Nymphoides Peltata Research Articles

Native and invaded-range surveys provide mixed support for enemy-release of Nymphoides peltata in the invaded range

Natural or anthropogenic movement of plant species outside their historical ranges may result in exposure to new environmental conditions and a lack of natural enemies, thus promoting their establishment and spread into new areas. A biogeographical comparison of native and invasive populations can provide insight into the mechanisms of successful invasions and guide effective management strategies, such as biological control, by targeting plant traits that promote invasiveness. We studied the Eurasian aquatic plant, Nymphoides peltata, in situ in the native (China, Korea) and invaded (USA) ranges to determine whether there were differences in natural enemy attack rates (percent leaf damage, frequency of leaf herbivory or disease), productivity (plant cover, reproduction), and leaf traits (leaf elemental content, leaf toughness, dry matter content, specific leaf area) between areas. We also investigated whether there was evidence of a tradeoff between natural enemy attack and growth or reproduction, as would be predicted by invasion theory. Plant cover (23–29 % higher) and reproductive output (eight times more seeds / m2) were consistently higher in the invaded range. Leaf traits consistently differed between ranges, which we would expect if plants in the invaded range had fewer herbivores or other pests. The amount of leaf damage present was similar between ranges, but the frequency of herbivory was 50 % greater, on average, in the native than invaded range. Although we did not quantify suppression of N. peltata by natural enemies, we found evidence of more frequent herbivory in Asia and reduced reproduction and plant cover compared to the USA, which supports further investigation into viability of biological controls.

Ecological and functional niches comparison reveals differentiated resource‐use strategies and ecological thresholds in four key floating‐leaved macrophytes

AbstractNiche theory has been widely used in ecology; however, few studies have attempted to combine information on functional and ecological niches (i.e., variation in traits and environmental requirements), especially for freshwater macrophytes. In this study, we aim to describe the functional and ecological niches of four key nymphaeid species (Nuphar lutea, Nymphaea alba, Nelumbo nucifera, and Nymphoides peltata) to investigate their environmental tolerance and functional adaptability. Twelve Italian populations per species were sampled. Functional and ecological niches were determined using hypervolumes based on eight functional traits and environmental variables, related to leaf structure and economics spectrum, and to water and sediment quality. Among the three Italian native species, N. lutea and N. alba showed intermediate niche size and position in the functional and ecological space, although N. alba appears to be less competitive due to a small functional niche and lower trait performance, which could explain its general tendency to decline. N. peltata appeared more specialized in its environmental requirements and characterized by highly acquisitive leaves, while the invasive alien N. nucifera exerted its competitive success by distinguishing its functional niche and expanding its ecological niche, through high investment of resources in leaves. Overall, all four target species share similar ecological niches, colonizing eutrophic ecosystems typical of intensive agricultural landscapes, but show different patterns in their functional niche. We demonstrate the applicability of an approach based on both functional and ecological niches to unravel species' adaptation and strategies.

Impact of Environmental Food Intake on the Gut Microbiota of Endangered Père David's Deer: Primary Evidence for Population Reintroduction.

Reintroduction has been successful in re-establishing several endangered wild animals in their historical habitats, including Père David's deer (Elaphurus davidianus). Continuous monitoring of reintroduced individuals is essential for improving the sustainability of ex situ conservation efforts. Despite an increased recognition of the significance of the gut microbiome for animal health, the correlation between diet and the gut microbiome in E. davidianus is unclear. In this study, 15 fresh fecal samples of E. davidianus were collected from Tianjin Qilihai Wetland and the association between dietary and gut microbiota composition was evaluated. Microscopic observations showed that Nymphoides peltata [relative density (RD = 0.3514), Phragmites australis (RD = 0.2662), Setaria viridis (RD = 0.1211), and Typha orientalis (RD = 0.1085) were the main dietary plants in the fecal samples. High-throughput 16S rRNA sequencing showed a predominance of the phyla Firmicutes and Proteobacteria and the genus Psychrobacillus (26.53%) in the gut microbiota. The RD of N. peltata was significantly positively correlated with the abundance of Firmicutes (p = 0.005) and the genus UCG-005 (p = 0.024). This study indicates a close association between food digestion and nutrient intake, providing basic monitoring data for the full reintroduction and recovery of wild E. davidianus.

