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Sediment accretion (burial) and nutrient enrichment may exert a synergistic influence on the growth and distribution of macrophytes in floodplain wetlands; however, this phenomenon has rarely been examined. In this study, we investigated the effects of sediment accretion and nutrient enrichment on the growth and vegetative propagation of Phalaris arundinacea within a Carex thunbergii stand (one P. arundinacea ramet within 25 C. thunbergii ramets) using a factorial sediment burial (0, 3, and 6 cm) and nutrient addition (low, medium, and high) experimental design. High sediment burial (6 cm) without nutrient addition decreased the aboveground and total biomass of C. thunbergii but did not affect P. arundinacea, indicating that P. arundinacea is more tolerant to sediment burial than C. thunbergii. Moderate sediment burial (3 cm) with nutrient addition enhanced the aboveground and total biomass of P. arundinacea but did not affect C. thunbergii, indicating that P. arundinacea may gain a growth advantage over C. thunbergii under moderate sedimentation. High sediment burial with nutrient addition increased the number of rhizomes and ramets produced by P. arundinacea but did not affect C. thunbergii, indicating that the relative abundance of P. arundinacea may increase within the Carex community under high sedimentation conditions. Based on these results, it can be concluded that an increased sedimentation rate facilitates the invasion of P. arundinacea into Carex grasslands, and this invasion is further enhanced by nutrient enrichment. Therefore, management measures should be taken to reduce the sediment load and nutrient input to prevent Carex grasslands invasion by P. arundinacea and maintain the ecological function of floodplain wetlands. [ABSTRACT FROM AUTHOR]

Introduction: In recent years, the visible light intensity of lawns has significantly decreased due to obstructions caused by urban shading objects. Carex has a competitive advantage over other turfgrass in low-light conditions and extensive management. Therefore, exploring their survival strategy in low-light environments is of great significance. Methods: This study focuses on two species of Carex, Carex parva and Carex scabrirostris, and investigates their response to low-light conditions (150 mmol/m2/s) by simulating urban lawn conditions. Biomass allocation characteristics, leaf anatomical features, biochemical parameters, root morphology and photosynthetic parameters were measured. Results: (a) Peroxidase activity, specific leaf area, and relative water content are key factors influencing the photosynthetic capacity of the two Carex species. (b) Under low-light conditions, photosynthetic parameters, leaf physiological indicators, and biomass allocation of the two Carex species were significantly affected (p<0.05). Both Carex species increased their investment in leaf biomass, maintained lateral root growth, and cleared reactive oxygen species to maintain their physiological balance. (c) In the simulated urban low-light environment, neither C. parva nor C. scabrirostris produced dauciform roots. Discussion: In terms of response strategies, C. scabrirostris is a highphotosynthesis investing species with high productivity under low-light conditions, whereas C. parva exhibits minimal response, indicating a slow investment. C. scabrirostris has greater potential for application in low-light environments compared to C. parva. These results provide a theoretical basis for the cultivation and application of these two Carex species, as well as the expansion of turfgrass germplasm resources. [ABSTRACT FROM AUTHOR]

Theories explaining community assembly assume that biotic and abiotic filters sort species into communities based on the values of their traits and are thus based on between‐species trait variability (BTV). Nevertheless, these filters act on individuals rather than on species. Consequently, the selection is also influenced by intraspecific trait variability (ITV) and its drivers. These drivers may be abiotic (e.g., water availability) or biotic (e.g., competition). Although closely related species should have similar traits, many of them coexist. We investigated the relative magnitudes of BTV and ITV in coexisting closely related species and how their individual traits differ under different drivers of ITV. We manipulated conditions in a greenhouse pot experiment with four common Carex species, where individuals of each species originated from four source localities. Individuals were grown in factorial combinations of two moisture levels, with and without a competitor (grass species Holcus lanatus, a frequent competitor). We analyzed the variability of six morphological traits on individuals in the greenhouse and three morphological traits in the source localities. Species identity was the main determinant of differences in most traits. Competition exerted a greater effect than water availability. For leaf dry matter content (LDMC) and vegetative height, competition's effect even exceeded the variability among species. On the contrary, for specific leaf area (SLA) and clonal spread, the interspecific differences exceeded ITV induced by experimental treatments. SLA measured in the greenhouse closely correlated with values measured in field populations, while LDMC did not. The variability caused by source locality of ramets in the greenhouse was small, although sometimes significant. Closely related species differ in their traits, but for some traits, ITV can exceed BTV. We can expect that ITV can modify the processes of community assembly, particularly among coexisting closely related species. [ABSTRACT FROM AUTHOR]

Stilbenes in the roots of Carex acuta and Carex lepidocarpa were studied. Root samples were extracted with 100% methanol and analyzed by HPLC and LC-MS. In this way, trans-resveratrol dimers (m/z 455 Da [M + H]+), trimers (m/z 681 Da [M + H]+) and tetramers (m/z 907 Da [M + H]+) were identified in the extracts. Using LC-NMR in stop-flow mode, pallidol and trans-ε-viniferin as dimers were identified. After the separation of individual peaks and their measurement by 1H NMR, cis and trans-miyabenol A as a tetramer and cis-miyabenol C as a trimer were identified. In the case of miyabenol A, it is a chromatographically inseparable mixture of cis and trans isomers in the ratio of 2:3 according to 1H NMR measurement. In the case of cis-miyabenol C, the Z-trans-trans-miyabenol C configuration was confirmed. The remaining unidentified peak with a practically identical UV-VIS spectrum to that of cis-miyabenol C is most likely another isomer of miyabenol C. [ABSTRACT FROM AUTHOR]

Elongated biconvex Carex fossil fruits are relatively common in fossil assemblages, but they are of much uncertain taxonomic affinity. Three fossil-species have been erected to accommodate the materials from the respective type localities (C. klarae, C. paucifloriformis and C. paucifloroides) and a number of superficially similar-looking fossils were reported from other sites. The formerly proposed affinities mostly pointed to the extant C. pauciflora (subgen. Euthyceras) or Carex sect. Cyperoideae (subgen. Vignea), depending on the authors. But despite the similar superficial resemblance of the fossil remains to these not very closely related sedge taxa, other groups are also possible matches. We used a comparative approach employing stereomicroscope and SEM to analyze the affinities of several Old World "mummified" fossils (ca. 23 to 0.1 Ma) of elongated biconvex fruits. Several samples showed a fair preservation of previously unattested microscopic characters. In particular, one of them allowed us to detect an indirect record of fine silica body morphologies (impressions) on the periclinal walls, which permitted the sound taxonomic placement of the remains from the Miocene of Siberia as a Carex sect. Cyperoideae. In all the other fossils analyzed, the epidermal cell outline and the central position of the main silica body were sufficient to discard assignment to subgen. Euthyceras, despite a purported affinity to C. pauciflora reported in previous literature. In the absence of detailed information on silica bodies, epidermal cell (exocarp) details in fossil specimens do not seem to be determinant for the systematic placement. However, the addition of diagnostic style characters pointed to sect. Cyperoideae as the best match with the available information. Our data support a continued presence of Carex sect. Cyperoideae in the Old World since the Miocene, which candidates Eurasia as a possible place of origin for it, despite DNA-based reconstructions alone proposed North America. This study underlines the importance of detailed taxonomic studies to properly address the identity of fossils and unravel the biogeographic history of plants. [ABSTRACT FROM AUTHOR]

