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Like most aquatic plants, the pondweeds (Potamogetonaceae) are among the most phenotypically reduced and plastic of all angiosperms. As such, hypotheses of structural homology present difficulties for morphological phylogenetic reconstruction. We used non-coding nuclear and plastid DNA data to address Potamogetonaceae relationships and accompanying issues in character evolution and biogeography. Genera currently assigned to Potamogetonaceae, plus Zannichellia, formed a strongly supported monophyletic group. Potamogeton and Stuckenia (Potamogeton subg. Coleogeton) were both resolved as monophyletic. Within Potamogeton proper, two major clades followed the traditional split between broad- and narrow-leaved species, with the latter condition optimized as basal. Heterophylly (submerged plus floating leaves) has evolved several times, and the ancestral distribution for Potamogeton appears to be Northern Hemispheric. Our phylogenetic results have provided a useful genetic framework from which to interpret morphological, cytological and biogeographical evolution. ispartof: Cladistics vol:22 issue:6 pages:568-588 ispartof: location:United States status: published

Submerged macrophytes and their epiphytic biofilms are important media for metal transport/transformation in aquatic environment. However, the bacterial community structure and the contribution of the epiphytic biofilm to the heavy metal accumulation remain unclear. Therefore, in this study, water, sediment, submerged macrophyte (Potamogeton crispus L.) and its epiphytic biofilm samples in three sites of the moat in the industrial area of Hangzhou were collected for analyzing. The bacterial community structure was significantly impacted by the TN concentrations, and Genus Aeromonas (24.5-41.8%), Acinetobacter (16.2-29.8%) and Pseudomonas (12.6-23.6%) dominated in all epiphytic biofilm samples, which had the heavy metal pollutant resistibility. The contents of Cr in biofilms (7.4-8.3 mg/kg, DW) were significantly higher than those in leaves (1.0-2.4 mg/kg, DW), while the contents of Cu (11.0-13.9 mg/kg, DW) in leaves were significantly higher than those in biofilms (0.7-3.9 mg/kg, DW) in all the three sites. The BCF values of metals in the biofilm were followed the order of YF IC ETS. The results indicated that the epiphytic biofilm had positive effects on the metal bioaccumulation, and the metal accumulation ability increased with the hydrodynamic forces. Bioaccumulation by the epiphytic biofilm may be an effective way for metal (especially Cr) remediation.

In this study, four typical submerged macrophytes, namely

The current work investigated the potential of submerged macrophyte pondweed (Potamogeton malaianus) in treating cadmium, nickel, and lead-contaminated water through phytoremediation. The adsorption for the three metal ions occurred rapidly within 2 h and attained dynamic equilibrium in no more than 72 h. The removal efficiencies of Cd (II), Ni (II), and Pb (II) were high, passing 94% in both single- and multi-metal systems. The kinetic adsorption curves of Cd (II), Ni (II), and Pb (II) were fitted well by both pseudo-first-order and pseudo-second-order kinetics (R2 = 0.9875-0.9995). The equilibrium adsorption capacities of Cd (II), Ni (II), and Pb (II) for P. malaianus were 6.29-6.97 mg kg-1 . In plants, the higher concentration of each metal ions was accumulated in leaves (12.44-38.15 mg kg-1 ) than in roots (10.32-26.10 mg kg-1 ). The chlorophyll contents increased from 0.69 to 0.89-1.00 mg g-1 under the treatment of Cd (II), Ni (II), and Pb (II), whereas the chlorophyll a/b ratio was kept constant. There was no significant difference between single- and multi-metal systems. FT-IR spectra showed that COH and C═N might be involved in the adsorption of Cd (II), Ni (II), and Pb (II). This study demonstrated that P. malaianus could be a suitable submerged macrophyte for the simultaneous removal of Cd (II), Ni (II), and Pb (II) from water.

