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Leaf litter microbes collectively degrade plant polysaccharides, influencing land-atmosphere carbon exchange. An open question is how substrate complexity-defined as the structure of the saccharide and the amount of external processing by extracellular enzymes-influences species interactions. We tested the hypothesis that monosaccharides (i.e. xylose) promote negative interactions through resource competition, and polysaccharides (i.e. xylan) promote neutral or positive interactions through resource partitioning or synergism among extracellular enzymes. We assembled a three-species community of leaf litter-degrading bacteria isolated from a grassland site in Southern California. In the polysaccharide xylan, pairs of species stably coexisted and grew equally in coculture and in monoculture. Conversely, in the monosaccharide xylose, competitive exclusion and negative interactions prevailed. These pairwise dynamics remained consistent in a three-species community: all three species coexisted in xylan, while only two species coexisted in xylose, with one species capable of using peptone. A mathematical model showed that in xylose these dynamics could be explained by resource competition. Instead, the model could not predict the coexistence patterns in xylan, suggesting other interactions exist during biopolymer degradation. Overall, our study shows that substrate complexity influences species interactions and patterns of coexistence in a synthetic microbial community of leaf litter degraders.

Biomass allocation in plants is the foundation for understanding dynamics in ecosystem carbon balance, species competition, and plant-environment interactions. However, existing work on plant allometry has mainly focused on trees, with fewer studies having developed allometric equations for grasses. Grasses with different life histories can vary in their carbon investment by prioritizing the growth of specific organs to survive, outcompete co-occurring plants, and ensure population persistence. Further, because grasses are important fuels for wildfire, the lack of grass allocation data adds uncertainty to process-based models that relate plant physiology to wildfire dynamics. To fill this gap, we conducted a greenhouse experiment with 11 common California grasses varying in photosynthetic pathway and growth form. We measured plant sizes and harvested above- and belowground biomass throughout the life cycle of annual species, while for the establishment stage of perennial grasses to quantify allometric relationships for leaf, stem, and root biomass, as well as plant height and canopy area. We used basal diameter as a reference measure of plant size. Overall, basal diameter is the best predictor for leaf and stem biomass, height, and canopy area. Including height as another predictor can improve model accuracy in predicting leaf and stem biomass and canopy area. Fine root biomass is a function of leaf biomass alone. Species vary in their allometric relationships, with most variation occurring for plant height, canopy area, and stem biomass. We further explored potential trade-offs in biomass allocation across species between leaf and fine root, leaf and stem, and allocation to reproduction. Consistent with our expectation, we found that fast-growing plants allocated a greater fraction to reproduction. Additionally, plant height and specific leaf area negatively influenced the leaf-to-stem ratio. However, contrary to our hypothesis, there were no differences in root-to-leaf ratio between perennial and annual or C4 and C3 plants. Our study provides species-specific and functional-type-specific allometry equations for both above- and belowground organs of 11 common California grass species, enabling nondestructive biomass assessment in California grasslands. These allometric relationships and trade-offs in carbon allocation across species can improve ecosystem model predictions of grassland species interactions and environmental responses through differences in morphology.

Abstract: Hyperspectral remote sensing has the potential to map numerous attributes of the Earth’s surface, including spatial patterns of biological diversity. Grasslands are one of the largest biomes on Earth. Accurate mapping of grassland biodiversity relies on spectral discrimination of endmembers of species or plant functional types. We focused on spectral separation of grass lineages that dominate global grassy biomes: Andropogoneae (C4), Chloridoideae (C4), and Pooideae (C3). We examined leaf reflectance spectra (350–2,500 nm) from 43 grass species representing these grass lineages from four representative grassland sites in the Great Plains region of North America. We assessed the utility of leaf reflectance data for classification of grass species into three major lineages and by collection site. Classifications had very high accuracy (94%) that were robust to site differences in species and environment. We also show an information loss using multispectral sensors, that is, classification accuracy of grass lineages using spectral bands provided by current multispectral satellites is much lower (accuracy of 85.2% and 61.3% using Sentinel 2 and Landsat 8 bands, respectively). Our results suggest that hyperspectral data have an exciting potential for mapping grass functional types as informed by phylogeny. Leaf‐level hyperspectral separability of grass lineages is consistent with the potential increase in biodiversity and functional information content from the next generation of satellite‐based spectrometers.

Plants with the C4 photosynthesis pathway typically respond to climate change differently from more common C3-type plants, due to their distinct anatomical and biochemical characteristics. These different responses are expected to drive changes in global C4 and C3 vegetation distributions. However, current C4 vegetation distribution models may not predict this response as they do not capture multiple interacting factors and often lack observational constraints. Here, we used global observations of plant photosynthetic pathways, satellite remote sensing, and photosynthetic optimality theory to produce an observation-constrained global map of C4 vegetation. We find that global C4 vegetation coverage decreased from 17.7% to 17.1% of the land surface during 2001 to 2019. This was the net result of a reduction in C4 natural grass cover due to elevated CO2 favoring C3-type photosynthesis, and an increase in C4 crop cover, mainly from corn (maize) expansion. Using an emergent constraint approach, we estimated that C4 vegetation contributed 19.5% of global photosynthetic carbon assimilation, a value within the range of previous estimates (18-23%) but higher than the ensemble mean of dynamic global vegetation models (14 ± 13%; mean ± one standard deviation). Our study sheds insight on the critical and underappreciated role of C4 plants in the contemporary global carbon cycle.

Summary Grasses (Poaceae) comprise c. 11 800 species and are central to human livelihoods and terrestrial ecosystems. Knowing their relationships and evolutionary history is key to comparative research and crop breeding. Advances in genome‐scale sequencing allow for increased breadth and depth of phylogenomic analyses, making it possible to infer a new reference species tree of the family. We inferred a comprehensive species tree of grasses by combining new and published sequences for 331 nuclear genes from genome, transcriptome, target enrichment and shotgun data. Our 1153‐tip tree covers 79% of grass genera (including 21 genera sequenced for the first time) and all but two small tribes. We compared it to a newly inferred 910‐tip plastome tree. We recovered most of the tribes and subfamilies previously established, despite pervasive incongruence among nuclear gene trees. The early diversification of the PACMAD clade could represent a hard polytomy. Gene tree–species tree reconciliation suggests that reticulation events occurred repeatedly. Nuclear–plastome incongruence is rare, with very few cases of supported conflict. We provide a robust framework for the grass tree of life to support research on grass evolution, including modes of reticulation, and genetic diversity for sustainable agriculture. [ABSTRACT FROM AUTHOR]