As a widely distributed plant in Northeast China, Carex meyeriana Kunth (CMK) is generally considered to have antibacterial properties; however, there is a lack of scientific evidence for this. Therefore, we investigated the chemical composition of CMK extract and its effect against C. albicans. A total of 105 compounds were identified in the alcohol extracts of CMK by UPLC-Q-TOF-MS. Most were flavonoids, with Luteolin being the most represented. Among them, 19 compounds are found in the C. albicans lysates. After treatment with CMK ethanol extract, a significant reduction in the number of C. albicans colonies was observed in a vaginal douche solution from day 5 (p < 0.05). Furthermore, the CMK extract can reduce the number of C. albicans spores. The levels of IL-4, IL-6, IL-10, IL-1β, and TNF-α in vaginal tissues all exhibited a significant decrease (p < 0.05) compared to those in the model group as determined by ELISA. The results of HE staining showed that CMK extract can eliminate vaginal mucosa inflammation. CMK adjusts the vaginal mucosa cells by targeting twenty-six different metabolites and five specific metabolic pathways in order to effectively eliminate inflammation. Simultaneously, the CMK regulates twenty-three types of metabolites and six metabolic pathways against C. albicans infection. So, CMK strongly inhibits the growth of C. albicans and significantly reduces vaginal inflammation, making it a promising candidate for treating C. albicans infection. [ABSTRACT FROM AUTHOR]

Purpose: Subtropical lake riparian ecosystems experience seasonal water table fluctuations and increased nitrogen (N) deposition with changing N composition. However, the interplay of soil water content (SWC), N deposition chemical composition, and their interaction on plant growth through regulating N acquisition remains poorly understood. Methods: In this controlled experiment with a sedge species Carex thunbergii, we investigated two treatment factors: (1) SWC at 100%, 60%, and 30% of field capacity, combined with (2) N treatments with NH4+:NO3− ratios of 1:3, 2:2, and 3:1. Treatment verifications were conducted using 15N isotope tracer (15NH4NO3 and NH415NO3) technology. Results: Results showed a notable trend of reduced biomass of C. thunbergii with increasing NH4+: NO3− ratio, especially under high SWC conditions. This negative effect of a high NH4+: NO3− ratio on plant biomass accumulation also aligned with reduced N use efficiency (NUE). Conversely, C. thunbergii exhibited accelerated N uptake with increasing SWC, with the most pronounced response observed in the treatment of NH4+: NO3− ratio of 3:1. Principal component analyses provided evidence for SWC-dominated functional coordination between plant below- and aboveground parts in mediating plant N acquisition, while correlation analyses revealed that NUE mainly contributed to belowground productivity of C. thunbergii. Conclusions: Our findings suggest that manipulating water table (as a proxy of SWC) and managing soil NH4+: NO3− ratios could optimize the productivity of this sedge species in riparian ecosystem. The coordination of leaf-root trait highlights the necessity to integrate above- and belowground traits for a comprehensive understanding of plant N acquisition strategies. Understanding plant N acquisition and use efficiency may help us better predict the potential impacts of future climate change components on ecosystem functions. [ABSTRACT FROM AUTHOR]

A search of herbarium data repositories available online revealed a notable collection of Carex scirpoidea (Cyperaceae) made by Joachim Heinrich Schuette in 1884 from Brown Co., Wisconsin, USA. This accession is the first and only known record of this now extirpated species from the state. While this locality represents a modest expansion of the known range of C. scirpoidea, errors in the aforementioned databases resulting from the complex nomenclatural history of this taxon confound our understanding of its distribution, particularly along its southern edge in the Midwest and Eastern North America. [ABSTRACT FROM AUTHOR]

Background: Phosphorus in the soil is mostly too insoluble for plants to utilize, resulting in inhibited aboveground biomass, while Carex can maintain their aboveground biomass through the presence of dauciform roots. However, dauciform roots lead to both morphological and physiological changes in the root system, making their primary mechanism unclear. Methods: A greenhouse experiment was conducted on three Carex species, in which Al-P, Ca-P, Fe-P, and K-P were employed as sole phosphorus sources. The plants were harvested and assessed after 30, 60 and 90 days. Results: (1) The density of dauciform roots was positively correlated with root length and specific root length, positively influencing aboveground biomass at all three stages. (2) The aboveground phosphorus concentration showed a negative correlation with both dauciform root density and aboveground biomass in the first two stages, which became positive in the third stage. (3) Aboveground biomass correlated negatively with the aboveground Al concentration, and positively with Ca and Fe concentration (except Al-P). (4) Root morphological traits emerged as critical factors in dauciform roots' promotion of aboveground biomass accumulation. Conclusion: Despite the difference among insoluble phosphorus, dauciform roots have a contributing effect on aboveground growth status over time, mainly by regulating root morphological traits. This study contributes to our understanding of short-term variation in dauciform roots and their regulatory mechanisms that enhance Carex aboveground biomass under low available phosphorus conditions. [ABSTRACT FROM AUTHOR]

Carex dianae Steud. is an endemic sedge of St. Helena, an isolated island in the South Atlantic. Our study provides the first molecular sequence data for this taxon. We generated sequence data for plastid matK and trnK regions and nuclear internal transcribed spacer and external transcribed spacer regions to determine the placement of C. dianae in the broader Carex phylogeny. The placement of C. dianae falls within Carex sect. Spirostachyae Drejer, and it is sister to a clade including Carex clavata Thunb., Carex aethiopica Schkuhr (both from the Cape region of S. Africa), and Carex gunniana Boott (southern Australia). The existence of three divergent nucleotype groups and two plastotypes is revealed from genetic variation within C. dianae. The results suggest that the ancestor of C. dianae likely originated in the Cape region of South Africa, followed by transoceanic dispersal to St. Helena estimated at 4.4–4.9 million years ago, likely by a bird vector. The most divergent population is that on an isolated hill known as "The Barn", which may represent a distinct taxon. The existence of highly structured molecular variation within an island only 16 km long is discussed. [ABSTRACT FROM AUTHOR]

