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Background and Aims: The grass genus Urochloa (Brachiaria) sensu lato includes forage crops that are important for beef and dairy industries in tropical and sub-tropical Africa, South America and Oceania/Australia. Economically important species include U. brizantha, U. decumbens, U. humidicola, U. mutica, U. arrecta, U. trichopus, U. mosambicensis and Megathyrsus maximus, all native to the African continent. Perennial growth habits, large, fast growing palatable leaves, intra- and interspecific morphological variability, apomictic reproductive systems and frequent polyploidy are widely shared within the genus. The combination of these traits probably favoured the selection for forage domestication and weediness, but trait emergence across Urochloa cannot be modelled, as a robust phylogenetic assessment of the genus has not been conducted. We aim to produce a phylogeny for Urochloa that includes all important forage species, and identify their closest wild relatives (crop wild relatives). Finally, we will use our phylogeny and available trait data to infer the ancestral states of important forage traits across Urochloa s.l. and model the evolution of forage syndromes across the genus., Methods: Using a target enrichment sequencing approach (Angiosperm 353), we inferred a species-level phylogeny for Urochloa s.l., encompassing 54 species (~40 % of the genus) and outgroups. Phylogenies were inferred using a multispecies coalescent model and maximum likelihood method. We determined the phylogenetic placement of agriculturally important species and identified their closest wild relatives, or crop wild relatives, based on well-supported monophyly. Further, we mapped key traits associated with Urochloa forage crops to the species tree and estimated ancestral states for forage traits along branch lengths for continuous traits and at ancestral nodes in discrete traits., Key Results: Agricultural species belong to five independent clades, including U. brizantha and U. decumbens lying in a previously defined species complex. Crop wild relatives were identified for these clades supporting previous sub-generic groupings in Urochloa based on morphology. Using ancestral trait estimation models, we find that five morphological traits that correlate with forage potential (perennial growth habits, culm height, leaf size, a winged rachis and large seeds) independently evolved in forage clades., Conclusions: Urochloa s.l. is a highly diverse genus that contains numerous species with agricultural potential, including crop wild relatives that are currently underexploited. All forage species and their crop wild relatives naturally occur on the African continent and their conservation across their native distributions is essential. Genomic and phenotypic diversity in forage clade species and their wild relatives need to be better assessed both to develop conservation strategies and to exploit the diversity in the genus for improved sustainability in Urochloa cultivar production., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company.)

Background and Aims: Diploid and polyploid Urochloa (including Brachiaria, Panicum and Megathyrsus species) C4 tropical forage grasses originating from Africa are important for food security and the environment, often being planted in marginal lands worldwide. We aimed to characterize the nature of their genomes, the repetitive DNA and the genome composition of polyploids, leading to a model of the evolutionary pathways within the group including many apomictic species., Methods: Some 362 forage grass accessions from international germplasm collections were studied, and ploidy was determined using an optimized flow cytometry method. Whole-genome survey sequencing and molecular cytogenetic analysis were used to identify chromosomes and genomes in Urochloa accessions belonging to the 'brizantha' and 'humidicola' agamic complexes and U. maxima., Key Results: Genome structures are complex and variable, with multiple ploidies and genome compositions within the species, and no clear geographical patterns. Sequence analysis of nine diploid and polyploid accessions enabled identification of abundant genome-specific repetitive DNA motifs. In situ hybridization with a combination of repetitive DNA and genomic DNA probes identified evolutionary divergence and allowed us to discriminate the different genomes present in polyploids., Conclusions: We suggest a new coherent nomenclature for the genomes present. We develop a model of evolution at the whole-genome level in diploid and polyploid accessions showing processes of grass evolution. We support the retention of narrow species concepts for Urochloa brizantha, U. decumbens and U. ruziziensis, and do not consider diploids and polyploids of single species as cytotypes. The results and model will be valuable in making rational choices of parents for new hybrids, assist in use of the germplasm for breeding and selection of Urochloa with improved sustainability and agronomic potential, and assist in measuring and conserving biodiversity in grasslands., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Annals of Botany Company.)