Background: A new species of smut fungus, Urocystis heteropogonis, was discovered infecting Heteropogon contortus in Shawar Valley, Swat district, Khyber Pakhtunkhwa, Pakistan. The study aimed to characterize this fungus based on its morpho-anatomical and molecular features and clarify its phylogenetic position within the genus Urocystis. Results: Urocystis heteropogonis was identified as a novel species, distinct from other Urocystis species. Morphologically, it is characterized by larger spore balls (14–69 × 11–45 μm) and central spores that are 14–28 × 11–20 μm in size, with each spore containing1–8 central spores. The spore walls measure 0.9–2.5 μm in thickness and the species differs in infection patterns compared to other Urocystis species. Phylogenetic analysis based on the ITS and LSU regions of nuclear ribosomal DNA (nrDNA) further confirmed the novelty of the species, placing it within a distinct clade alongside U. agropyri, U. occulta, U. piptatheri, and U. tritici. Conclusions: The discovery of Urocystis heteropogonis adds to the diversity of smut fungi infecting grasses and highlights the need for further research into its ecological and agricultural implications. Future studies should focus on the disease's spread, management, and potential impact on host populations. [ABSTRACT FROM AUTHOR]

In this study, we explored the distributions of grass genera in the Southern Cone (SC) of South America, applying several phylogenetic diversity (PD) metrics and randomization tests. Grasses appear to have been present in South America since their early evolution as tropical understory species more than 60 Ma. During the course of evolution, grasses have adapted to all terrestrial biomes and become one of the most successful plant families on earth. At present, the SC contains nearly all terrestrial biomes and a wide range of humid to arid ecoregions. Analyzing 126.514 point occurrences and four plastid markers for 148 genera (91% of the native grass genera), we found that tropical humid regions hold the highest PD, with no observed bias in branch lengths. These results indicate that niche conservatism dominates the diversity pattern of grasses in the SC. We found significantly low PD in the Dry Chaco and in the Patagonian Steppe, which suggest ecological filtering in both warm and cold arid regions. The Patagonian Steppe also holds significantly longer branches than expected by chance, as the native grass flora is mainly composed of distantly related Pooideae genera with a northern hemisphere origin. Short branches are found in the Uruguayan Savanna, suggesting that these grasslands could be a cradle for grass diversity within the SC. The dated phylogeny supported the current view of a relatively recent evolution of the family within the SC, with most diversification taking place from the middle Miocene and onwards. [ABSTRACT FROM AUTHOR]

Poaceae pollen is one of the most widespread sources of aeroallergens in the world. The aim of this study is to build predictive models for the pollen season start day (PSsd) and peak dates of the Poaceae pollen season and thus give an overview of the climatic parameters that have the greatest influence. In Tétouan, sampling was carried out using a volumetric spore trap of the Burkard Hirst type. The relationships between the PSsd, peak dates and meteorological parameters were determined using correlation analysis. The models were constructed using multiple regression analysis with data from 2008 to 2019 and tested on data from 2022. The PSsd was especially significantly influenced by minimum temperature during winter and precipitation in the autumn of the previous year. The peak dates were significantly correlated with precipitation in January, March and April, but not with temperature. Three models were obtained for each of the season's parameters; the most accurate model for the PSsd explained a variability of 61% and includes as main predictors rainfall from the autumn of the previous year and the mean daily average temperature from 23 February to 8 March. The two most efficient peak dates models included precipitation in January and April as the main predictor variables, and explained greater variability (87 and 88%). Precipitation in autumn and the mean daily and the sum of minimum temperature in winter, showed significant decreasing tendencies. However, the PSsd trend delay was not statistically significant. This study draws the importance of the weather during preseason for grass pollen production and emphasises the usefulness of the models for allergic patients to take preventive measures and for healthcare professionals in allergy therapy. [ABSTRACT FROM AUTHOR]

Frost tolerance has evolved many times independently across flowering plants. However, conservation of several frost tolerance mechanisms among distant relatives suggests that apparently independent entries into freezing climates may have been facilitated by repeated modification of existing traits ('precursor traits'). One possible precursor trait for freezing tolerance is drought tolerance, because palaeoclimatic data suggest plants were exposed to drought before frost and several studies have demonstrated shared physiological and genetic responses to drought and frost stress. Here, we combine ecophysiological experiments and comparative analyses to test the hypothesis that drought tolerance acted as a precursor to frost tolerance in cool-season grasses (Pooideae). Contrary to our predictions, we measured the highest levels of frost tolerance in species with the lowest ancestral drought tolerance, indicating that the two stress responses evolved independently in different lineages. We further show that drought tolerance is more evolutionarily labile than frost tolerance. This could limit our ability to reconstruct the order in which drought and frost responses evolved relative to each other. Further research is needed to determine whether our results are unique to Pooideae or general for flowering plants. [ABSTRACT FROM AUTHOR]

Premise: Seed dispersal is a critical process impacting individual plants and their communities. Plants have evolved numerous strategies and structures to disperse their seeds, but the evolutionary drivers of this diversity remain poorly understood in most lineages. We tested the hypothesis that the evolution of wind dispersal traits within the melicgrasses (Poaceae: Meliceae Link ex Endl.) was correlated with occupation of open and disturbed habitats. Methods: To evaluate wind dispersal potential, we collected seed dispersal structures (diaspores) from 24 melicgrass species and measured falling velocity and estimated dispersal distances. Species' affinity for open and disturbed habitats were recorded using georeferenced occurrence records and land cover maps. To test whether habitat preference and dispersal traits were correlated, we used phylogenetically informed multilevel models. Results: Melicgrasses display several distinct morphologies associated with wind dispersal, suggesting likely convergence. Open habitat taxa had slower‐falling diaspores, consistent with increased wind dispersal potential. However, their shorter stature meant that dispersal distances, at a given wind speed, were not higher than those of their forest‐occupying relatives. Species with affinities for disturbed sites had slower‐falling diaspores and greater wind dispersal distances, largely explained by lighter diaspores. Conclusions: Our results are consistent with the hypothesized evolutionary relationship between habitat preference and dispersal strategy. However, phylogenetic inertia and other plant functions (e.g., water conservation) likely shaped dispersal trait evolution in melicgrasses. It remains unclear if dispersal trait changes were precipitated by or predated changing habitat preferences. Nevertheless, our study provides promising results and a framework for disentangling dispersal strategy evolution. [ABSTRACT FROM AUTHOR]

Premise: The wheat tribe, Triticeae, has been the subject of molecular phylogenetic analyses for nearly three decades, and extensive phylogenetic conflict has been apparent from the earliest comparisons among DNA‐based data sets. While most previous analyses focused primarily on nuclear vs. chloroplast DNA conflict, the present analysis provides a broader picture of conflict among nuclear loci throughout the tribe. Methods: Exon data were generated from over 1000 nuclear loci using targeted sequence capture with custom baits, and nearly complete chloroplast genome sequences were recovered. Phylogenetic conflict was assessed among the trees from the chloroplast genomes, the concatenated nuclear loci, and a series of nuclear‐locus subsets guided by Hordeum chromosome gene maps. Results: At the intergeneric level, the analyses collectively revealed a few broadly consistent relationships. However, the prevailing pattern was one of extensive phylogenetic conflict throughout the tribe, among both deep and shallow branches, and with the extent of the conflict varying among data subsets. Conclusions: The results suggest continual introgression or lineage sorting within and among the named lineages of the Triticeae, shaping both deep and shallow relationships in the tribe. [ABSTRACT FROM AUTHOR]