The smut fungal genus Anthracoidea contains more than 100 species that parasitize hosts predominantly in the sedge genus Carex. Anthracoidea species are mainly found in the boreal zones of the Northern Hemisphere and many species have an arctic-alpine distribution. Recent re-organization of the taxonomy of the main host genus Carex questions current understanding of host associations in Anthracoidea. Host specificity for many of the species in this genus is considered to be quite broad and a host spectrum of over 10 host species is common. One aim of the study is to understand the potential influence that host taxonomy has on the evolutionary patterns of Anthracoidea. Additionally, by including more specimens, we clarify host specificity and species delimitation in Anthracoidea sempervirentis, a prevalent species occurring on different host species in different Carex subgroups using molecular data. Host colonization patterns within Anthracoidea are complex, and different subclades of Carex have been colonized several times independently, whereas clades of related Anthracoidea species often occur on Carex species from the same host clade. Parasites previously thought to be Anthracoidea sempervirentis occurring on the different Carex host are shown to be at least four distinct species that are restricted to individual host species. Three new species, Anthracoidea ferrugineae on Carex ferruginea from the Alps and the Carpathians, A. firmae on Carex firma from the Alps, and A. kitaibelianae on Carex kitaibeliana from mountains in the Balkan Peninsula, are described and illustrated. An emended description of Anthracoidea sempervirentis is also provided. Anthracoidea sempervirentis in its emended circumscription consists of two clades that correspond to respective clades within Carex sempervirens. The study shows that host colonization in Anthracoidea is more complex than current host taxonomy suggests. Further, including several specimens per host species results in a much higher diversity within Anthracoidea than previously assumed. [ABSTRACT FROM AUTHOR]

Background and Aims Despite chromosomal evolution being one of the major drivers of diversification in plants, we do not yet have a clear view of how new chromosome rearrangements become fixed within populations, which is a crucial step forward for understanding chromosomal speciation. Methods In this study, we test the role of genetic drift in the establishment of new chromosomal variants in the context of hybrid dysfunction models of chromosomal speciation. We genotyped 178 individuals from seven populations (plus 25 seeds from one population) across the geographical range of Carex helodes (Cyperaceae). We also characterized karyotype geographical patterns of the species across its distribution range. For one of the populations, we performed a detailed study of the fine-scale, local spatial distribution of its individuals and their genotypes and karyotypes. Key Results Synergistically, phylogeographical and karyotypic evidence revealed two main genetic groups: southwestern Iberian Peninsula vs. northwestern African populations; and within Europe our results suggest a west-to-east expansion with signals of genetic bottlenecks. Additionally, we inferred a pattern of descending dysploidy, plausibly as a result of a west-to-east process of post-glacial colonization in Europe. Conclusions Our results give experimental support to the role of geographical isolation, drift and inbreeding in the establishment of new karyotypes, which is key in the speciation models of hybrid dysfunction. [ABSTRACT FROM AUTHOR]

Carex section Junciformes is one of the most diverse groups of the genus in South America, consisting of approximately 30 species. Here we describe a new species, Carex recondita, belonging to this section. We studied its placement within a molecular phylogeny of the group and found it to constitute an independent lineage. The new species is morphologically very close to C. austroamericana, from southern Patagonia, despite being phylogenetically divergent to the rest of Patagonian species of sect. Junciformes. So far, this species is known only from a few specimens recently collected in its type locality, despite growing in a well-collected area in the Andes of Metropolitana Region of Santiago, the most populated administrative region of Chile. We provide a detailed morphological description, comments on its relationship with other Southern Cone species of sect. Junciformes and relevant ecological notes. [ABSTRACT FROM AUTHOR]

Exploring the effects of environmental factors and plant physiological processes on plant nutrient stoichiometry is of great significance to understanding how wetland vegetation distributes and maintains function. However, we have a limited understanding of how the combination of plant communities and seasonality with soil physicochemical properties affects nutrient stoichiometry in wetland plants. In this study, we examined these factors in Carex thunbergii and soil across four types of plant communities dominant in the riparian zone of Shengjin Lake during the non−flooding periods of December 2020 and March 2021. In winter, the total foliar C, N, and P concentrations decreased along with an increase in plant coverage, which did not differ in spring. The C, N, C: P, and N: P of foliage significantly increased over the season, while soil C, N, C: P, and N: P significantly decreased over the season. Both in winter and spring, soil C and soil N decreased along with the increase of plant coverage. Our results suggest that both plant community and soil physicochemical properties have a significant influence on plant nutrient stoichiometry. This study improves our understanding of the seasonal dynamics of plant nutrients under different communities and soil physicochemical properties. [ABSTRACT FROM AUTHOR]

Objectives Industry- and occupation-based carcinogen exposure matrices play a pivotal role in preventing occupational cancer. While the Korean CARcinogen EXposure (K-CAREX) has been developed in recent years to assess exposure prevalence and intensity by industry, the feasibility of constructing an occupation-based exposure matrix remains unexplored. Hence, the objective of this study is to explore the potential of combining the nationwide work environment measurement database (WEMD) and the special health examination database (SHED) to develop a comprehensive occupation-based exposure matrix. Methods The WEMD provides information on airborne lead measurements, including industry codes, but it does not include data related to occupations. In contrast, the SHED contains information on both occupation and blood lead levels. By integrating these 2 databases, we attempted to assess airborne lead exposure levels by occupation. Additionally, we performed a rank correlation analysis to compare the airborne exposure levels with corresponding blood lead levels according to occupation. Results A total of 35 425 workers who both wore air samplers for lead and underwent special health examinations for lead were extracted between 2019 and 2021. An occupation-based exposure matrix was developed to evaluate the intensity of lead exposure across a range of occupations, encompassing 51 minor occupations and 70-unit occupations. Rank correlation analyses showed strong positive correlations between airborne lead and blood lead measurements according to occupation. Conclusions Our study findings suggest that combining 2 nationwide surveillance databases can be an effective approach for creating an occupation-based exposure matrix. However, our results also highlight several limitations that need to be addressed in future studies to improve the accuracy and reliability of such matrices. [ABSTRACT FROM AUTHOR]

In Germany, emissions from drained organic soils contributed approximately 53.7 Mio. t of carbon dioxide equivalents (CO2-eq) to the total national greenhouse gas (GHG) emissions in 2021. In addition to restoration measures, shifting management practices, rewetting, or using peatlands for paludiculture is expected to significantly reduce GHG emissions. The effects of climate change on these mitigation measures remains to be tested. In a 2017 experimental field study on agriculturally used grassland on organic soil, we assessed the effects of rewetting and of predicted climate warming on intensive grassland and on extensively managed sedge grassland (transplanted Carex acutiformis monoliths). The testing conditions of the two grassland types included drained versus rewetted conditions (annual mean water table of − 0.13 m below soil surface), ambient versus warming conditions (annual mean air temperature increase of + 0.8 to 1.3 °C; use of open top chambers), and the combination of rewetting and warming. We measured net ecosystem exchange of CO2, methane and nitrous oxide using the closed dynamic and static chamber method. Here, we report the results on the initial year of GHG measurements after transplanting adult Carex soil monoliths, including the controlled increase in water level and temperature. We observed higher N2O emissions than anticipated in all treatments. This was especially unexpected for the rewetted intensive grasslands and the Carex treatments, but largely attributable to the onset of rewetting coinciding with freeze–thaw cycles. However, this does not affect the overall outcomes on mitigation and adaptation trends. We found that warmer conditions increased total GHG emissions of the drained intensive grassland system from 48.4 to 66.9 t CO2-eq ha−1 year−1. The shift in grassland management towards Carex paludiculture resulted in the largest GHG reduction, producing a net cooling effect with an uptake of 11.1 t CO2-eq ha−1 year−1. Surprisingly, we found that this strong sink could be maintained under the simulated warming conditions ensuing an emission reduction potential of − 80 t CO2-eq ha−1 year−1. We emphasize that the results reflect a single initial measurement year and do not imply the permanence of the observed GHG sink function over time. Our findings affirm that rewetted peatlands with adapted plant species could sustain GHG mitigation and potentially promote ecosystem resilience, even under climate warming. In a warmer world, adaptation measures for organic soils should therefore include a change in management towards paludiculture. Multi-year studies are needed to support the findings of our one-year experiment. In general, the timing of rewetting should be considered carefully in mitigation measures. [ABSTRACT FROM AUTHOR]