Iridoid Glycosides and Coumarin Glycoside Derivatives from the Roots of Nymphoides peltata and Their In Vitro Wound Healing Properties.

Nymphoides peltata has been used as a medicinal herb in traditional medicines to treat strangury, polyuria, and swelling. The phytochemical investigation of the MeOH extract of N. peltata roots led to the isolation of three iridoid glycosides and three coumarin glycoside derivatives, which were characterized as menthiafolin (1), threoninosecologanin (2), callicoside C (3), and scopolin (4), as well as two undescribed peltatamarins A (5) and B (6). The chemical structures of the undescribed compounds were determined by analyzing their 1 dimensional (D) and 2D nuclear magnetic resonance (NMR) spectra and using high-resolution (HR)-electrospray ionization mass spectroscopy (ESI-MS), along with the chemical reaction of acid hydrolysis. The wound healing activities of the isolated compounds 1-6 were evaluated using a HaCaT cell scratch test. Among the isolates, scopolin (4) and peltatamarin A (5) promoted HaCaT cell migration over scratch wounds, and compound 5 was the most effective. Furthermore, compound 5 significantly promoted cell migration without adversely affecting cell proliferation, even when treated at a high dose (100 μM). Our results demonstrate that peltatamarin A (5), isolated from N. peltata roots, has the potential for wound healing effects.

The content of chemical elements in <i>Trаpa nаtans</i> and <i>Nymphoides peltata</i> of the Volga Delta

Aim. To identify the specific features of the accumulation of heavy metals in Trаpa nаtans and Nymphoides peltata in the Volga delta. Materials and Methods. Plant sampling was carried out in the Astrakhan State Nature Biosphere Reserve. Determination of the concentration of chemical elements was carried out using atomic absorption spectrophotometry. Results. As a result of the research it was noted that the plant species studied had some similarities in the accumulation of chemical elements. In both types of plants iron was predominantly accumulated, manganese content being in second place in terms of metal concentration. Chromium and cadmium were found to be in the lowest concentrations. Nymphoides peltata is an iron accumulator compared to Trapa natans. The leaves of Trapa natans are manganese concentrators, while the stems are copper concentrators. Conclusions. Based on the specific features identified in the accumulation of chemical elements in plants, a proposal is put forward regarding the possibility of using the leaves and stems of Nymphoides peltata as a test object for monitoring iron and chromium concentrations in water and the leaves of Trapa natans for monitoring copper concentrations in water.

3‴-O-Foliamenthoyl-Rutin, a New Flavonoid Glycoside from the Roots of Nymphoides peltata.

Nymphoides peltata (Menyanthaceae) has been used as a medicinal herb in traditional medicines to treat conditions such as strangury, polyuria, swelling, and as a diuretic and antipyretic. In our ongoing research to discover novel structural and/or biological natural products in natural resources, five flavonoids, quercetin (1), quercitrin (2), isoquercetin (3), quercetin-3-O-vicianoside (4), and rutin (5), as well as a new flavonoid glycoside, 3‴-O-foliamenthoyl-rutin (6), were isolated from the MeOH extract of N. peltata roots. The chemical structure of the new compound (6) was determined by analyzing 1D and 2D NMR spectra and high-resolution (HR) electrospray ionization mass spectroscopy (ESIMS), along with a chemical reaction. The wound-healing activities of the isolated compounds (1-6) were evaluated using a HaCaT cell scratch test. Among the isolates, isoquercetin (3), quercetin-3-O-vicianoside (4), and 3‴-O-foliamenthoyl-rutin (6) promoted HaCaT cell migration over scratch wounds, with compound 4 being the most effective. Our findings provide experimental data supporting the potential of quercetin-3-O-vicianoside (4) as a wound-healing agent.