Hordeum pusillum (Hordeum pusillum Nutt., 1818) is an annual barley that is native to the west of the North America and widespread in southern United States and tropical America. In this study, we have provided the first complete characterization of the chloroplast genome of H. pusillum. Our research revealed that the circular chloroplast genome of H. pusillum consists of a large single-copy region (LSC: 80,853 bp), a small single-copy region (SSC: 12,745 bp), and a pair of inverted repeat regions (IRs: 21,587 bp), totaling 136,772 bp in length. Within the chloroplast genome of H. pusillum, 91 protein-coding genes, 38 tRNA genes, and ten rRNA genes were identified. To determine the evolutionary relationship of Hordeum species with reported chloroplast genome sequences, we constructed a phylogenetic tree using the entire chloroplast genome sequences. The evolutionary position of H. pusillum corresponds to its geographical location. The chloroplast genome of H. pusillum provided in this study may have significant implications for the phylogenetic study of Poaceae species. [ABSTRACT FROM AUTHOR]

Diatraea saccharalis Fabricius (Lepidoptera: Crambidae), known as sugarcane borer, is the most damaging pest of sugarcane (Saccharum officinarum L., Poaceae) in northwestern Argentina and it causes significant losses in sugar and ethanol production. Currently, chemical and biological controls are used, along with host plant resistance, but there is a clear trend toward adoption of integrated pest management strategies. Considering the potential environmental and health risks associated with using agrochemicals, our study focuses on utilizing bioactive natural products, specifically plant secondary metabolites. Senecio rudbeckiaefolius Meyen & Walp (Asteraceae) is a perennial shrub found in southern Peru, Bolivia, and northwestern Argentina, valued for its use in traditional medicine. The main compounds of the genus Senecio are sesquiterpenes, with some species containing pyrrolizidine alkaloids (PAs), known for their harmful effects on herbivorous insects and vertebrates. Plant extracts exhibit several modes of action, encompassing confusion, feeding deterrence, growth regulation, insecticidal, and repellent effects. Our goal was to analyze the chemical composition of an ethanolic extract (EE) of S. rudbeckiaefolius and evaluate its lethal and sublethal effects on D. saccharalis larvae. We also investigated the potential target sites affected by the ingestion of an alkaloidal fraction from the EE (AFEE) through a midgut histological study. The main secondary metabolites identified were the PAs and phenolic compounds, with the highest concentrations found in the flowers and leaves. The majority of the PAs identified were senecionine and integerrimine. Toxicity bioassays were carried out with larvae fed on a diet supplemented with an EE of S. rudbeckiaefolius. Concentration‐dependent mortality and a marked inhibition of larval growth were recorded. We described the midgut histological structure and compared it with that of AFEE‐fed larvae. Various morphological changes were observed in the intestinal epithelium, especially an increase in the number of goblet cells and pronounced acidophilic secretion in the lumen. These results suggest that the EE of S. rudbeckiaefolius could be promising for D. saccharalis control. [ABSTRACT FROM AUTHOR]

During our investigation of microfungi on grasslands in Yunnan Province, China, three new fungal taxa associated with grasses were collected. Morphological observations and phylogenetic analyses of the combined SSU, LSU, ITS, tef1-α, and rpb2 loci based on maximum likelihood and Bayesian inference were used to reveal the taxonomic placement of these fungal taxa. This study introduces Parastagonospora yunnanensis, Para. zhaotongensis, Phaeoseptoriella poaceicola. Parastagonospora yunnanensis is characterized by ampulliform or globose to subglobose conidiogenous cells, with conidia that are cylindrical to subcylindrical, 0–1-septate, rounded at the apex and slightly truncate at the base. Parastagonospora zhaotongensis features similar globose to subglobose conidiogenous cells but with 0–3-septate, cylindrical to subcylindrical conidia. Phaeoseptoriella poaceicola is distinguished by its globose to subglobose conidiogenous cells and phragmosporous conidia that are initially hyaline, turn pale yellowish at maturity, and are 7-septate, cylindrical to subcylindrical, either straight or slightly curved. These discoveries underscore the significance of exploring and accurately identifying fungal taxa within Ascomycota, highlighting the species richness and potential for new species discoveries in grass-based habitats. The findings from this study expand our understanding of the taxonomy and phylogeny of grassland-associated Ascomycota, providing a foundation for further ecological and taxonomic studies of these fungi within their natural environments. [ABSTRACT FROM AUTHOR]

This research is part of a Hungarian Research OTKA project that examines the vegetation of sandy grasslands along the Danube. During this study, Festuca wagneri and Festuca tomanii were identified as potentially suitable grass species for urban planting and turf establishment based on preliminary research. Our aim was to determine the germination success of seeds from aesthetically selected individuals and to identify the growing media on which they germinate most effectively. From the collected Festuca individuals, we analyzed 30 specimens of each taxon under garden conditions and selected the individuals for germination. The Festuca tomanii individuals were uniform, so we selected only 5 individuals. The Festuca wagneri individuals were categorized into three groups: leaves and inflorescence densely upright, inflorescence shoots spread out, and low 'dwarf' form (compact and dense but short in stature). It was assumed that Festuca species seeds would germinate better in sandy soils. To test our hypothesis, seeds from ten Festuca wagneri and five Festuca tomanii individuals, selected based on aesthetic criteria, were sown in six different substrates: a sand–peat mixture, sand, coconut fiber, peat, coconut fiber–sand mixture, and native sandy soil (Calcaric Arenosol). Contrary to our expectations, the growth and germination rates of seeds sown in peat and coconut fiber substrates were higher than those in native sandy soil. These results suggest that Festuca seeds germinate better on substrates resembling dead plant debris with a peat-like structure or on the surface of live mosses rather than on bare sand. Among the examined individuals, the seeds from the spreading Festuca wagneri group exhibited the highest germination rate, making this group particularly suitable for urban environments. Additionally, one of the upright Festuca wagneri individuals showed the highest leaf average length and should also be considered for urban planting. In contrast, despite their uniform appearance, the Festuca tomanii individuals did not demonstrate similar germination trends. In fact, the seeds from two clumps did not germinate at all, indicating that further research is necessary. [ABSTRACT FROM AUTHOR]