Global change projections predict more recurrent and intense drought events that along with their legacy effects have potentially long-term impacts on wetland ecosystem structure and function. Carex schmidtii tussocks in wetlands can form different microtopographies that maintain biodiversity and ecological balance. However, how these abiotic factors and their interactions drive C. schmidtii tussock wetland community dynamics and post-drought recovery are still unclear. Therefore, we selected three C. schmidtii tussock wetland types (drought, drought-rewetting, wetting) in the Momoge National Nature Reserve for further investigation. We combined relative importance value, alpha diversity, community similarity and productivity to explore drought and microtopography effects on plant community structure and function. Drought reduced biomass and C. schmidtii dominance, but increased richness and diversity. The degree of C. schmidtii dominance and community biomass was similar to those in the wetting wetland after drought-rewetting, but similarity was low. Plant diversity on tussock hummocks was lower than in hummock interspaces. Lower plant diversity was favorable for biomass accumulation among hummocks and in the overall community, but an opposite trend was found between hummock interspaces. Under drought, loss of C. schmidtii dominance and its biomass proportion resulted in lower hummock biomass, plant diversity, and richness compared to hummock interspaces. Furthermore, there would be significant differences in drought effects on plant similarity across the different microtopographies. Compared to hummock interspaces, hummock community structure was more similar to the overall community, was more susceptible to drought, and did not readily recover. Therefore, in restoration practice, C. schmidtii and hummock community structure should preferentially be restored, to ensure wetland recovery and stability. [ABSTRACT FROM AUTHOR]

Carex qingyuanensis, a new species of Cyperaceae from Guangdong Province, China, is described and illustrated. The new species is morphologically similar to Carex peliosanthifolia F. T. Wang & Tang ex P. C. Li, but it can be distinguished by the racemose inflorescence branches appearing single (rarely binate or ternate) (vs. binate or ternate), one (rarely two or three) (vs. 1–3) spiked, male part of linear-cylindrical spikes much longer than the female part (vs. just male part short-cylindrical and slightly longer than female part), style base thickened (vs. not thickened) and perigynium horizontally patent with a short (vs. long and excurved) beak. Phylogenetic analysis, based on the two nuclear DNA regions (ETS 1f and ITS) and three chloroplast DNA regions (matK, ndhF and rps16), suggests that the new species belongs to sect. Siderostictaes.s. of subg. Siderosticta and shows a closer phylogenetic relationship to Carex scaposa C. B. Clarke. [ABSTRACT FROM AUTHOR]

Carex linanensis X.D.Qiu & X.F.Jin, a new species in sect. Mitratae of the sedge family (Cyperaceae) from north-western Zhejiang is described and illustrated. We performed a statistical comparison of the new species with other closely-related species from the same section. Carex linanensis is similar to Carex sachalinensis F.Schmidt, but differs in having leaf blades 1–2 mm wide (vs. 2.5–3.5 mm wide), utricles longer than pistillate glumes, with beak margin smooth (vs. barbate) and peduncles of lateral spikes enclosed in bract sheaths (vs. exserted from bract sheaths). [ABSTRACT FROM AUTHOR]

Carex duanensis Z.C.Lu, Y.F.Lu & X.F.Jin, a new species in limestone areas of Guangxi, China, was discovered and described. The morphology showed that C. duanensis is similar to C. calcicola, but differs in having culms central, leaf blades 3–5.5 mm wide, bracts longer than spikes, utricles 4–5 mm long, shorter, and nutlets abruptly contracted into an erect beak at apex. SEM microphotographs of utricles and nutlets are provided for the new and related species, C. calcicola. [ABSTRACT FROM AUTHOR]

Microsatellites are codominant markers that, due to their high polymorphism, are a common choice for detecting genetic variability in various organisms, including fungi, plants, and animals. However, the process of developing these markers is both costly and time-consuming. As a result, the cross-species amplification has become a more rapid and more affordable alternative in biological studies. The objective of this study was to assess the applicability of 13 SSR markers, originally designed for Carex curvula, in other 14 species belonging to different sections of the genus. All the markers were successfully transferred with a mean of 90.76%, and 100% transferability was reached in two species (C. baldensis and C. rupestris). The lowest transferability was registered in the G165 marker, which did not produce amplification in six species. Together, the microsatellites amplified a total of 183 alleles, ranging from 10 to 19 alleles per locus, with an average of 14.07. The mean number of different alleles ranged from 0.846 to a maximum of 2.077 per locus. No significant departures from the Hardy–Weinberg equilibrium were detected in polymorphic loci. The transferability of the 13 SSR markers proved highly successful in various Carex species, across different clades and sections of the genus. [ABSTRACT FROM AUTHOR]

Livestock activities impact plant rhizomes and roots in the topsoil, particularly in the early stages of spring for a Carex subalpine meadow. Rest–grazing during critical periods can prevent harm to these roots and rhizomes caused by livestock, thereby enhancing the ecological performance of grasslands. In accordance with soil thawing and plant re‐greening, we designated five rest–grazing periods during the spring in a Carex subalpine meadows. The findings demonstrate that the topsoil of 0–10 cm, largely consisting of Carex roots, housed over 70% of root volume and root mass. After the plant had regained its greenery for a certain duration, rest–grazing resulted in higher vertical root length distribution index. With earlier rest–grazing, root growth in deeper soil was promoted, consequently transporting more organic material to the deeper soil. Deferred rest–grazing time has the potential to enhance lateral rooting extent, root resistance to vertical uprooting, and root accumulation in topsoil. It follows that increased root accumulation in the topsoil leads to greater loss of soil nutrients and carbon. Consequently, we recommend rest–grazing prior to soil thawing for Carex subalpine meadows, which encourages Carex root growth and fosters greater biomass accumulation in deeper soils. Avoiding "running for the green" and "trampling tillage" has a positive effect on both productivity and long‐term soil nutrients and carbon pool management in pastures. [ABSTRACT FROM AUTHOR]

The article "Carex hartmaniorum (Cyperaceae), a new species for the Spanish flora" discusses the discovery of a new plant species, Carex hartmaniorum, in Spain. The article provides details about the characteristics of this species and how it differs from similar plants. It also discusses the distribution and ecology of Carex hartmaniorum, as well as its conservation status in Spain. The species is found in wet meadows in the Pyrénées and is currently endangered due to overgrazing. However, the presence of similar populations in France suggests the possibility of migration and conservation efforts. The article includes references and authorship contributions. [Extracted from the article]