Natural antioxidants, especially those of plant origins, have shown a plethora of biological activities with substantial economic value, as they can be extracted from agro-wastes and/or under exploited plant species. The perennial hydrophyte, Potamogeton perfoliatus, has been used traditionally to treat several health disorders; however, little is known about its biological and its medicinal effects. Here, we used an integrated in vitro and in vivo framework to examine the potential effect of P. perfoliatus on oxidative stress, nociception, inflammatory models, and brewer’s yeast-induced pyrexia in mice. Our results suggested a consistent in vitro inhibition of three enzymes, namely 5-lipoxygenase, cyclooxygenases 1 and 2 (COX-1 and COX-2), as well as a potent antioxidant effect. These results were confirmed in vivo where the studied extract attenuated carrageenan-induced paw edema, carrageenan-induced leukocyte migration into the peritoneal cavity by 25, 44 and 64% at 200, 400 and 600 mg/kg, p.o., respectively. Moreover, the extract decreased acetic acid-induced vascular permeability by 45% at 600 mg/kg, p.o., and chemical hyperalgesia in mice by 86% by 400 mg/kg, p.o., in acetic acid-induced writhing assay. The extract (400 mg/kg) showed a longer response latency at the 3 h time point (2.5 fold of the control) similar to the nalbuphine, the standard opioid analgesic. Additionally, pronounced antipyretic effects were observed at 600 mg/kg, comparable to paracetamol. Using LC-MS/MS, we identified 15 secondary metabolites that most likely contributed to the obtained biological activities. Altogether, our findings indicate that P. perfoliatus has anti-inflammatory, antioxidant, analgesic and antipyretic effects, thus supporting its traditional use and promoting its valorization as a potential candidate in treating oxidative stress-associated diseases.

Reports on whether typical apertures occur in pollen of Althenia (Potamogetonaceae) are controversial. The question is of interest because relatively few submerged aquatic angiosperms possess local...

The interspecific hybrid Potamogeton ×salicifolius (= P. lucens × P. perfoliatus), so far known only from several countries of Europe and a few countries of Asia, was discovered in Western Australia. Morphology of the Australian specimens fits the variation range of the Eurasian specimens. DNA sequencing confirmed the morphological identification as a hybrid P. lucens × P. perfoliatus and identified the former species as the maternal one. This identity is surprising because none of the parental species are known to occur in Western Australia and P. lucens currently even does not occur in the continent. Three possible explanations for the occurrence of P. ×salicifolius in Western Australia are discussed: its relictual occurrence from the time when both the parental species occurred there, long-distance dispersal of a hybrid seed from Eurasia and the remnant of local cultivation or intentional planting.

Potamogetonaceae is one of the most diverse aquatic plant families in the world and in Turkey. No research has been done on environmental preferences of Potamogetonaceae species in Turkey. We aimed to understand the relationship between distribution of species and hydrochemistry using canonical correspondence analysis. Distribution and abundance patterns of species along an altitudinal gradient were also investigated. We collected 14 Potamogetonaceae species from 96 wetlands throughout Turkey and measured 10 water chemistry parameters. The most important environmental variables were electrical conductivity (EC), water temperature (Tw), dissolved oxygen (DO), and pH. These variables explained 5.9% of the total variance. Potamogeton coloratus had the lowest Tw and pH and the highest EC optima. Potamogeton gramineus preferred high Tw and pH and the lowest EC. Stuckenia amblyphylla had high DO and low Tw and EC preferences. Potamogeton natans sampled from highlands had the lowest DO optima. Stuckenia pectinata had the highest tolerance for EC and, along with P. crispus, the highest Tw tolerance. Remaining species are widespread with broad altitudinal distributions and average values of environmental parameters. The most vulnerable species are P. coloratus, S. amblyphylla and P. gramineus as they have special habitat preferences and narrow tolerances.