Statistical morphological variations at the population level serve as a robust foundation for species delimitation and taxonomic treatment. We employed this approach to investigate species delimitation within the Ptilagrostis dichotoma species complex (Poaceae), which is characterized by open panicles. While three species have been described, the boundaries between these species and the morphological distributions of all taxonomic traits remain unclear. In this study, we examined the geographical variability of 19 morphological traits based on at least six individuals from each of the 28 populations across the entire distributional range of the species complex. Our statistical analyses identified five distinct phenotypic clusters with specific geographical preferences. Three of these clusters corresponded to the previously described species, while the remaining two clusters represented previously undescribed species. Furthermore, our findings highlight several traits, such as basal leaf scabrosity, panicle branch pulvinae, and glume length, which exhibit distinct gaps between phenotypic units and prove highly valuable for species delimitation. Finally, two new species are described and a key is provided to differentiate the five species. This morphological revision establishes a basis for future studies on species boundaries and divergences of the complex based on other evidence. [ABSTRACT FROM AUTHOR]

Summary: C4 photosynthesis is a complex trait requiring multiple developmental and metabolic alterations. Despite this complexity, it has independently evolved over 60 times. However, our understanding of the transition to C4 is complicated by the fact that variation in photosynthetic type is usually segregated between species that diverged a long time ago.Here, we perform a genome‐wide association study (GWAS) using the grass Alloteropsis semialata, the only known species to have C3, intermediate, and C4 accessions that recently diverged. We aimed to identify genomic regions associated with the strength of the C4 cycle (measured using δ13C), and the development of C4 leaf anatomy.Genomic regions correlated with δ13C include regulators of C4 decarboxylation enzymes (RIPK), nonphotochemical quenching (SOQ1), and the development of Kranz anatomy (SCARECROW‐LIKE). Regions associated with the development of C4 leaf anatomy in the intermediate individuals contain additional leaf anatomy regulators, including those responsible for vein patterning (GSL8) and meristem determinacy (GIF1).The parallel recruitment of paralogous leaf anatomy regulators between A. semialata and other C4 lineages implies the co‐option of these genes is context‐dependent, which likely has implications for the engineering of the C4 trait into C3 species. [ABSTRACT FROM AUTHOR]

Copyright of Biomass Chemical Engineering is the property of Editorial Office of Biomass Chemical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Grasses (Poaceae) produce large amounts of pollen and are among the main causes of pollinosis worldwide. Despite their morphological similarity, pollen grains of different grass species may have different allergenicities. Therefore, quantification of the roles of individual species in airborne pollen is an important task. There are very few studies on this topic, and none of them have been conducted in a temperate continental climate. Our study was carried out for three years (2020–2022) in the urban territory of Moscow (Russia) and aimed to understand what grass species contribute the most to the total pollen load of the atmosphere. The comparison of aerobiological and phenological data was based on calculating the phenological index, which is a combination of phenological parameters, pollen productivity of individual species, and their abundance. Our data showed that the decomposition of pollination curves based on the phenological index was sometimes very efficient but not always possible in temperate continental climates. The main reasons for disagreement between aerobiological and phenological data were weather conditions and lawn mowing. Not all grasses were equally important as sources of allergenic pollen. The greatest contribution to the pollen load at the beginning of the season in Moscow was made by Dactylis glomerata, and to a lesser extent by Phleum pratense and Festuca pratensis. These are the most common species, which are widespread throughout Europe. The contribution of minor components is insignificant. [ABSTRACT FROM AUTHOR]

Copyright of Tropical Grasslands / Forrajes Tropicales is the property of International Centre for Tropical Agriculture - CIAT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The decline of oak canopies in Iberian woodlands is strongly influenced by abiotic and biotic stress factors, such as the oomycete Phytophthora cinnamomi which has the capacity to infect a wide range of plant species. Understory plant diversity plays an important role in the epidemiology of P. cinnamomi in these ecosystems. This study aimed to identify a set of woody and herbaceous plants that can impact oak decline. Twenty-two herbaceous plant species from three families, and nineteen woody plants (trees and shrubs) from seven families were assessed for their response to infection by P. cinnamomi. Most of the herbaceous species did not show evident susceptibility, only a few exhibited significant biomass root reduction and just seven were identified as hosts. Yellow lupin was the only herbaceous species showing high susceptibility. Among the woody plant species, only two shrub and two tree species exhibited disease symptoms. The other ones, mostly hosts, ranged between low susceptible and tolerant. These results highlight the possibility that many of these species can maintain the pathogen active in the soil or even increase its population. In this context, the findings of this study can contribute to effective management strategies to mitigate Phytophthora infection in woodland soils. [ABSTRACT FROM AUTHOR]

The article presents the results of a study of the synanthropic species Eriochloa villosa (Poaceae: Paniceae), which is currently spreading throughout Russia (including Siberia). On the basis of analysis of published data, herbarium materials, and our own observations in nature, the current distribution of this species in Siberia has been detailed. It was concluded that there are two current settlement centers of this species in Siberia, located in Altai and in Tomsk region. In Western Siberia, E. villosa successfully colonizes both segetal habitats (crops of various grains, row crops, and oilseeds) and ruderal habitats. Geobotanical descriptions were made of segetal communities with the participation of E. villosa, presumably belonging to the class of synanthropic vegetation Stellarietea mediae R. Tx. et al. ex von Roshow 1951. The main ways of distribution of diaspores for this species in Siberia are speirochory and agestochory. For E. villosa seeds, a state of shallow physiological dormancy and their high germination rate in laboratory conditions have been revealed. The data obtained can be used to take measures to control the number of this segetal species in agricultural crops. [ABSTRACT FROM AUTHOR]

Transposable elements (TEs) contribute to intraspecific variation and play important roles in the evolution of fungal genomes. However, our understanding of the processes that shape TE landscapes is limited, as is our understanding of the relationship between TE content, population structure, and evolutionary history of fungal species. Fungal plant pathogens, which often have host-specific populations, are useful systems in which to study intraspecific TE content diversity. Here, we describe TE dynamics in five lineages of Magnaporthe oryzae, the fungus that causes blast disease of rice, wheat, and many other grasses. We identified differences in TE content across these lineages and showed that recent lineage-specific expansions of certain TEs have contributed to overall greater TE content in rice-infecting and Setaria-infecting lineages. We reconstructed the evolutionary histories of long terminal repeat-retrotransposon expansions and found that in some cases they were caused by complex proliferation dynamics of one element and in others by multiple elements from an older population of TEs multiplying in parallel. Additionally, we found evidence suggesting the recent transfer of a DNA transposon between rice- and wheat-infecting M. oryzae lineages and a region showing evidence of homologous recombination between those lineages, which could have facilitated such a transfer. By investigating intraspecific TE content variation, we uncovered key differences in the proliferation dynamics of TEs in various pathotypes of a fungal plant pathogen, giving us a better understanding of the evolutionary history of the pathogen itself.