Two recent fieldwork expeditions to Peru and Ecuador resulted in the finding of two Carex species (C. hypsipedos and C. sanctae-marthae) previously known from a single collection each, and of uncertain morphological and systematic affinities. We performed phylogenetic analyses using barcode molecular markers and a detailed morphological comparison among the new specimens and the original collections. A BLAST search was used to obtain the preliminary infrageneric affinities of problematic samples. Phylogenetic results confirmed the adscription of these species to two sectional Carex groups: Carex sect. Racemosae (subg. Carex) for C. hypsipedos and Carex sect. Junciformes (subg. Psyllophorae) for C. sanctae-marthae. Morphological revision revealed unique traits in C. hypsipedos, especially geocarpy, here strikingly reported for the first time for the genus Carex. On the other hand, the careful comparison of the new materials of C. sanctae-marthae revealed unequivocal affinities with the type, confirming its identity as this species. Our work illustrated that for the understanding of poorly known groups, such as these two Neotropical Carex, integrative approaches combining basic biosystematics tools are still very necessary: field and herbaria surveys and DNA barcode. [ABSTRACT FROM AUTHOR]

The article presents three newly discovered interspecific hybrids of sedges found in the Czech Republic. The finds of two of them (Carex ×helenae and C. ×ploegii) are the result of authors' field work and subsequent revision of specimens in large institutional Czech herbaria, while the third, C. ×alluvialis, was documented by a herbarium specimen in the BRNU herbarium, collected in 1998. The finds of these wetland hybrid sedges are a supplement to the treatment of the genus Carex for the Flora of the Czech Republic, Vol. 9. For each of the hybrids, a detailed morphological description compiled on the basis of Czech plants is given and the location of the voucher specimens is mentioned. [ABSTRACT FROM AUTHOR]

Carex L. as a super large genus with a high species diversity in the world, 100 species of Carex have been recorded from Guangxi at present. However, the resources of Carex in Guangxi are still unclear, and lack of research and investigation. Based on specimens identification, literature research and field investigation, we systematically cleared up the early researches of Carex in Guangxi, and summerized the research brief histories of Carex taxonomy in Guangxi. The genus Carex in Guangxi with high endemism, we focused on 16 taxa of Carex published based on types collected from Guangxi, verified the accuracy of their type locality, supplement distribution information, and made sure that eight species of Carex endemic to Guangxi. Eight newly recorded species of Carex in Guangxi are reported here, which are C. alopecuroides D. Don, C. chungii Z. P. Wang, C. hirtiutriculata L. K. Dai, C. insignis Boott, C. nubigena D. Don, C. sendaica Franch., C. sociata Boott and C. transversa Boott. The morphological feature diagnosis and voucher specimens for these newly recorded species are provided. We also discussed the species diversity, endemism, geographical distribution, and the potential utilization of Carex in Guangxi. The results provide background data for the subsequent research and sustainable utilization of Carex.

Carex genus contains over 2000 species distributed all around the globe and used for their medicinal and food values. Owing to their traditional and medicinal properties the genus has gained due attention, especially in the last couple of decades which led to the identification of terpenoids, lignans, quinazolinones, phenolic acids, and phenylpropanoids as the major phytochemicals. Besides these several studies reported the therapeutic applications of the extracts and phytochemicals in different experimental conditions. The present review aims to present a comprehensive overview of the present standing of Carex genus that may promote further scientific exploration and their utilization.

Carex vulpina and C. otrubae are closely related and morphologically similar species that hybridize with C. remota. The spontaneous appearance of hybrids can cause difficulties in the taxonomic treatment of this group. Morphological separation of the examined species and hybrids had been tested using discriminant function analysis (DFA). We have also analysed the effect of DNA barcoding on hybrid identification from the perspective of machine learning approach (MLA). Hybrids were investigated in terms of three barcodes sequence (ITS , matK , rbcL) by means of the BLOG and WEKA (MLA). Our results provide the first insights into the morphological and genetic relationships between the studied species and their hybrids. Morphological analysis showed traits useful in the identification of hybrids, i.e. dark brown usually fibrous basal sheaths and a dorsally split beak in Carex remota  ×  C. vulpina (inherited from C. vulpina), distinctly separated spikes, and a long bract in C. otrubae  ×  C. remota (inherited from C. remota). Phylogenetic analysis also indicated a close relationship of Carex remota  ×  C. vulpina with C. vulpina and C. otrubae  ×  C. remota with C. remota. Moreover, we have presented here nomenclatural notes on the hybrids and typified the names Carex × crepinii [ C. otrubae  ×  C. remota ] and Carex × kernii [ Carex remota  ×  C. vulpina ]. [ABSTRACT FROM AUTHOR]

Hydrological fluctuations are key abiotic stresses that influence plant growth and photosynthetic processes of wetland plants. However, the response mechanism of the plant characteristics and photosynthesis of Carex schmidtii, with respect to hydrological fluctuations, are still unclear. Comparative studies of plant size parameters, biomass parameters, and photosynthesis parameters of C. schmidtii under the interactive influence of initial water depth (WD), water-level amplitude (WA), and duration time, were performed. The coupling relationship between any two factors of the plant characteristics of C. schmidtii was also examined. Generally, the results showed that the WD and WA treatments, and the duration time, significantly affected plant size, biomass, and photosynthesis of C. schmidtii. The exception was the effect by the WA on the biomass and the NPQ. Furthermore, the biomass and photosynthesis of C. schmidtii were significantly affected by the interactive effects by WD and WA. The plant size, biomass, and photosynthesis parameters of C. schmidtii first increased and then decreased over time. Larger values of plant size, biomass, and photosynthesis parameters (except for qL and NPQ) were found for the treatment with an initial water depth of 0 cm. As was the situation with WD, the largest values of plant height, chlorophyll content, Fv/Fm, and ΔFv/Fm' were obtained for a water-level amplitude of 0 cm. Furthermore, the chlorophyll content was positively related to the plant size parameters, Fv/Fm, ΔFv/Fm', and qL. Except for qL, ΔFv/Fm' had a significant relationship with all plant factors. Lower water levels and smaller water level changes are more conducive to the growth and photosynthese of C. schmidtii. Plant size, biomass accumulation and photosynthesis of C. schmidtii collectively coped with hydrological fluctuations. The findings have improved understanding of the response of C. schmidtii to hydrological fluctuations. They have thereby provided invaluable information for the restoration, management and conservation of tussock wetlands. [ABSTRACT FROM AUTHOR]

Carex L. as a super large genus with a high species diversity in the world, 100 species of Carex have been recorded from Guangxi at present. However, the resources of Carex in Guangxi are still unclear, and lack of research and investigation. Based on specimens identification, literature research and field investigation, we systematically cleared up the early researches of Carex in Guangxi, and summerized the research brief histories of Carex taxonomy in Guangxi. The genus Carex in Guangxi with high endemism, we focused on 16 taxa of Carex published based on types collected from Guangxi, verified the accuracy of their type locality, supplement distribution information, and made sure that eight species of Carex endemic to Guangxi. Eight newly recorded species of Carex in Guangxi are reported here, which are C. alopecuroides D. Don, C. chungii Z. P. Wang, C. hirtiutriculata L. K. Dai, C. insignis Boott, C. nubigena D. Don, C. sendaica Franch., C. sociata Boott and C. transversa Boott. The morphological feature diagnosis and voucher specimens for these newly recorded species are provided. We also discussed the species diversity, endemism, geographical distribution, and the potential utilization of Carex in Guangxi. The results provide background data for the subsequent research and sustainable utilization of Carex. [ABSTRACT FROM AUTHOR]