Context: Excessive production of growth hormone causes marked multiorgan changes in patients with acromegaly, which may involve epigenetic mechanisms., Objective: To evaluate differences in circulating microRNAs (miRNAs) associated with chronic growth hormone overproduction in adults., Design and Setting: A cross-sectional case-control study was conducted at a tertiary medical center., Participants: We enrolled 12 consecutive patients with acromegaly along with 12 age- and sex-matched controls in the discovery phase of the study and then extended this cohort to 47 patients with acromegaly and 28 healthy controls for the validation study., Main Outcome Measures: Plasma miRNAs were quantified by next-generation sequencing (NGS) in the discovery phase. Levels of selected miRNAs were validated on extended cohorts using reverse transcription quantitative polymerase chain reaction (RT-qPCR), compared between groups, and correlated with clinical parameters., Results: Based on NGS data, we selected 3 plasma miRNAs downregulated in patients with acromegaly compared to healthy controls: miR-4446-3p -1.317 (P = 0.001), miR-215-5p -3.040 (P = 0.005), and miR-342-5p -1.875 (P = 0.013) without multiplicity correction for all 3 miRNAs. These results were confirmed by RT-qPCR in the validation phase for 2 miRNAs out of 3: miR-4446-3p (P < 0.001, Padjusted < 0.001), area under the receiver-operator curve (AUC) 0.862 (95% CI 0.723-0.936; P < 0.001) and miR-215-5p (P < 0.001, Padjusted < 0.001), AUC 0.829 (95% CI 0.698-0.907; P < 0.001) to differentiate patients with acromegaly from healthy controls., Conclusions: In a 2-phase experiment using 2 different techniques we found and validated the downregulation of plasma miR-4446-3p and miR-215-5p in patients with acromegaly compared to healthy subjects, which makes them promising biomarkers for further research., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

C$&#95;{4}$ photosynthesis is a complex trait that sustains fast growth and high productivity in tropical and subtropical conditions and evolved repeatedly in flowering plants. One of the major C$&#95;{4}$ lineages is Andropogoneae, a group of $\sim $1200 grass species that includes some of the world's most important crops and species dominating tropical and some temperate grasslands. Previous efforts to understand C$&#95;{4}$ evolution in the group have compared a few model C$&#95;{4}$ plants to distantly related C$&#95;{3}$ species so that changes directly responsible for the transition to C$&#95;{4}$ could not be distinguished from those that preceded or followed it. In this study, we analyze the genomes of 66 grass species, capturing the earliest diversification within Andropogoneae as well as their C$&#95;{3}$ relatives. Phylogenomics combined with molecular dating and analyses of protein evolution show that many changes linked to the evolution of C$&#95;{4}$ photosynthesis in Andropogoneae happened in the Early Miocene, between 21 and 18 Ma, after the split from its C$&#95;{3}$ sister lineage, and before the diversification of the group. This initial burst of changes was followed by an extended period of modifications to leaf anatomy and biochemistry during the diversification of Andropogoneae, so that a single C$&#95;{4}$ origin gave birth to a diversity of C$&#95;{4}$ phenotypes during 18 million years of speciation events and migration across geographic and ecological spaces. Our comprehensive approach and broad sampling of the diversity in the group reveals that one key transition can lead to a plethora of phenotypes following sustained adaptation of the ancestral state. [Adaptive evolution; complex traits; herbarium genomics; Jansenelleae; leaf anatomy; Poaceae; phylogenomics.]., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society of Systematic Biologists.)