Abstract Background A new species of smut fungus, Urocystis heteropogonis, was discovered infecting Heteropogon contortus in Shawar Valley, Swat district, Khyber Pakhtunkhwa, Pakistan. The study aimed to characterize this fungus based on its morpho-anatomical and molecular features and clarify its phylogenetic position within the genus Urocystis. Results Urocystis heteropogonis was identified as a novel species, distinct from other Urocystis species. Morphologically, it is characterized by larger spore balls (14–69 × 11–45 μm) and central spores that are 14–28 × 11–20 μm in size, with each spore containing1–8 central spores. The spore walls measure 0.9–2.5 μm in thickness and the species differs in infection patterns compared to other Urocystis species. Phylogenetic analysis based on the ITS and LSU regions of nuclear ribosomal DNA (nrDNA) further confirmed the novelty of the species, placing it within a distinct clade alongside U. agropyri, U. occulta, U. piptatheri, and U. tritici. Conclusions The discovery of Urocystis heteropogonis adds to the diversity of smut fungi infecting grasses and highlights the need for further research into its ecological and agricultural implications. Future studies should focus on the disease’s spread, management, and potential impact on host populations.

Hordeum pusillum (Hordeum pusillum Nutt., 1818) is an annual barley that is native to the west of the North America and widespread in southern United States and tropical America. In this study, we have provided the first complete characterization of the chloroplast genome of H. pusillum. Our research revealed that the circular chloroplast genome of H. pusillum consists of a large single-copy region (LSC: 80,853 bp), a small single-copy region (SSC: 12,745 bp), and a pair of inverted repeat regions (IRs: 21,587 bp), totaling 136,772 bp in length. Within the chloroplast genome of H. pusillum, 91 protein-coding genes, 38 tRNA genes, and ten rRNA genes were identified. To determine the evolutionary relationship of Hordeum species with reported chloroplast genome sequences, we constructed a phylogenetic tree using the entire chloroplast genome sequences. The evolutionary position of H. pusillum corresponds to its geographical location. The chloroplast genome of H. pusillum provided in this study may have significant implications for the phylogenetic study of Poaceae species.

Five new glycosides, namely methyl 3-methoxybenzoate-4,5-di-O-β-D-glucopyranoside (1), (1aS,3aS,3R)-3-(4'-O-β-D-glucopyranosyl-3'-methoxyphenyl)-5,6-dioxa-bicyclo[3.3.0]octane-1-one (2), quinolin-4(1H)-one-3-O-β-D-glucopyranoside (3), 3-methoxy-propiophenone 4-O-(6'-β-D-xylopyranosyl)-β-D-glucopyranoside (4), methyl 3-methoxybenzoate 4-O-(6'-β-D-xylopyranosyl)-β-D-glucopyranoside (5), and one known compound, bambulignan B (6) were isolated from the culms of Phyllostachys nigra var. henonis. Their structures were determined using spectroscopic analysis. All compounds were evaluated for their DPPH radical scavenging activity. Compound 6 exhibited antioxidant activity with IC50 value of 59.5 μM (positive control, L-ascorbic acid, IC50 = 12.4 μM; 2,6-ditertbutyl-4-methyl phenol, IC50 = 11.8 μM). [ABSTRACT FROM AUTHOR]

The excessive tyrosinase activity has been linked to the overproduction of melanin which can lead to hyperpigmentation, oxidative stress, browning, and an increased risk of melanoma. Due to these detrimental effects associated with the overexpression of tyrosinase, research efforts are focused on finding bioactive compounds that can inhibit this enzyme efficiently. This study, conducted to find tyrosinase inhibitors utilizing the shoots of Gigantochloa levis (G. levis), produced three previously undescribed benzylidene derivatives (1–3) and two known compounds, with promising anti-tyrosinase activity. The new compounds were designated as gigantolevisins A–C, and the two known compounds as (E)-3-(4-hydroxyphenyl)-2-phenylacrylaldehyde (4) and (E)-2,3-bis(4-hydroxyphenyl)acrylaldehyde (5), respectively, based on the spectroscopic data and X-ray crystallographic analysis. The isolated compounds showed inhibition effects against tyrosinase, ranging from 42 % to 58 % (IC 50 values of >400–286 ± 15 μM) in comparison to the positive control Kojic acid with 100 % inhibition (IC 50 value of 43 ± 3 μM). The findings suggest that, while the isolated compounds are less potent than Kojic acid, they can be effective in inhibiting tyrosinase activity. Thus, the study highlights the therapeutic potential of G. levis shoots for treating melanin-related conditions. [Display omitted] • Three new benzylidene derivatives were isolated from the shoots of Gigantochloa levis. • Their structures were elucidated based on analysis of their spectroscopic data. • The isolated compounds exhibited inhibitory activity against the enzyme tyrosinase. • A possible biosynthetic pathway is proposed. [ABSTRACT FROM AUTHOR]

The decline of oak canopies in Iberian woodlands is strongly influenced by abiotic and biotic stress factors, such as the oomycete Phytophthora cinnamomi which has the capacity to infect a wide range of plant species. Understory plant diversity plays an important role in the epidemiology of P. cinnamomi in these ecosystems. This study aimed to identify a set of woody and herbaceous plants that can impact oak decline. Twenty-two herbaceous plant species from three families, and nineteen woody plants (trees and shrubs) from seven families were assessed for their response to infection by P. cinnamomi. Most of the herbaceous species did not show evident susceptibility, only a few exhibited significant biomass root reduction and just seven were identified as hosts. Yellow lupin was the only herbaceous species showing high susceptibility. Among the woody plant species, only two shrub and two tree species exhibited disease symptoms. The other ones, mostly hosts, ranged between low susceptible and tolerant. These results highlight the possibility that many of these species can maintain the pathogen active in the soil or even increase its population. In this context, the findings of this study can contribute to effective management strategies to mitigate Phytophthora infection in woodland soils.

Abstract Phytoremediation is a basic eco-friendly technique that uses to treat contaminated water and soil. The plants that remediate the water and soil by their absorption process and improve the water and sediment fertility or decrease the contamination. Form this experiment our finding suggest that the contamination decrease in majority from starting point to end point, it means plants plays the most important role in clean-up the environment and its cost-efficient method to improve the quality of water and soil. This study was carried out on Uben River which is around 50kms long and we covered around 41.88kms of area which divided into six locations. in soil minerals (Ca2+, Mg2+, Na+ and K+) from Up-stream to Down-stream the concentration of minerals is in decreasing order but in heavy metals (Cu2+, Zn2+, Fe2+ and Mn2+) the concentration data is varying. We selected plants that grow around riverbanks belongs to family Cyperaceae, Poaceae, Typhaceae. Most of the plants accumulate high Fe2+ concentrations in their root while in the shoots have low concentration observed from our data. For the statistical validation of data, we perform Grouped Component Analysis (GCA) and Radial Cluster Hierarchy (RCH) analysis. Further we included pollution indices: Contamination factor (CF), Degree of contamination (C d), Geo accumulation index (Igeo).