Anti-Wrinkling Effect of 3,4,5-tri-O-caffeoylquinic Acid from the Roots of Nymphoides peltata through MAPK/AP-1, NF-κB, and Nrf2 Signaling in UVB-Irradiated HaCaT Cells.

Nymphoides peltata has been widely used pharmacologically in traditional Chinese medicine to treat heat strangury and polyuria. The aim of this study was to isolate the bioactive components from N. peltata and evaluate their potential use as antioxidant and anti-wrinkle agents. Phytochemical investigation of the methanolic extract of N. peltata roots led to the isolation of 15 compounds (1-15), which were structurally determined as α-spinasterol (1), 3-O-β-D-glucopyranosyl-oleanolic acid 28-O-β-D-glucuronopyranoside (2), 4-hydroxybenzoic acid (3), protocatechuic acid (4), vanillic acid (5), p-coumaric acid (6), caffeic acid (7), ferulic acid (8), neochlorogenic acid (neo-CQA) (9), chlorogenic acid (CQA) (10), cryptochlorogenic acid (crypto-CQA) (11), isochlorogenic acid B (3,4-DCQA) (12), isochlorogenic acid A (3,5-DCQA) (13), isochlorogenic acid C (4,5-DCQA) (14), and 3,4,5-tri-O-caffeoylquinic acid (TCQA) (15). Of these 15 compounds, compound 2 was a new oleanane saponin, the chemical structure of which was characterized by 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data and high-resolution electrospray ionization mass spectrometry (HRESIMS), as well as chemical reaction. Biological evaluation of the isolated compounds revealed that 3,4,5-tri-O-caffeoylquinic acid (TCQA) significantly improved Nrf2 levels in an Nrf2-ARE reporter HaCaT cell screening assay. TCQA was found to potently inhibit the Nrf2/HO-1 pathway and to possess strong anti-wrinkle activity by modulating the MAPK/NF-κB/AP-1 signaling pathway and thus inhibiting MMP-1 synthesis in HaCaT cells exposed to UVB. Our results suggest that TCQA isolated from N. peltata might be useful for developing effective antioxidant and anti-wrinkle agents.

Genome-wide SNPs reveal clonality and population genetic structure of Nymphoides peltata in Japan (Menyanthaceae)

The clonal diversity of Nymphoides peltata in Japan was estimated using genome-wide SNPs. In total, 27 clones were detected by considering the genetic distances between clones. The number of clones was much smaller than the estimate of 61 from a previous study that used SSR (Short Sequence Repeats) markers. This may be because population have diminished due to environmental deterioration over the past decade, fewer samples were analyzed in this study, or there were technical problems with the SSR markers used in the previous study. The populations of N. peltata were genetically differentiated between the western and eastern regions of the Japanese archipelago. Artificial movements may have occurred in a few populations.

<i>NYMPOIDES PELTATA</i> (MENYANTHACEAE) – A NEW SPECIES FOR THE FLORA OF LENINGRAD REGION

The article presents data on the locality of Nymphoides peltata (S.G. Gmel.) Kuntze, a new species for the flora of the Leningrad Region. A rare alien species forms extensive thickets on Lake Nakhimovskoye (Vyborgsky District).

Identification for the species of aquatic higher plants in the Taihu Lake basin based on hyperspectral remote sensing.

Aquatic plants are crucial for aquatic ecosystems and their species and distribution reflect aquatic ecosystem health. Remote sensing technology has been used to monitor plant distributions over large scales. However, the fine identification of the species of aquatic higher plants is challenging due to large temporal-spatial changes in optical water body properties and small spectral differences among plant species. Here, an aquatic plant identification method was developed by constructing a decision tree file in the C4.5 algorithm based on the canopy spectra of eight plants in the Changguangxi Wetland water area from hyperspectral remote sensing technology. The method was used to monitor the distribution of different plants in the Changguangxi Wetland area and two other water areas. The results showed that the spectral characteristics of plants were enhanced by calculating their spectral index, thereby improving the comparability among different species. The total recognition accuracy of the constructed decision tree file for eight types of plants was 85.02%. Nymphaea tetragona, Pontederia cordata, and Nymphoides peltatum had the highest recognition accuracy and Eichhornia crassipes was the lowest. The specific species and distributions of aquatic plants were consistent with the water quality in the area. The results can provide a reference for the accurate identification of aquatic plants in the same type of water area.