Summary: We present relevant records of nine species of sedges (Cyperaceae) for Peru. For the genus Carex, we present two new national records (C. haematopus, C. lepida), plus relevant data for another six hitherto poorly known species. We also present the first record of Trichophorum rigidum subsp. ecuadoriense for Peru. [ABSTRACT FROM AUTHOR]

Over recent decades, there has been a severe nitrogen-deposition in alpine meadows which often leads to phosphorus limitation of plant productivity. In these high-altitude localities, Cyperaceae have an increasing biomass while other functional groups decrease. Meanwhile, Cyperaceae are known to have the ability of producing dauciform roots, which are formed under phosphorus limitation, but in China, are only described in these high-altitude places. So, is the superiority of Cyperaceae and the formation of dauciform roots in high-altitude localities related to the accumulation of nitrogen? And is there a link between them? A Carex filispica dominated community in Baima Snow Mountain was selected and quantitative fertilization with four levels of nitrogen and three levels of phosphorus was performed. After 2 weeks, Carex filispica individuals with and without dauciform roots were separated and analyzed for their regular root properties, dauciform root properties, biomass and chemical traits of above- and belowground parts. The total cover of the community declined under phosphorus limitation with increasing nitrogen supply, while the relative cover difference of Carex filispica increased with increasing nitrogen supply and decreased with increasing phosphorus supply. Dauciform roots had a more significant response to nitrogen supply than to phosphorus supply and they were formed the most at a low supply of nitrogen. The biomass and root properties of individuals with dauciform roots were enhanced by nitrogen supply and inhibited by phosphorus supply, while those of individuals without dauciform roots were often enhanced by phosphorus supply. Individuals with and without dauciform roots showed two different mechanisms, and were limited by significantly different factors, which can explain the opposite performance of Cyperaceae after nitrogen and phosphorus supply in previous studies. [ABSTRACT FROM AUTHOR]

Background and aims: Special root structures that can dissolve insoluble phosphorus locked in soil are supposed to contribute not only to the growing status of themselves but also to the neighbouring plants. However, whether dauciform roots have any effect on the neighbouring plants and how does it respond to meadow degradation had not been studied. Methods: Alpine meadows with different degradation statuses were selected and the functional traits of Carex filispica and the co-occurring species Polygonum viviparum were measured to explore their response to degradation, as well as the response of Polygonum viviparum to the dauciform roots of Carex filispica. Results: The results showed that 1) the number of dauciform roots decreased with the intensifying degradation, positively related to available phosphorus in the soil and negatively related to the aboveground phosphorus of Carex filispica. 2) Carex filispica and Polygonum viviparum are similar in specific leaf area and specific root area, yet different in the phosphorus content. The available phosphorus in the soil was negatively related to the aboveground phosphorus of Carex filispica and positively related to that of Polygonum viviparum. 3) When lightly degraded, the proportion of dauciform roots had positive effects on the aboveground resource-acquiring traits of Polygonum viviparum, which were no longer significant at heavy degradation. 4) Polygonum viviparum and Carex filispica without dauciform roots have similar performance: a decrease of belowground carbon with the increasing degradation, and a trend toward resource conservation with the increasing proportion of dauciform roots, which did not exist in Carex filispica with dauciform roots. Conclusion: Our study found that dauciform roots had a beneficial effect on the resource acquisition of their neighbouring plants. However, due to the uncontrollable nature of natural habitats, whether this effect is stable and strong enough to be performed in ecological restoration requires further lab- controlled studies. [ABSTRACT FROM AUTHOR]

In the natural habitats of China, dauciform roots were only described in degraded alpine meadows. It was found that the presence of dauciform roots of Carex filispica was related to the advantage of multiple functional traits after trampling, reflecting short‐term resistance. However, the long‐term response of dauciform roots to trampling and the recovery of C. filispica with and without dauciform roots to trampling require further studies. In this study, different intensities of trampling (0, 50, 200 and 500 passages) were performed in an alpine meadow. One year later, individuals with and without dauciform roots were separated and their functional traits related to the economic spectrum of leaves and roots were measured as a reflection of recovery from trampling. The results showed that: (1) 1 year after trampling, the number of dauciform roots showed an increase with trampling intensity; (2) 1 year later, there was no significant difference in the response of economic spectrum traits among trampling intensities, or between plants with and without dauciform roots; (3) the number of dauciform roots was positively correlated with the leaf area of both individuals with and without dauciform roots, as well as with the biomass of those without dauciform roots; and (4) plants with more resource‐conservative roots showed an advantage after trampling recovery: specifically, plants with dauciform roots showed such an advantage in the control group, which was lost with a leaning towards resource‐acquisitive roots and an increased density of dauciform roots once trampled. In contrast, plants without dauciform roots showed a significant advantage of conservative roots only after trampling. In conclusion, the presence of dauciform roots is related to the plants' position on the root economic spectrum, thereby influencing the recovery of C. filispica from trampling. Carex filispica showed strong recovery from trampling after 1 year, which makes it an adequate choice for ecological restoration in alpine meadows. Dauciform roots showed a positive correlation with the aboveground growth of both plants with and without them, however, it requires a lab‐controlled study to confirm whether there is indeed a positive effect on the growth of neighbouring plants. [ABSTRACT FROM AUTHOR]

This study is the first to report the characterization of Carex pumila genomic information. Assembly of the genome generated a draft of C. pumila based on PacBio Sequel II and Illumina paired-end sequencing, which was assembled from 2941 contigs with an estimated genome size of 0.346 Gb. The estimate of repeats in the genome was 31.0%, and heterozygosity ranged from 0.426 to 0.441%. The integrity evaluation of the assembly revealed 1481 complete benchmarked universal single-copy orthologs (BUSCO) (91.76%), indicating the high quality of the draft assembly. A total of 23,402 protein-coding genes were successfully predicted and annotated in the protein database. UpsetR plots showed that 7481 orthogroups were shared by all species. The phylogenetic tree showed that C. pumila is a close but distant relative of Ananas comosus. C. pumila had greater contraction (3154) than expansion (392). Among the extended gene families, aquaporins have been found to be enriched. Primers for microsatellite markers determined 30 polymorphic markers out of 100. The average number of alleles amplified by these 30 polymorphic markers was 4 to 12, with an average polymorphism information content (PIC) value of 0.660. In conclusion, our study provides a useful resource for comparative genomics, phylogeny, and future population studies of C. pumila. [ABSTRACT FROM AUTHOR]

Lectotypes are designated for two Carex buekii hybrid names. The typification is supplemented with notes on their morphology, ecology, and distribution. [ABSTRACT FROM AUTHOR]