During an ongoing survey on fungal diversity in Sichuan Province, China, a white filamentous fungus growing on decaying marbled bamboo (Chimonobambusa marmoreal) leaves was collected. Upon conducting the initial morphological diagnosis and BLASTn searches, the new collection was assigned to the genus Arthrobotrys. A multi-locus phylogeny, based on a concatenated dataset (SSU-ITS-LSU-TEF1-RPB2), revealed the new collection in close phylogenetic proximity to Arthrobotrys eryuanensis and A. hyrcanus. However, they differ in shape and size of conidia. The conidia of the new collection are comparatively shorter than those of A. hyrcanus and wider than those of A. eryuanensis. Based on the difference in morphology and molecular data, we proposed the new collection as a new species, Arthrobotrys chinensis sp. nov. Detailed morphological characteristics, illustrations, and an updated phylogeny is provided for the new species. [ABSTRACT FROM AUTHOR]

The pollen wall protects pollen during dispersal and is critical for pollination recognition. In the Poaceae family, the pollen exine stereostructure exhibits a high degree of conservation with similar patterns across species. However, there remains controversy regarding the conservation of key factors involved in its formation among various Poaceae species. EPAD1, as a gene specific to the Poaceae family, and its orthologous genes play a conserved role in pollen wall formation in wheat and rice. However, they do not appear to have significant functions in maize. To further confirm the conserved function of EPAD1 in Poaceae, we performed an analysis on four EPAD1 orthologs from two distinct sub-clades within the Poaceae family. The two functional redundant barley EPAD1 genes (HvEPAD1 and HvEPAD2) from the BOP clade, along with the single copy of sorghum (SbEPAD1) and millet (SiEPAD1) from the PACMAD clade were examined. The CRISPR-Cas9-generated mutants all exhibited defects in pollen wall formation, consistent with previous findings on EPAD1 in rice and wheat. Interestingly, in barley, hvepad2 single mutant also showed apical spikelets abortion, aligning with a decreased expression level of HvEPAD1 and HvEPAD2 from the apical to the bottom of the spike. Our finding provides evidence that EPAD1 orthologs contribute to Poaceae specific pollen exine pattern formation via maintaining primexine integrity despite potential variations in copy numbers across different species. [ABSTRACT FROM AUTHOR]

Phyllachora (Phyllachoraceae, Phyllachorales) species are parasitic fungi with a wide global distribution, causing tar spots on plants. In this study, we describe three newly discovered species: Phyllachora chongzhouensis, Phyllachora neidongensis, and Phyllachora huiliensis from Poaceae in China. These species were characterized using morphological traits and multi-locus phylogeny based on the internal transcribed spacer region (ITS) with the intervening 5.8S rRNA gene, the large subunit of the rRNA gene (LSU), and the 18S ribosomal RNA gene (SSU). Three known species of P. chloridis, P. graminis, and P. miscanthi have also been redescribed, because, in reviewing the original references of P. chloridis, P. graminis, and P. miscanthi, these were found to be relatively old and in Chinese or abbreviated. In addition, the illustrations were simple. In molecular identification, the ITS sequence is short, while the ITS, LSU, and SSU are incomplete. Therefore, this study provides new important references for the redescription of three known species and provides further evidence for the identification of new taxa. [ABSTRACT FROM AUTHOR]

The genus Clavibacter (family Microbacteriaceae) includes gram‐positive actinobacterial species infecting diverse agricultural crops such as alfalfa, maize, pepper, potato, tomato and wheat. Clavibacter tessellarius, causing bacterial mosaic of wheat, was reported for the first time in 1976 in Nebraska (United States). Since then, the pathogen was thought to be restricted to North America (Canada and the United States). While bacterial strains suspected to be C. tessellarius have occasionally been isolated from wheat samples outside North America, occurrence of the pathogen in the Old World has not yet been confirmed by the plant protection authorities. In spring 2020 (January to May) dozens of wheat fields with young plants showing leaf chlorosis and mild mosaic symptoms were surveyed and sampled in southern Iran. Among 192 surveyed wheat fields, gram‐positive, orange‐pigmented actinobacterial strains were isolated from samples of 53 fields. Altogether, 61 bacterial strains were identified as C. tessellarius based on the phenotypic features, PCR‐based molecular tests and pathogenicity assays. Multilocus sequence analysis of five housekeeping genes (atpD, dnaK, gyrB, ppk and rpoB) using 10 representative strains from diverse geographic areas in southern Iran confirmed the phylogenetic status of the strains within C. tessellarius. Our data indicate that the bacterial mosaic pathogen occurs in four southern Iranian provinces including Bushehr, Fars, Kerman and Khuzestan. Thus, occurrence of C. tessellarius outside North America is confirmed. Potential risks associated with the emergence of the pathogen in the Old World, and the need for strict quarantine measures in the area, is further discussed. [ABSTRACT FROM AUTHOR]

Premise: The proportion of polyploid plants in a community increases with latitude, and different hypotheses have been proposed about which factors drive this pattern. Here, we aimed to understand the historical causes of the latitudinal polyploidy gradient using a combination of ancestral state reconstruction methods. Specifically, we assessed whether (1) polyploidization enables movement to higher latitudes (i.e., polyploidization precedes occurrences in higher latitudes) or (2) higher latitudes facilitate polyploidization (i.e., occurrence in higher latitudes precedes polyploidization). Methods: We reconstructed the ploidy states and ancestral niches of 1032 angiosperm species at four paleoclimatic time slices ranging from 3.3 million years ago to the present, comprising taxa from four well‐represented clades: Onagraceae, Primulaceae, Solanum (Solanaceae), and Pooideae (Poaceae). We used ancestral niche reconstruction models alongside a customized discrete character evolution model to allow reconstruction of states at specific time slices. Patterns of latitudinal movement were reconstructed and compared in relation to inferred ploidy shifts. Results: No single hypothesis applied equally well across all analyzed clades. While significant differences in median latitudinal occurrence were detected in the largest clade, Poaceae, no significant differences were detected in latitudinal movement in any clade. Conclusions: Our preliminary study is the first to attempt to connect ploidy changes to continuous latitudinal movement, but we cannot favor one hypothesis over another. Given that patterns seem to be clade‐specific, more clades must be analyzed in future studies for generalities to be drawn. [ABSTRACT FROM AUTHOR]