Nymphoides peltata Root Extracts Improve Atopic Dermatitis by Regulating Skin Inflammatory and Anti-Oxidative Enzymes in 2,4-Dinitrochlorobenzene (DNCB)-Induced SKH-1 Hairless Mice.

Nymphoides peltata is widely used pharmacologically in Traditional Chinese Medicine and Ayurvedic medicine as a diuretic, antipyretic, or choleretic and to treat ulcers, snakebites, and edema. Previous studies have shown that phytochemicals from N. peltata have physiological activities such as anti-inflammatory, anti-tumor, and anti-wrinkle properties. Nevertheless, research on the anti-atopic dermatitis (AD) effect of N. peltata extract is limited. This study was undertaken to assess the in vitro and in vivo anti-atopic and antioxidant activities of a 95% EtOH extract of N. peltata roots (NPR). PI-induced RBL-2H3 cells and two typical hapten mice (oxazolone-induced BALB/c mice and 2,4-dinitrochlorobenzene (DNCB)-induced SKH-1 hairless mice) were used to investigate the effect of NPR extract on AD. The expressions of AD-related inflammatory cytokines, skin-related genes, and antioxidant enzymes were analyzed by ELISA, immunoblotting, and immunofluorescence, and skin hydration was measured using Aquaflux AF103 and SKIN-O-MAT instruments. The chemical composition of NPR extract was analyzed using an HPLC-PDA system. In this study, NPR extracts were shown to most efficiently inhibit IL-4 in PI-induced RBL-2H3 cells and AD-like skin symptoms in oxazolone-BALB/c mice compared to its whole and aerial extracts. NPR extract markedly reduced DNCB-induced increases in mast cells, epidermal thickness, IL-4 and IgE expressions, and atopic-like symptoms in SKH-1 hairless mice. In addition, NPR extract suppressed DNCB-induced changes in the expressions of skin-related genes and skin hydration and activated the Nrf2/HO-1 pathway. Three phenolic acids (chlorogenic acid, 3,5-dicaffeoylquinic acid, and 3,4-dicaffeoylquinic acid) were identified by HPLC-PDA in NPR extract. The study shows that NPR extract exhibits anti-atopic activities by inhibiting inflammatory and oxidative stress and improving skin barrier functions, and indicates that NPR extract has potential therapeutic use for the prevention and treatment of AD.

Inter-Species and Inter-Organ Differences in Stable C and N Isotope Signatures of Macrophytes from the Largest Freshwater Lake in China

Macrophytes play important roles in shallow aquatic ecosystems. Stable isotope signatures of macrophytes indicate the environmental conditions and macrophyte contributions to food webs. However, macrophyte isotope signatures have been studied less than isotope signatures of other organisms. We determined the stable C and N isotope signatures of 10 aquatic plant species from Poyang Lake wetland (Wucheng, Yongxiu County) and Nanji wetland (Nanjishan, Xinjian County) in Jiangxi Province, which are Chinese national nature reserves, among different seasons. The isotope signatures for different species and seasons were significantly different. The dominant macrophyte species were Potamogeton malaianus and Nymphoides peltatum. The isotope signatures for different organs of these two species were determined. Both δ13C and δ15N values were higher for P. malaianus than for N. peltatum stems, roots and leaves, and δ13C varied less for N. peltatum than for P. malaianus organs. The δ13C and δ15N values for P. malaianus organs increased in the order roots<stems<leaves. δ13C values for N. peltatum organs decreased in the order roots>stems>leaves, and δ15N values for N. peltatum organs increased in the order roots<stems<leaves. The stable C and N isotope signatures for P. malaianus and N. peltatum may be controlled by various factors including macrophyte life history, external sources of C/N, and the amount of water in the wetland. These results provided a theoretical reference and experimental data support for detecting the flow trend of C & N elements and environment changes in the lake by the δ13C and δ15N values of euhydrophytes.

