a predictor of patch chronosequence assembly for epiphyllous (leaf‐inhabiting) bryophytes. Secondarily, we investigate whether spatiotemporal patterns in patch turnover and compositional variation infer evidence of local (within‐patch) population processes. The frequency and distribution of 55 epiphyllous bryophytes across five leaf age classes were studied on an understorey shrub Piper grande (Piperaceae) in premontane Panamanian tropical forest. Logistical models were used to test whether interspecific variation in dispersal‐related life‐history traits predicts assembly order. Beta diversity and ordination analyses were employed to examine nestedness vs. turnover, and probe for repeatable patterns in patch chronosequence assembly, respectively.
Our results emphasize the importance of dispersal potential on species assembly patterns as earlier arrivals exhibit greater probabilities of sexual and specialized asexual expression. High turnover coupled with temporal convergence in species composition also points to evidence of within‐patch biotic filtering.
Synthesis. Epiphylls are locally diverse in humid tropical forests worldwide; however, the mechanisms which maintain their high local diversity are unknown. This study suggests that interspecific variation in dispersal capacity in combination with diffuse indirect effects is the principal contributor to the high alpha‐diversity of these ephemeral metacommunities.
RESUMEN
Un aspecto importante en la ecología de plantas es la comprensión de los mecanismos que actúan en el ensamblaje de las especies, lo que es crucial para revelar cómo se estructuran las comunidades. Sin embargo, las limitaciones temporales de la mayoría de las comunidades de plantas imposibilita la recolección de datos en un marco de tiempo adecuado.
El objetivo de este estudio es investigar la importancia del potencial de dispersión estimada por la variación inter‐específica en la expresión sexual y asexual para predecir la secuencia cronológica del ensamblaje de especies de briofitas epífilas (habitan sobre hojas). En segundo lugar, investigamos si los patrones espacio‐temporales del recambio y la variación en la composición de las especies corresponden a procesos locales poblacionales. Se estudió la frecuencia y distribución de 55 briofitas epífilas en cinco posiciones de las hojas a lo largo de una secuencia cronológica en el arbusto de sotobosque Piper grande (Piperaceae) en un bosque tropical premontano panameño. Se utlizaron modelos logísticos para probar si las variaciones inter‐específicas relacionadas con la dispersión en el ciclo de vida de las plantas podría predecir el orden en el ensamblaje de las especies. Se ulilizaron análisis de diversidad beta y de ordenación para examinar la anidación versus el recambio y buscar patrones repetitivos de ensamblaje a lo largo de una secuencia cronológica.
Nuestros resultados enfatizan la importancia del potencial de dispersión para predecir los patrones de ensamblaje de las especies donde los primeros colonizadores muestran altas tasas en su expresión sexual y especialización asexual. El alto recambio junto con la convergencia temporal en la composición de las especies también apunta a la evidencia de filtros bióticos en el micrositio de la hoja.
Síntesis. A nivel local, existe una gran riqueza de especies epífilas en los bosques tropicales húmedos del mundo; sin embargo, se desconocen los mecanismos que mantienen esta alta diversidad. Este estudio sugiere que las variaciones inter‐específicas en la capacidad de dispersión combinadas con efectos indirectos difusos contribuyen principalmente con la alta diversidad‐alfa de estas metacomunidades efímeras.
Epiphylls are locally diverse in humid tropical forests worldwide; however, the mechanisms which maintain their high local diversity are unknown. This study suggests that interspecific variation in dispersal capacity in combination with diffuse indirect effects is the principal contributor to the high alpha‐diversity of these ephemeral metacommunities.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Drepanolejeunea robinsonii C.E.Zartman & A.M.Sierra is described and illustrated herein as a new species from the Amazon basin. The type collections are from lowland rainforest habitat in the central ...Amazon of Brazil. Morphological characters which distinguish the new species from the phenotypically similar Drepanolejeunea polyrhiza (Nees) Grolle & R.L.Zhu, are: 1) ovate leaf form; 2) conspicuously acute leaf apices; and 3) irregularly dentate to serrate teeth composed of 2–5 cells on leaf margins. Androecia were repeatedly observed on separate gametophytes suggesting the new taxon is dioecious, however neither gynoecia nor perianths have yet to be observed.
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We describe four new species in the genus
(i.e.,
.
,
.
, and
.
) from Brazil, all presently classified in subg.
. For each of the new taxa we discuss taxonomic affinities and provide information on ...habitat, distribution, and conservation status. In addition, line drawings and scanning electron microscope (SEM) images of stems sections, leaves, and spores (when present) are included.
and
are from the State of Espíritu Santo where they inhabit premontane to montane Atlantic rain forests in the Reserva Biológica Augusto Ruschi and Parque Estadual Forno Grande, respectively.
was collected in upper montane forests at Parque Nacional Serra da Mocidade, State of Roraima and
in premontane Amazon rain forests on upper Rio Negro at Mpio. São Gabriel da Cachoeira, Amazonas State in both Serra Curicuriari and the Morro dos Seis Lagos Biological Reserve.