Phytoremediation is a basic eco-friendly technique that uses to treat contaminated water and soil. The plants that remediate the water and soil by their absorption process and improve the water and sediment fertility or decrease the contamination. Form this experiment our finding suggest that the contamination decrease in majority from starting point to end point, it means plants plays the most important role in clean-up the environment and its cost-efficient method to improve the quality of water and soil. This study was carried out on Uben River which is around 50kms long and we covered around 41.88kms of area which divided into six locations. in soil minerals (Ca2+, Mg2+, Na+ and K+) from Up-stream to Down-stream the concentration of minerals is in decreasing order but in heavy metals (Cu2+, Zn2+, Fe2+ and Mn2+) the concentration data is varying. We selected plants that grow around riverbanks belongs to family Cyperaceae, Poaceae, Typhaceae. Most of the plants accumulate high Fe2+ concentrations in their root while in the shoots have low concentration observed from our data. For the statistical validation of data, we perform Grouped Component Analysis (GCA) and Radial Cluster Hierarchy (RCH) analysis. Further we included pollution indices: Contamination factor (CF), Degree of contamination (Cd), Geo accumulation index (Igeo). [ABSTRACT FROM AUTHOR]

Chloroplasts and mitochondria, descendants of ancient prokaryotes via endosymbiosis, occupy a pivotal position in plant growth and development due to their intricate connections with the nuclear genome. Genes encoded by the nuclear genome but relocated to or being functional within these organelles are commonly referred as organelle-targeting nuclear genes (ONGs). These genes are essential for maintaining cytonuclear coordination, thereby determining the stability of the life cycle. While molecular function and cytonuclear coordination of some endosymbiosis-derived ONGs (E-ONGs) have been extensively studied, the evolutionary history and characteristics from a more widespread range of non-endosymbiosis-derived ONGs (NE-ONGs) remain largely enigmatic. In this study, we focused on 12 representative species within the Poaceae family to systematically identify NE-ONGs and investigated their evolutionary history and functional significance on a phylogenetic timescale. Upon aligning these 12 species' evolutionary histories, we observed the following phenomena: (i) an exploration of NE-ONGs between the BOP and PACMAD clades unveiled dynamic compositions, potentially influencing their photosynthetic divergence; (ii) the majority of the abundant species-specific NE-ONGs exist in a single-copy status, and functional enrichment analysis further underscored their specialized roles, which could be crucial for species adaptation; and (iii) comparative analyses between plasmid- and mitochondria-related NE-ONGs (pNE-ONGs and mNE-ONGs) revealed a prevalence of pNE-ONGs, indicating tighter control for chloroplast function in Poaceae. In summary, this study offers novel insights into the cytonuclear co-evolutionary dynamics in Poaceae speciation and draws attention to crop improvement by using NE-ONGs. [ABSTRACT FROM AUTHOR]

The potential for rapid evolution is an important mechanism allowing species to adapt to changing climatic conditions. Although such potential has been largely studied in various short-lived organisms, to what extent we can observe similar patterns in long-lived plant species, which often dominate natural systems, is largely unexplored. We explored the potential for rapid evolution in Festuca rubra , a long-lived grass with extensive clonal growth dominating in alpine grasslands. We used a field sowing experiment simulating expected climate change in our model region. Specifically, we exposed seeds from five independent seed sources to novel climatic conditions by shifting them along a natural climatic grid and explored the genetic profiles of established seedlings after 3 years. Data on genetic profiles of plants selected under different novel conditions indicate that different climate shifts select significantly different pools of genotypes from common seed pools. Increasing soil moisture was more important than increasing temperature or the interaction of the two climatic factors in selecting pressure. This can indicate negative genetic interaction in response to the combined effects or that the effects of different climates are interactive rather than additive. The selected alleles were found in genomic regions, likely affecting the function of specific genes or their expression. Many of these were also linked to morphological traits (mainly to trait plasticity), suggesting these changes may have a consequence on plant performance. Overall, these data indicate that even long-lived plant species may experience strong selection by climate, and their populations thus have the potential to rapidly adapt to these novel conditions. [ABSTRACT FROM AUTHOR]

Worldwide molecular research of economically important Phalaris arundinacea (Poaceae) is mainly focused on the invasions of this species from Europe to North America. Until the present study, the genetic diversity of the P. arundinacea had not been studied across the Baltic countries. The objective of this research is to evaluate the diversity of Lithuanian populations of P. arundinacea at simple sequence repeat (SSR) loci comparatively among populations of the Baltic countries, Luxembourg, and the Russian Far East (Eurasian), evaluating differentiation between Lithuanian populations and ornamental accessions, and relating these with environmental features. For six selected Lithuanian river basin populations, GBS low density SNPs were used to determine genetic diversity. Bayesian analysis showed that Eurasian populations of Phalaris arundinacea consist of two gene clusters. Statistically significant genetic differentiation among European and Eurasian populations was documented. Lithuanian genotypes growing naturally along rivers are genetically distinct from cultivated ornamentals. GBS-SNPs divided the six selected Nemunas river basins into three distinct groups with one, two, or three rivers in separate groupings for genetic diversity. Genetic diversity is primarily within, rather than among, Lithuanian, eastern European, and Eurasian populations of P. arundinacea across the continent. Thus, restoration efforts would benefit from local population seed origination. [ABSTRACT FROM AUTHOR]

In savanna ecosystems, the seasonal effects of nitrogen forms and availability, as well as their utilization by plants, influence the abundance and distribution of herbaceous species in grassland communities. This study examines seasonal effects on nitrogen availability and utilization by native grass species in the Cerrado, a savanna ecosystem in Brazil. Ammonium and nitrate levels in soil, nitrate acquisition and transport, and Nitrate Reductase Activity (NRA) in different plant parts during dry and wet periods were assessed. Results indicated higher soil nitrate availability during the wet period, influenced by precipitation, with leaves showing a higher nitrate content compared to roots. There was seasonal modulation in nitrate reduction, with leaves being the primary site during the dry period and roots during the wet period. The studied grass species exhibited heterogeneous responses to seasonal nitrogen availability, potentially affecting community abundance patterns. Findings suggest that edaphoclimatic seasonality plays a crucial role in nitrogen distribution and utilization capacity by grass plants in the Cerrado, contributing to the understanding of these ecosystems' ecology. [ABSTRACT FROM AUTHOR]

A geobotanical analysis of 160 steppe and ecotone plant communities with the participation of cereals in the north of the Lower Volga region (within Saratov oblast) has been carried out. The species diversity of apomictic cereals is significantly inferior to the diversity of their amphimictic relatives in the flora of the region and in the studied phytocenoses (24 apomictic and 109 amphimictic species in the flora; 17 and 34 species in the phytocenoses, respectively). At the same time, the dominants of the studied communities are equally represented by both amphimictic (14 species) and apomictic cereals (9 species). It is established that cereals with an amphimictic mode of reproduction dominate in 64 phytocenoses and apomictic cereals dominate in 48 ones. The number of phytocenoses in which apomicts are codominants significantly exceeds the number of plant communities with amphimicts codominance (46 and 22, respectively). The studied plant communities are similar in species richness and evenness. The data indicate successful competition between apomictic cereals and amphimicts and their significant contribution to the composition of steppe and ecotone phytocenoses in the northern Lower Volga region. [ABSTRACT FROM AUTHOR]