Groenlandia densa is globally a widely distributed species ; it has been recorded in the majority of the countries of the Western Balkans, however, the knowledge on its extant distribution in this particular area is limited and even controversial. In order to address this issue by tracking changes in species distribution over time and elucidating its current status in this area, we carried out a comprehensive survey of available literature sources and herbarium data, and performed field surveys. In Bosnia & Herzegovina, Montenegro and Croatia the species is most probably regionally extinct, while in Albania, Macedonia, Slovenia and Serbia G. densa occurs with only sparse records. Therefore, the most recent overview confirms this species as exceptionally rare in the Western Balkans. In Northern Europe the populations are declining due to various factors such as changes in climate and hydrology, prolonged periods of drought and irregular flooding, inappropriate water management, urbanisation, eutrophication, etc., and in the Western Balkans we have observed the same general trend. As a threatened species, G. densa urges for active conservation measures and thus our recommendation would be to re-assess this species on European level.

Aquatic macrophytes play a significant role in the nutrient cycle of freshwater ecosystems. However, nutrients from plant debris release into both sediments and overlying water if not timely harvested. To date, minimal information is available regarding nutrient release and its subsequent influences on bacterial communities with decaying debris. In this study, Potamogeton crispus was used as a model plant. Debris biomass levels of 0 g (control, J-CK), 10 g dry weight (DW) (100 g DW/m2, J-10 g), 40 g DW (400 g DW/m2, J-40 g) and 80 g DW (800 g DW/m2, J-80 g) were used to simulate the different biomass densities of P. crispus in field. The physicochemical parameters of overlying water and sediment samples were analysed. The community composition of anammox bacteria in the sediment was also analysed using 16S rRNA genes as markers. The results showed that dissolved oxygen and pH dramatically decreased, whereas total nitrogen (TN) and NH4+-N concentrations increased in the overlying water in the initial stage of P. crispus decomposition. However, NO3−-N concentration changes in the overlying water were more complicated. The concentrations of organic matter, TN and NH4+-N in the sediment all increased, but the rate of increase varied among the groups with different initial biomass levels, indicating that these physicochemical properties in sediment are significantly affected by debris biomass level and decay time. In addition, the order of anammox bacteria abundance was J-40 g > J-CK > J-80 g > J-10 g. Moreover, the community structure of anammox bacteria were simpler compared to that of J-CK as debris biomass level increased. The results demonstrate that P. crispus debris decomposition could affect the ecological distribution of anammox bacteria. Such influence clearly varies with varying amounts of P. crispus biomass debris. This information could be useful for the management of aquatic macrophytes in freshwater ecosystems.

Kottaimuthu, Ramalingam, Kumar, John Kennedy John Praveen, Dineshkumar, Panjavarnam, Logeshwari, Maruthan (2021): A new name for extant Potamogeton × mirabilis (Potamogetonaceae). Phytotaxa 498 (1): 69-70, DOI: 10.11646/phytotaxa.498.1.9, URL: http://dx.doi.org/10.11646/phytotaxa.498.1.9

A sediment-water mesocosm experiment was set up to identify the effects of different debris biomass P. crispus decomposition on water body physicochemical properties and greenhouse gas emissions in Dongping Lake, a typical shallow macrophytic lake in the north of China. The results indicated that the decomposition of high biomass (BL-2) of P. crispus could significantly affect the physicochemical properties of water bodies, especially within the first 47 days. During the experiment, DO and water pH in BL-2 were significantly lower, while NH3-N, NO2--N, DOC, and DRP in surface water and OM in sediment were significantly higher than those in the low biomass treatment (BL-1) and zero control (CK). Moreover, the DOC in BL-1 were significantly higher than CK. The decomposition of P. crispus significantly affected the emission fluxes of CH4 and CO2, but had no significant impact on N2O emission. CH4 and CO2 fluxes were generally more significantly correlated with the properties of surface water in BL-2 than in BL-1. High debris biomass decomposition significantly promoted the emission of CH4 enhancing the source effect of water body, while the decomposition of both low and high biomass notably promoted the emission of CO2 converting the water bodies from sink to source of CO2. There were significant differences in global warming potential among the three groups in which CH4 contributed most. Considering the negative impact on water environment and elevated carbon emission during the decomposition of P. crispus, it was suggested to strengthen the management of P. crispus in Dongping Lake.