ABSTRACT Campinaranas are unique vegetation patches in the Amazonian biome, characterized by white-sand soils with relatively low nutrient content and subject to periodic flooding coupled with ...fluctuating groundwater levels. This study aimed to produce a synopsis of the bryophyte flora in Campinarana habitats by combining information from the literature with new collections made in the Uatumã Sustainable Development Reserve (Balbina, Central Amazonia), and areas of the middle Uaupés river (São Gabriel da Cachoeira, upper Rio Negro). One hundred and forty-three species were identified among mosses and liverworts, of which 68 are reported for the first time in Campinaranas. The species Frullania rio-janeirensis, Ceratolejeunea filaria, Diplasiolejeunea cobrensis and Bazzania diversicuspis are new records for the state of Amazonas. These results reveal high species richness for Campinaranas and indicate the need for continued study in this underexplored Amazonian habitat. This study emphasizes the importance of carrying out floristic inventories in poorly known environments and of further studies with different approaches, such as ecological, phytogeographic and genetic efforts.
Abstract Results from recent botanical excursions in northern Brazil include 38 new state and country records. In summary, seven (five liverworts and two mosses) taxa are newly confirmed for Brazil, ...18 (10 liverworts and eight mosses) new to Amazonas state and 20 (16 liverworts and four mosses) new to Roraima state.
Resumo Excursões botânicas recentes no norte do Brasil resultaram em 38 registros novos para estados brasileiros e o país. Resumido, sete (cinco hepáticas e dois musgos) espécies são novos registros para o Brasil, 18 sendo novos registros para o estado do Amazonas (10 hepáticas e oito musgos) e 20 para o estado de Roraima (16 hepáticas e quatro musgos).
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In the past decade, floristic studies have rebounded as checklists are fundamental for executing meta-analyses which address ecological, biogeographic and evolutionary questions of broad geographic ...scope. Despite the importance of checklists as baseline records of local diversity and distributions, few attempts have been made to quantify sampling effort and species detectability within and among study sites. Quantitative floristics, which combines the use of checklists with statistical methods for estimating local richness, is a promising method for characterizing the completeness of checklists especially for cryptic components of biodiversity. For bryophytes, quantifying levels of detectability among substrate types is of central importance, especially in tropical forests where much of their diversity is harbored in difficult to access habitats such as the tree canopy. In light of the need to establish quantifiable protocols of detectability in poorly studied tropical regions, we present a bryophyte checklist for the Jaú National Park (JNP), located in the heart of the Amazon, and estimate local species richness and detectability as it relates to five substrate types (epiphytes, epiphylls, epixylic, epipetric and soil). Identifications from 712 collections made during four excursions over the past decade to JNP revealed 150 species consisting of two new country records and five new state records, along with 20 rarely collected Amazonian endemics. Despite our intensive sampling, which included systematic canopy collections during one of the excursions, Chao richness index estimated that ca. 46 species (nearly one-third of those presently observed) remain undetected from JNP. Furthermore, levels of detectability among substrates varied widely, where observed epiphyte richness, in contrast to the other substrates types, most closely approximated the estimates. Our results illustrate the need for quantitative richness estimates as a means to increase the accuracy of checklist data, particularly when used in meta-analyses addressing global-scale questions.
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ABSTRACT Pycnolejeunea is a pantropical genus represented in Brazil by nine species, according to the present treatment. Pycnolejeunea chocoensis M.E. Reiner & Gradst., recently described for ...Colombia, is being cited for the first time for Brazil. Descriptions are given for all species and illustrations only for Pycnolejeunea chocoensis, Pycnolejeunea contigua (Nees) Grolle, Pycnolejeunea papillosa X.-L. He and Pycnolejeunea porrectilobula C.J. Bastos & O. Yano. A key to the species of Pycnolejeunea occurring in Brazil is also presented.
RESUMO Pycnolejeunea é um gênero pantropical e está representado no Brasil por nove espécies, de acordo com o presente tratamento. Pycnolejeunea chocoensis M.E. Reiner & Gradst., descrita recentemente para Colômbia, está sendo citada pela primeira vez para o Brasil. Descrições são apresentadas para todas as espécies e ilustração apenas para Pycnolejeunea contigua (Nees) Grolle, Pycnolejeunea chocoensis, Pyconolejeunea papillosa X.-L. He e Pycnolejeunea porrectilobula C.J. Bastos & O. Yano. Uma chave para identificação das espécies de Pycnolejeunea que ocorrem no Brasil é também apresentada.
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