Aerobiology could be used as complementary data or proxy for studying phenology, especially in species which usually are not long-distance transported, such as grasses. This 21-year aerobiological study took place in Évora (South Portugal), using a seven-day recording volumetric pollen trap with the aim of analysing the temporal trends of grass pollen seasons. To this end, data were statistically tested for correlation and regression to determine the features and temporal trends of pollen seasons. Main results show that Poaceae pollen has a high representation in pollen spectrum, 20% (min: 7%; max: 44%), with a long season starting in March and lasting till August/September or October. There was an overall, but not statistically significant trend, towards an increase in the annual pollen integral and peak values, and also an overall non-statistically significant trend towards an earlier start and later end of the pollen season. Main and high pollen seasons have been lasting longer, and the days with allergenic potential have been rising in line with the local temperature rising trend. It seems that grass pollen production is being aided by warmer temperatures and increased grassland areas in Alentejo region. This could promote the increase in annual pollen levels and in the number of high pollen days over the years. In clinical terms, it means that grass allergic patients are exposed to longer periods of airborne pollen and to higher counts over a longer time. The climate conditions projected for Alentejo region, including rising temperature, and the changes in local grassland areas may help to clarify the trends of grass pollen seasons in the next decades. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is frequently limiting to plant growth, in part because most soil N is present as polymeric organic compounds that are not readily taken up by plants. Microbial depolymerization of these large macromolecular N-substrates gradually releases available inorganic N. While many studies have researched and modeled controls on soil organic matter formation and bulk N mineralization, the ecological-spatial, temporal and phylogenetic-patterns underlying organic N degradation remain unclear. We analyzed 48 time-resolved metatranscriptomes and quantified N-depolymerization gene expression to resolve differential expression by soil habitat and time in specific taxonomic groups and gene-based guilds. We observed much higher expression of extracellular serine-type proteases than other extracellular N-degrading enzymes, with protease expression of predatory bacteria declining with time and other taxonomic patterns driven by the presence (Gammaproteobacteria) or absence (Thermoproteota) of live roots and root detritus (Deltaproteobacteria and Fungi). The primary chitinase chit1 gene was more highly expressed by eukaryotes near root detritus, suggesting predation of fungi. In some lineages, increased gene expression over time suggests increased competitiveness with rhizosphere age (Chloroflexi). Phylotypes from some genera had protease expression patterns that could benefit plant N nutrition, for example, we identified a Janthinobacterium phylotype and two Burkholderiales that depolymerize organic N near young roots and a Rhizobacter with elevated protease levels near mature roots. These taxon-resolved gene expression results provide an ecological read-out of microbial interactions and controls on N dynamics in specific soil microhabitats and could be used to target potential plant N bioaugmentation strategies.

Poa pratensis, commonly known as Kentucky bluegrass, is a popular cool-season grass species used as turf in lawns and recreation areas globally. Despite its substantial economic value, a reference genome had not previously been assembled due to the genome's relatively large size and biological complexity that includes apomixis, polyploidy, and interspecific hybridization. We report here a fortuitous de novo assembly and annotation of a P. pratensis genome. Instead of sequencing the genome of a C4 grass, we accidentally sampled and sequenced tissue from a weedy P. pratensis whose stolon was intertwined with that of the C4 grass. The draft assembly consists of 6.09 Gbp with an N50 scaffold length of 65.1 Mbp, and a total of 118 scaffolds, generated using PacBio long reads and Bionano optical map technology. We annotated 256K gene models and found 58% of the genome to be composed of transposable elements. To demonstrate the applicability of the reference genome, we evaluated population structure and estimated genetic diversity in P. pratensis collected from three North American prairies, two in Manitoba, Canada and one in Colorado, USA. Our results support previous studies that found high genetic diversity and population structure within the species. The reference genome and annotation will be an important resource for turfgrass breeding and study of bluegrasses.

ABSTRACT A scientific note is presented, commenting on the presence of Aristida achalensis Mez (Poaceae, Aristidoideae) and discussing the most related species within Peru. With the new taxon included the number of Aristida species in Peru increases to 21, and the distribution range of A. achalensis expands to South America, initially reported for Argentina, Bolivia, and Brazil. This work includes a key that allows us to differentiate the species with a column between the lemma and the awns occurring in Peru.

Bahiagrass (Paspalum notatum Flüggé), native to Brazil, was once widely used in landscaping and is currently more commonly found along roadsides and in large urban areas with old plantings, such as squares, parks, public and industrial areas, among others. Brazil has been developing research into the selection of varieties of this grass, and it is important to know about seed germination in this process and also in commercial multiplication, aiming to form high-quality lawns, quickly and sustainably. Thus, the objective of this research was to evaluate factors that affect the germination of bahiagrass seeds, such as temperature, saline stress, sowing method and water availability in the substrate. Five temperature conditions were studied (room temperature, 25 °C, 30 °C, 20-30 °C, and 25-35 °C); in the salt stress study, five treatments were applied, including a control (absence) and four NaCl concentrations (25, 50, 75, and 100 mM). Two forms of sowing (on and between sand) were also studied, combined with four water contents (25%, 50%, 75%, and 100%) of the water retention capacity in sand. The germination percentage and the germination speed index (GSI) of the seeds were evaluated. The germination of P. notatum seeds was more effective at a temperature of 20-30 °C, in the absence of NaCl, and with a 25% water retention capacity in sand. Sowing in sand, with a water retention capacity of 100%, impairs the germination of bahiagrass seeds.

This document provides an overview of Miscanthus sinensis ‘Morning Light’, commonly known as ‘Morning Light’ maiden grass. It describes the plant’s physical characteristics, including its height, spread, and fine-textured foliage. The document highlights its ornamental uses in landscapes, such as mass planting, borders, and as an accent. It also covers the plant’s adaptability to various soil types, its drought tolerance, and its preference for full sun. Additionally, the document mentions the plant’s invasive potential and provides information on its propagation and pest resistance. Original publication date September 1999.

This document provides an overview of Miscanthus sinensis ‘Variegatus’, commonly known as variegated Japanese silver grass or maiden grass. It describes the plant’s distinctive features, including its variegated leaves, pink flowers, and upright growth habit. The document highlights its uses in landscaping, such as mass planting, borders, and as an accent plant. It also covers the plant’s adaptability to various soil types, its moderate drought tolerance, and its invasive potential. Additionally, it mentions other cultivars of Miscanthus sinensis and provides guidance on planting and maintenance. Original publication date October 1999.