Response of aquatic plant decomposition to invasive algal organic matter mediated by the co-metabolism effect in eutrophic lakes

The decomposition of aquatic plant residues changes by the invasive algal organic matter in eutrophic lakes, however, the driving mechanisms of these biogeochemistry processes are still far from clear. In this study, a series of microcosms was constructed to simulate the mixed decomposition processes of aquatic plant residues with invasive algae as long as 205 days. Three aquatic plants (Potamogeton malaianus, Nymphoides peltatum, and Phragmites australis) and algae were collected from a typical eutrophic lake. The addition of algae promoted the decomposition of three plant residues based on the mass loss, and the positive co-metabolism effect was produced. The co-metabolism intensity was 8%–25% on the water surface and 19%–45% on the water-sediment interface, respectively. In addition, the response of three aquatic plant residues to the algal organic matter was different with their co-metabolism intensities in the order of P. australis > P. malaianus > N. peltatum on both the water surface and water-sediment interface. The phylum number of bacteria attached to the surface of plant residues increased from 27 to 52. The abundance of Bacteroidetes, which had the function of decomposing refractory organic matter, increased most significantly at the final incubation. At present, shallow lakes are under the double pressure of eutrophication and global warming, and the intensity and duration of algal blooms are increasing. Therefore, the co-metabolism effect of the residue decomposition process described here may change the carbon cycle strength and increase the greenhouse gas emissions of lakes and need to be taken into account in future lake management.

Species evenness affects algae driven co-metabolism with aquatic plant residues

Understanding the mixed decomposition processes of aquatic plant residues is crucial for evaluating the carbon cycle of lakes. However, the complex effect of species evenness, and especially the algae driving co-metabolism effect in eutrophic lakes are still far from clear. In this study, three dominant aquatic plants (Phragmites australis, Nymphoides peltatum, and Potamogeton malaianus) and algae from the typical eutrophic and shallow Lake Taihu, China, were selected to simulate their mixed decomposition process. The addition of algae accelerated the mass loss of cellulose, hemicellulose, and lignin of aquatic plant residues and increased the total mass loss by 2.29~6.32% in mixed decomposition. The positive co-metabolism effect, with the intensity ranging from 10% to 17%, occurred during the mixed decomposition process. In addition, the positive co-metabolism effect was also found among plant residues during mixed decomposition and the co-metabolism intensity of species evenness mixed decomposition was more than twice as high as that of non-evenness mixed decomposition. The addition of algae during the decomposition of aquatic plant residues altered the stoichiometry of available nutrients and affected the microbial decomposition activity. The abundance of decomposition bacteria, especially Bacteroidetes, was increased and the community structure also changed, as evidenced by a 71% increase in the number of bacteria phylum. As a result, these biogeochemistry processes accelerated the decomposition rates of aquatic plant residues and thus produced the positive co-metabolism effect. Therefore, the co-metabolism effects of mixed decomposition described in this study are prevalent in eutrophication lakes and have important effects on the lake carbon cycle, which need to be considered in future lake management.Graphical

『詩經』에 보이는 ‘荇菜’의 한국어 번역 양상 고찰

The Book of Poetry is the beginning and core of Chinese literature. The first poem to appear in the Book of Poetry is「周南·關雎」 and the first plant that appears among them is ‘荇菜’. However, in the introduction book of Chinese literature and the translation of Poetry in Korea, 荇菜 was translated differently into ‘Haengchae grass’, ‘Marum(water caltrop) grass’, ‘Joagi grass’, ‘Marum(water caltrop) leaf’, etc., Therefore, I tried to find the reason why ‘荇菜’ translated differently and discuss which name was correct. In domestic dictionaries, most of the 荇菜 were marked as ‘Marum(water caltrop)’ and the basis for it would be said to be in『詩經諺觧』. Originally, the Marum was not a specific plant name, but a common name of algae plants. However, the modern Korean dictionary clearly defines ‘water caltrop’ and ‘Nymphoides peltata’ as different plants. But, it is still easy to find the interpretation of the 荇菜 as ‘Marum(water caltrop)’ in domestic translations and papers. In plant diagrams and medical books, 荇菜 clearly refers to ‘Nymphoides peltata’ so a clear translation is needed. Since form is important in translating poetry, it may be a way to translate it into ‘Haengchae’ or ‘Eoriyeon’.