Background and Aims: Recent developments in DNA sequencing, so-called next-generation sequencing (NGS) methods, can help the study of rare lineages that are known from museum specimens. Here, the taxonomy and evolution of the Malagasy grass lineage Chasechloa was investigated with the aid of NGS., Methods: Full chloroplast genome data and some nuclear sequences were produced by NGS from old herbarium specimens, while some selected markers were generated from recently collected Malagasy grasses. In addition, a scanning electron microscopy analysis of the upper floret and cross-sections of the rachilla appendages followed by staining with Sudan IV were performed on Chasechloa to examine the morphology of the upper floret and the presence of oils in the appendages., Key Results: Chasechloa was recovered within tribe Paniceae, sub-tribe Boivinellinae, contrary to its previous placement as a member of the New World genus Echinolaena (tribe Paspaleae). Chasechloa originated in Madagascar between the Upper Miocene and the Pliocene. It comprises two species, one of them collected only once in 1851. The genus is restricted to north-western seasonally dry deciduous forests. The appendages at the base of the upper floret of Chasechloa have been confirmed as elaiosomes, an evolutionary adaptation for myrmecochory., Conclusions: Chasechloa is reinstated at the generic level and a taxonomic treatment is presented, including conservation assessments of its species. Our study also highlights the power of NGS technology to analyse relictual or probably extinct groups., (© The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background and Aims: Earth's climate is dynamic, with strong glacial-interglacial cycles through the Late Quaternary. These climate changes have had major consequences for the distributions of species through time, and may have produced historical legacies in modern ecological patterns. Unstable regions are expected to contain few endemic species, many species with strong dispersal abilities, and to be susceptible to the establishment of exotic species from relatively stable regions. We test these hypotheses with a global dataset of grass species distributions., Methods: We described global patterns of endemism, variation in the potential for rapid population spread, and exotic establishment in grasses. We then examined relationships of these response variables to a suite of predictor variables describing the mean, seasonality and spatial pattern of current climate and the temperature change velocity from the Last Glacial Maximum to the present., Key Results: Grass endemism is strongly concentrated in regions with historically stable climates. It also depends on the spatial pattern of current climate, with many endemic species in areas with regionally unusual climates. There was no association between the proportion of annual species (representing potential population spread rates) and climate change velocity. Rather, the proportion of annual species depended very strongly on current temperature. Among relatively stable regions (<10 m year -1 ), increasing velocity decreased the proportion of species that were exotic, but this pattern reversed for higher-velocity regions (>10 m year -1 ). Exotic species were most likely to originate from relatively stable regions with climates similar to those found in their exotic range., Conclusions: Long-term climate stability has important influences on global endemism patterns, largely confirming previous work from other groups. Less well recognized is its role in generating patterns of exotic species establishment. This result provides an important historical context for the conjecture that climate change in the near future may promote species invasions., (© The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Collections of specimens held by natural history museums are invaluable material for biodiversity inventory and evolutionary studies, with specimens accumulated over 300 years readily available for sampling. Unfortunately, most museum specimens yield low-quality DNA. Recent advances in sequencing technologies, so called next-generation sequencing, are revolutionizing phylogenetic investigations at a deep level. Here, the Illumina technology (HiSeq) was used on herbarium specimens of Sartidia (subfamily Aristidoideae, Poaceae), a small African-Malagasy grass lineage (six species) characteristic of wooded savannas, which is the C3 sister group of Stipagrostis, an important C4 genus from Africa and SW Asia. Complete chloroplast and nuclear ribosomal sequences were assembled for two Sartidia species, one of which (S. perrieri) is only known from a single specimen collected in Madagascar 100 years ago. Partial sequences of a few single-copy genes encoding phosphoenolpyruvate carboxylases (ppc) and malic enzymes (nadpme) were also assembled. Based on these data, the phylogenetic position of Malagasy Sartidia in the subfamily Aristidoideae was investigated and the biogeographical history of this genus was analysed with