Geographic isolation and chromosome evolution are two of the major drivers of diversification in eukaryotes in general, and specifically, in plants. On one hand, range shifts induced by Pleistocene glacial oscillations deeply shaped the evolutionary trajectories of species in the Northern Hemisphere. On the other hand, karyotype variability within species or species complexes may have adaptive potential as different karyotypes may represent different recombination rates and linkage groups that may be associated with locally adapted genes or supergenes. Organisms with holocentric chromosomes are ideal to study the link between local adaptation and chromosome evolution, due to their high cytogenetic variability, especially when it seems to be related to environmental variation. Here, we integrate the study of the phylogeography, chromosomal evolution and ecological requirements of a plant species complex distributed in the Western Euro‐Mediterranean region (Carex gr. laevigata, Cyperaceae). We aim to clarify the relative influence of these factors on population differentiation and ultimately on speciation. We obtained a well‐resolved RADseq phylogeny that sheds light on the phylogeographic patterns of molecular and chromosome number variation, which are compatible with south‐to‐north postglacial migration. In addition, landscape genomics analyses identified candidate loci for local adaptation, and also strong significant associations between the karyotype and the environment. We conclude that karyotype distribution in C. gr. laevigata has been constrained by both range shift dynamics and local adaptation. Our study demonstrates that chromosome evolution may be responsible, at least partially, for microevolutionary patterns of population differentiation and adaptation in Carex. [ABSTRACT FROM AUTHOR]

The knowledge of the genus Carex L. (Cyperaceae) in South America is scattered, without recent comprehensive treatments for any country. Within the continent, Chile is the country that harbors the most diversity, being the second in species richness and the first in endemic taxa. However, Chilean botanists must resort to several Argentinian floras for species identification, although these works leave uncovered many Chilean species. This has led many researchers and amateurs to neglect the amazing diversity of the genus in the country. In this work, we summarize the results of several years of research on the genus Carex in Chile. We here formally report six new national records, including the reinstatement of the Nahuelbuta endemism Carex reicheana Boeckeler. Also, relevant changes (regional additions or significant distributional changes) are reported for another 33 species, and nomenclatural comments on problematic names are given. The catalogue of Carex for Chile is updated with our own findings and previous published reports from 82 to 96 species.

Geometric morphometrics (GM) is a powerful analytical tool that enables complete quantification of shapes. Its use in Botany has a great potential for complementing plant evolutionary and ecological studies. Taxonomic delimitation in Carex has been complicated due to reduction of characters and frequent homoplasy. This problem is more marked in cases where the species exhibit dwarfism. South America is the continent with the least understood Carex flora. The systematic relationships of some bizarre-looking groups were not unraveled until molecular phylogenetic studies resolved their relationships. In particular, there are two species only known from their type material whose affinities remain uncertain: Carex herteri and C. hypsipedos. These two taxa are acaulescent plants that respectively grow in the Uruguayan pampa and Peruvian high-altitude meadows. Recently, both species were ascribed to the Carex phalaroides group (subgen. Psyllophorae, sect. Junciformes) due to superficial morphological similarities, such as the androgynous peduncled spikes. However, their character combination is also coincident for its circumscription to sect. Abditispicae species. Nevertheless, in the absence of confirmation from molecular analyses, their placement must be considered preliminary until additional data can be provided. In this work we employ for the first time geometric morphometrics (GM) tools to assess the systematic affinities of two taxonomically problematic sedge species based on fruit shape. We compared utricle morphology of C. herteri and C. hypsipedos with that of C. phalaroides group and species in sect. Abditispicae. To this end we used GM and traditional morphometric approaches. Utricle shape variation along with other morphological features support the exclusion of these two species from the C. phalaroides gr. and, at the same time, show clear affinities of C. herteri to sect. Abditispicae. Carex hypsipedos remains as an incertae sedis species. Our work shows the potential utility of GM for the exploration of systematic affinities in sedges and in other graminoids. [ABSTRACT FROM AUTHOR]

Main conclusion: The first complete mitochondrial genome of Carex (C. breviculmis) was sequenced and assembled, and its genomic signature was analyzed and the possible conformations of its mitochondrial genome were validated. Carex breviculmis is a very adaptable grass that is highly resistant to environmental stresses such as drought and low light. It is also admired as a landscape plant with high development prospects and scientific research value. In this study, the mitochondrial genome of C. breviculmis was assembled using Pacbio and Illumina sequencing data. We detected 267 pairs of repeats and found that three pairs of repeats could mediate the recombination of its mitochondrial genome and formed four possible conformations, of which we verified the two conformations mediated by the shortest pair of repeats using PCR amplification and Sanger sequencing. The major conformation of the C. breviculmis mitochondrial genome is a 1,414,795 bp long circular molecule with 33 annotated protein-coding genes, 15 tRNA genes, and three rRNA genes. We detected a total of 25 homologous sequences between the chloroplast and mitochondrial genomes, corresponding to 0.40% of the mitochondrial genome. Combined with the low GC content (41.24%), we conclude that the reduction in RNA editing sites in the C. breviculmis mitochondrial genome may be due to an accumulation of point mutations in C-to-T or retroprocessing events within the genome. The relatively low number of RNA editing sites in its mitochondrial genome could serve as important material for subsequent studies on the selection pressure of RNA editing in angiosperms. A maximum likelihood analysis based on 23 conserved mitochondrial genes from 28 species reflects an accurate evolutionary and taxonomic position of C. breviculmis. This research provided us with a comprehensive understanding of the mitochondrial genome of Carex and also provided important information for its molecular breeding. [ABSTRACT FROM AUTHOR]

Holocentric organisms, unlike typical monocentric organisms, have kinetochore activity distributed along almost the whole length of the chromosome. Because of this, chromosome rearrangements through fission and fusion are more likely to become fixed in holocentric species, which may account for the extraordinary rates of chromosome evolution that many holocentric lineages exhibit. Long blocks of genome synteny have been reported in animals with holocentric chromosomes despite high rates of chromosome rearrangements. Nothing is known from plants, however, despite the fact that holocentricity appears to have played a key role in the diversification of one of the largest angiosperm genera, Carex (Cyperaceae). In the current study, we compared genomes of Carex species and a distantly related Cyperaceae species to characterize conserved and rearranged genome regions. Our analyses span divergence times ranging between 2 and 50 million years. We also compared a C. scoparia chromosome‐level genome assembly with a linkage map of the same species to study rearrangements at a population level and suppression of recombination patterns. We found longer genome synteny blocks than expected under a null model of random rearrangement breakpoints, even between very distantly related species. We also found repetitive DNA to be non‐randomly associated with holocentromeres and rearranged regions of the genome. The evidence of conserved synteny in sedges despite high rates of chromosome fission and fusion suggests that conserved genomic hotspots of chromosome evolution related to repetitive DNA shape the evolution of recombination, gene order and crossability in sedges. This finding may help explain why sedges are able to maintain species cohesion even in the face of high interspecific chromosome rearrangements. [ABSTRACT FROM AUTHOR]