Performance and ecological impacts of benthic barriers for the control of an invasive plant in a small urban lake

Yellow Floating Heart (YFH), Nymphoides peltata, is a rooted aquatic plant that is not native to North America, and can quickly establish nuisance populations in shallow lakes, rivers, and wetlands. There are few documented methods for effectively eradiating or controlling YFH. Little Albro Lake is a small (3 ha), shallow (<5 m deep) meso-eutrophic lake in Dartmouth, Nova Scotia, Canada that experiences an annual YFH infestation covering >50% of the lake during the growing season. A pilot study was conducted during the 2021 growing season to: (i) assess the feasibility of using benthic barriers to control YFH growth, and (ii) investigate the potential impacts of benthic barriers on ecosystem components. Two commercially available benthic barriers (Aquascreen, a permeable barrier, and Lake Bottom Blanket, an impermeable barrier) were tested in shallow (1 m water depth) and deep (3 m water depth) areas of the lake. A total of 18 test plots (6 permeable, 6 impermeable, 6 control), each measuring 3 m × 3 m, were established in early May 2021, and monitored throughout the growing season (May–September). Both types of barriers were effective in reducing YFH growth, with barriered plots possessing significantly less YFH coverage than control plots. Inspection of the permeable barriers after their removal from the lake, however, revealed that YFH had been able to grow through this type of barrier material. Several maintenance issues were also noted with both barriers including: (i) gas build-up under the barriers, which caused billowing, and (ii) an accumulation of sediment on top of the barriers and growth of YFH through these sediment layers. Both issues would need to be managed during a full-scale benthic barrier application program. An environmental effects monitoring program was also undertaken to understand the lake ecosystem and impacts of the barriers on the chemical and biological properties of the lakebed. The barriers had measurable impacts on the lakebed and generated lower oxidation reduction potential (ORP) in sediments, as compared to control plots with no barriers. Reduced ORP in lake sediments could facilitate the mobilization of redox-sensitive metals, such as arsenic and iron. There were only minor differences in benthic macroinvertebrate populations when comparing barriered and control plots. The bacterial alpha-diversity of the lakebed sediment was shown to differ by depth, with the shallow zone having higher observed ASVs and diversity levels. However, within the two depth zones, the barriers did not appear to have a large impact on bacterial community composition and potential functionality. In conclusion, benthic barriers can be used to prevent YFH growth, however barrier installations require maintenance and may reduce sediment ORP, potentially leading to release of redox-sensitive metals and nutrients.

Plant traits and environment: floating leaf blade production and turnover of Nymphoides peltata (S.G. Gmel.) O. Kuntze (Menyanthaceae).

BackgroundNymphaeid macrophytes, rooting in the sediment of water bodies and characterized by floating leaves, play an important role in wetland ecosystems. The present research deals with the effects of limited space, limited nutrient availability, water temperature and an unexpected inundation on the production, turnover and plasticity of floating leaves of the globally widespread species Nymphoides peltata (Fringed waterlily).MethodsThe effects of these environmental conditions were studied in two plots in outdoor concrete tanks (CT1, CT2, mesocosms simulating occurrence in small ponds) and in two plots in the floodplain oxbow lake Bemmelse Strang (BS1, BS2). Plot CT1 was situated in a stand coexisting with helophytes, plot CT2 in a monospecific stand, plot BS1 in the center and plot BS2 at the open water border of a monospecific stand. All floating leaf blades within the plots were marked at appearance at the water surface and subsequently length, width and damage of each leaf and maximum and minimum water temperatures were measured bi-weekly. Area and biomass of leaf blades were calculated based on leaf length and width and were used to calculate turnover rates and production.ResultsThe growth period started in May and ended mid-October with continuous production of floating leaves during nearly the whole vegetation period. In the tanks the water level was very stable, but the lake underwent an inundation by river water, causing a sudden loss of existing leaves. Considering environmental conditions and based on the assumed ranking from low to high nutrient availability, the ranking of the plots was CT1, CT2, BS1, BS2. This order was found for maximum leaf life span and maximum leaf length, and the reverse order was found for number of leaves, new leaves per day and duration of the vegetation period. Turnover rates appeared to be relatively similar for plots CT1, CT2 and BS1, but for the deeper border plot BS2 lower ratios were found. These results indicate that increased enclosure with expected nutrient limitation causes (1) the production of high numbers of small leaves with larger totals for leaf area and biomass, (2) a shift towards increased sexual reproduction by the production of more flowering stem leaves.