full species sampling. The evolutionary history of two genes for C4 photosynthesis (ppc-aL1b and nadpme-IV) in the group was also investigated. The gene encoding the C4 phosphoenolpyruvate caroxylase of Stipagrostis is absent from S. dewinteri suggesting that it is not essential in C3 members of the group, which might have favoured its recruitment into a new metabolic pathway. Altogether, the inclusion of historical museum specimens in phylogenomic analyses of biodiversity opens new avenues for evolutionary studies., (© The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background and Aims: An accurate characterization of biodiversity requires analyses of DNA sequences in addition to classical morphological descriptions. New methods based on high-throughput sequencing may allow investigation of specimens with a large set of genetic markers to infer their evolutionary history. In the grass family, the phylogenetic position of the monotypic genus Lecomtella, a rare bamboo-like endemic from Madagascar, has never been appropriately evaluated. Until now its taxonomic treatment has remained controversial, indicating the need for re-evaluation based on a combination of molecular and morphological data., Methods: The phylogenetic position of Lecomtella in Poaceae was evaluated based on sequences from the nuclear and plastid genomes generated by next-generation sequencing (NGS). In addition, a detailed morphological description of L. madagascariensis was produced, and its distribution and habit were investigated in order to assess its conservation status., Key Results: The complete plastid sequence, a ribosomal DNA unit and fragments of low-copy nuclear genes (phyB and ppc) were obtained. All phylogenetic analyses place Lecomtella as an isolated member of the core panicoids, which last shared a common ancestor with other species >20 million years ago. Although Lecomtella exhibits morphological characters typical of Panicoideae, an unusual combination of traits supports its treatment as a separate group., Conclusions: The study showed that NGS can be used to generate abundant phylogenetic information rapidly, opening new avenues for grass phylogenetics. These data clearly showed that Lecomtella forms an isolated lineage, which, in combination with its morphological peculiarities, justifies its treatment as a separate tribe: Lecomtelleae. New descriptions of the tribe, genus and species are presented with a typification, a distribution map and an IUCN conservation assessment.

In a series of dawn-to-dusk studies, we examined the nature and accessibility of nectar rewards for pollinating insects by monitoring insect visits and the secretion rate and standing crop of nectar in the British native plant species Salvia pratensis , Stachys palustris , S. officinalis , Lythrum salicaria , Linaria vulgaris , the non-native Calendula officinalis , Petunia  ×  hybrida , Salvia splendens , and the possibly introduced Saponaria officinalis . We also compared single with double variants of Lotus corniculatus , Saponaria officinalis , Petunia  ×  hybrida and Calendula officinalis . All the British species studied are nectar-rich and are recommended for pollinator-friendly gardens. They showed maximal secretion rates of about 10-90 μg sugar per flower h -1 , and most had mean standing crops of about 5-60 μg sugar per flower. In all British species studied, the corolla was deep enough for the relatively long-tongued bumblebee Bombus pascuorum , but the shallower flowers of Lythrum salicaria were also much visited by shorter-tongued bees and hoverflies, as well as by butterflies. The exotic Salvia splendens , presumably coevolved with hummingbirds in the Neotropics, has such deep flowers that British bees cannot reach the nectar except by crawling down the corolla. With a secretion rate approaching 300 μg sugar per flower h -1 and little depletion by insects, S. splendens accumulated high standing crops of nectar. S. splendens , and single and double flowers of the two probably moth-pollinated species Petunia  ×  hybrida and Saponaria officinalis , received few daytime visits despite abundant nectar but Calendula was well visited by hoverflies and bees. We compared single and double variants of Lotus corniculatus , Petunia  ×  hybrida and Calendula officinalis , and also Saponaria officinalis , the last being probably introduced in Britain (Stace, 1997 New flora of the British Isles. 2nd edn. Cambridge: Cambridge University Press). In Petunia , Saponaria and Lotus , double flowers secreted little or no nectar. In Calendula , where doubling involved a change in the proportion of disc and ray florets rather than modification of individual flower structure, double and single capitula had similar standing crops of nectar. Except in Calendula , exotic or double flowers were little exploited by insect visitors. In the exotics, this was probably due to the absence or scarcity of coevolved pollinators, coupled, in double flowers, with the absence of nectar., (Copyright 2001 Annals of Botany Company.)