Introduction: The drought and phosphorus deficiency have inevitably become environmental issues globally in the future. The analysis of plants functional trait variation and response strategies under the stress of phosphorus deficiency and drought is important to explore their ability to respond to potential ecological stress. Methods: In this study, Carex breviculmis was selected as the research object, and a 14-week pot experiment was conducted in a greenhouse, with two phosphorus treatment (add 0.5mmol/L or 0.05mmol/L phosphorus) and four drought treatment (add 0-5%PEG6000), totaling eight treatments. Biomass allocation characteristics, leaf anatomical characteristics, biochemical parameters, root morphology, chemical element content, and photosynthetic parameters were measured. Results: The results showed that the anatomical characteristics, chemical elements, and photosynthetic parameters of Carex breviculmis responded more significantly to main effect of phosphorus deficiency. Stomatal width, leaf phosphorus content and maximum net photosynthetic rate decreased by 11.38%, 59.39%, 38.18% significantly (p<0.05), while the change in biomass was not significant (p>0.05). Biomass allocation characteristics and root morphology responded more significantly to main effect of drought. Severe drought significantly decreased leaf fresh weight by 61% and increased root shoot ratio by 223.3% compared to the control group (p<0.05). The combined effect of severe drought and phosphorus deficiency produced the highest leaf N/P ratio (291.1% of the control) and MDA concentration (243.6% of the control). Correlation analysis and redundancy analysis showed that the contributions of phosphorus and drought to functional trait variation were similar. Lower epidermal cell thickness was positively correlated with maximum net photosynthetic rate, leaf phosphorus, chlorophyll ab, and leaf fresh weight (p<0.05). Discussion: In terms of response strategy, Carex breviculmis was affected at the microscopic level under phosphorus deficiency stress, but could maintain the aboveground and underground biomass well through a series of mechanisms. When affected by drought, it adopted the strategy of reducing leaf yield and improving root efficiency to maintain life activities. Carex breviculmis could maintain its traits well under low phosphorus and moderate drought, or better conditions. So it may have good ecological service potential in corresponding areas if promoted. This study also provided a reference for plant response to combined drought and phosphorus deficiency stresses. [ABSTRACT FROM AUTHOR]

Postfloral peduncle laying is regarded as an element of myrmecochorous syndrome, which is presumed to facilitate seed discovery by ants by presenting seeds on the ground. However, this presumption does not explain why the peduncles should lay down rather than dropping diaspores on the ground. In this study, an alternative hypothesis is proposed, the distance hypothesis, stating that peduncle laying extends the primary dispersal distance and thereby enhances myrmecochory or functions as an insurance against myrmecochory failure. To test the distance hypothesis, I focused on several myrmecochorous sedge species. First, the occurrence of postfloral peduncle elongation was examined, which contributes to the extension of primary dispersal distance and is not directly relevant to seed presentation on the ground. The primary dispersal distances relative to sedge canopy radius were quantified to infer the insurance function, that is, the extent to which peduncle laying and elongation alone isolate seedlings from the sedge canopy. The effect of primary dispersal distances on myrmecochory were examined in a field experiment. Postfloral peduncle elongation was observed in all species examined. The insurance function of peduncle laying and elongation was supported in a subset of sedge species, in which primary dispersal distances were approximately twice as long as the sedge canopy radius. The field experiment revealed that longer primary dispersal distances increased both the number of ant nests into which diaspores were transported and myrmecochorous dispersal distances. These results support the distance hypothesis and highlight the need to reconsider the function of peduncle laying in myrmecochores. [ABSTRACT FROM AUTHOR]

Carex species are widely used in many parts of the world and contain a large number of ecologically diverse species. Among the Carex species, some of them are known to be glycophytes, while others are halophytes. Carex morrowii Boott (Cyperaceae) is resistant to trample through their root structure and has an essential ornamental value in the landscape with their leaves. However, no information was found about the level of salinity tolerance/sensitivity of the Carex morrowii among these species. In the present study, changes in trace element contents (Na, K, Ca, Cu, Mn, Mg, Ni, Fe, P, Zn, and N) and their transport from roots to leaves, osmotic regulation, alterations in chlorophyll and carotenoid contents, nitrogen assimilation (nitrate reductase activity; NRA) and total soluble protein content in both roots and leaves of Carex morrowii under different salinity concentrations (50 mM, 100 mM, 200 mM and 300 mM NaCl) were examined in detail. Our study provides the first detailed data concerning the responses of leaves and roots and the determination of the level of salinity tolerance/sensitivity of the Carex morrowii. The K+/Na+ ratio was preserved up to 200 mM NaCl, and accordingly, the element uptake and transport ratios showed that they could control moderate NaCl levels. Ca homeostasis that is maintained even in 200 mM NaCl concentration can be effective in maintaining the structural integrity and selective permeability of the cell membranes, while 300 mM NaCl concentration caused decreased photosynthetic pigments, and deterioration in element content and compartmentation. Moreover, these data suggest that plant parts of Carex morrowii respond differently against varied levels of salinity stress. Although the decrease in NR activity at 200 mM and 300 mM NaCl concentrations in the leaves, NR activity was maintained in the roots. Consequently, Carex morrowii is moderately tolerant to salinity and the carotenoid content and osmotic regulation of Carex morrowii appears to be instrumental in its survival at different salinity levels. Especially the roots of Carex morrowii have a remarkable role in salinity tolerance. [ABSTRACT FROM AUTHOR]

Carex heterostachya and Carex breviculmis are easy to develop lawns in a short period while taking on high ornamental significance in northwest China where summer temperatures are high, rainfall is uneven, and soil is scarce. Several questions were raised, which are elucidated as follows: what type of plant functional characteristic has they formed for long-term survival and adaptation to this environment; which plant is more adaptable; which leaf functional characteristic are critical to photosynthetic characteristics. The following conclusions were drawn based on the exploration of the leaf functional characteristic of the two plants using gas exchange technology and field emission electron scanning technology: (a) C. breviculmis refers to a slow investment-return plant, exhibiting strong environmental adaptability and plasticity, and it is resistant to barrenness, drought, and shade. C. heterostachya refers to a type of quick investment-return plant, with high photosynthetic efficiency, well-developed transport tissue, and relatively shade-tolerant. The soil with low water content and poorer soil applies to C. breviculmis cultivation, and C. heterostachya applies to cultivation in the environment with sufficient light and rich nutrients. Moreover, C. breviculmis and C. heterostachya can be adopted to enrich the diversity of understory landscape. (b) Carex exhibits strong environmental adaptability, large variation in eco-physiological characteristics, as well as strong plasticity. Leaf anatomical characteristics are stable, whereas differences exist in the interspecific variability and plasticity. (c) when the genus Carex grew in the semi-shade and the soil environment was arid, specific leaf area (SLA) can become the main factor for the photosynthetic availability of Carex, the thickness of the stratum corneum, the thickness of the upper serve as secondary factors. The above-described findings can lay a theoretical basis for the cultivation and application of Carex and the expansion of turfgrass germplasm resources. [ABSTRACT FROM AUTHOR]