The complete chloroplast genome sequence of Nymphoides peltata (S.G.Gmel.) Kuntze

Nymphoides peltata is an aquatic floating weed widely distributed in the northern hemisphere of Eurasia. To better determine its phylogenetic relationships with other Nymphoides species and other aquatic plant species, the chloroplast genome of N. peltata was sequenced. The chloroplast genome size is 152,198 bp, consisting of a large single-copy region (84,223 bp) and a small single-copy region (17,817 bp) separated by a pair of inverted repeats with a length of 25,079 bp. The chloroplast genome contains 127 genes, including 85 protein-coding genes, 34 tRNA genes, and eight rRNAs. The maximum-likelihood phylogenetic tree showed that N. peltata is more closely related to other Nymphoides species, providing new insight into the evolution and genetic diversity of aquatic weeds.

Understanding the ecological processes governing hydrophyte-associated bacterial communities involved in hydrophyte growth and development

Maintaining hydrophyte growth has been a major focus of aquatic ecological research. The hydrophyte microbiome plays a key role in the growth and health of hydrophytes, but the ecological processes regulating the assembly and function of hydrophyte microbial communities remain unclear. This knowledge gap limits the efficacy of managing microbiomes to enhance the capacity of hydrophytes to restore the aquatic environment. Here, we sampled three typical hydrophytes (Ceratophyllum demersum, Nymphoides peltatum, and Potamogeton crispus) to study the ecological process governing hydrophyte-associated bacterial communities. The results demonstrated that hydrophyte-associated bacterial communities were affected more by the hydrophyte host species (HEEI = 2.40) than by the environment (HEEI = 1.00). The hydrophyte host species not only affected bacterial community assembly, but reduced the diversity and network complexity of the bacterial community relative to that of the environment. Furthermore, the core taxa of two hydrophytes were identified. Chryseobacterium was the core taxon of N. peltatum, and Burkholderia-Caballeronia-Paraburkholderia, Pseudolabrys, and Pajaroellobacter were the core taxa of P. crispus. The core taxa of P. crispus were closely related to potential denitrification-related functions of bacteria and revealed that P. crispus played a role in denitrification during aquatic ecological restoration. Overall, the results of this study highlight the need to develop approaches employing hydrophyte-associated bacteria to promote the development of hydrophytes, which will be essential for increasing the utility of hydrophyte microbiomes in the future and enhancing aquatic ecological restoration.

Notes on the taxonomy of Nymphaeaceae and Menyanthaceae in Mongolia

In this study, we investigated four aquatic plants, namely Nuphar pumila (Timm) DC. and Nymphaea candida C.Presl in Nympaeaceae as well as Menyanthes trifoliata L. and Nymphoides peltata (S.G. Gmel.) Kuntze in Menyanthaceae from Mongolia based on field surveys, herbariums, and scientific literature. In addition, we carefully examined for Nymphaea tetragona Georgi, which was previously recorded in several lakes, Khar-Us, Khar, Buuntsagaan, and Tsetsegt as well as the Ider river in Mongolia. Because we did not find N. tetragona in the field and because it is difficult to identify from herbarium specimens, we believe it has been misidentified at the Khar-Us, Khar, and Tsetsegt lakes to date. More surveys are needed to document its presence. Finally, we provide detailed distribution maps, photo illustrations, and taxonomic notes of four species.