summary The paper describes monthly biomass, seasonal and annual net primary productivity and monthly and seasonal nutrient content of four submerged macrophytes in a lentic wetland situated in the campus of Banaras Hindu University. The seasonal variation of six nutrients (NO3 -N, PO4-P, K, Ca, Mg, Na) in water is described and their mean concentrations used in multiple regression equations to examine the relationship between nutrients in water, plant biomass and nutrient accumulation in plant body. Hydrilla verticillata (L.f.) Royle, Potamogeton crispus L., P. pectinatus L. and Aponogeton natans (L.) Engle and Krause are the constituent species. Plants show rapid growth in post-monsoon and pre-winter months. All the four species showed biomass accumulation in the rainy season. The highest rate of production in the submerged zone was 0.73 g m−2 d−1 and the minimum was 0.29 g m−2 d−1. Maximum annual production of any species was 69 g m−2 in P. pectinatus. In all the four species the nutrient concentration decreased in the following order: calcium > nitrogen > potassium > magnesium > sodium > phosphorus. Seasonal variation of nutrient content was dependent on the period of germination, growth and development of the species. Nitrogen, phosphorus and potassium were higher in the season of growth of particular species and calcium was higher when plants matured. There was no definite trend for sodium, though magnesium varied with species. Uptake and accumulation of nutrients in submerged plants largely depend upon nutrient concentration of water, except nitrogen which was also dependent on biomas change. Sources of nutrient for plants are both sediment and water. Translocation of potassium from the overlying water to the mud by Hydrilla plants is possible as there is reduction in potassium concentration of water around Hydrilla.

Macrophytes are usually chosen for phytoremediation tools to remove P in eutrophic aquatic ecosystems, but the lack of test methods hinders the understanding of removal mechanism and application. In this study, we used the novel technologies combined of Diffusive gradients in thin films (DGT), Planar optode (PO), and Non-invasive micro-test technology (NMT) to explore P dynamics in water-sediment continuum and rhizosphere of Potamogeton crispus over time. Results of the high-resolution in situ measurement showed that labile P(LPDGT) fluxes at the surficial sediment significantly decreased from approximate 120, 140, and 200 pg/ (cm2•sec) via 30 days incubation period to 17, 40, and 56 pg/(cm2•sec) via that of 15 days. Obvious synchronous increase of LPDGT was not detected in overlying water, suggesting the intense assimilation of dissolve reactive P via root over time. PO measurement indicated that O2 concentration around the rhizosphere remarkably increased and radially diffused into deeper sediment until 100% saturation along with the root stretch downwards. NMT detection of roots showed the obvious O2 inflow into root tissue with the uppermost flux of 30 pmol/(cm2•sec) from surroundings via aerenchyma on different treatment conditions. Different from previous reports, gradually saturating O2 concentrations around the rhizosphere was principally driven by O2 penetration through interspace attributing to root stretch downward rather than root O2 leakage. Increased O2 concentrations in deep sediment over time finally induced the oxidization of labile Fe(II) into Fe(III) bound P and local P immobilization.

A climatic heterogeneity and geomorphologic complexities that have been shaped during a sophisticated paleo-biogeographical history has led Iran to become a prominent zone of endemism, an endemic center of the Irano-Turanian region, and a global center of diversity for vascular plant taxa in the world. According to the present study, Iranian macrophyte flora includes 68 species of 35 genera of vascular plants belonging to 22 plant families. The Potamogetonaceae family, with 16 species, is the largest family of true aquatic plants in the country. The aquatic plants were distributed between −29 m (Wolffia arrhiza (L.) Horkel.) and 3200 m (Triglochin palustris L.). The greatest number of species (48 species) occurs at an altitude of 0–500 m. Hydrocharitaceae and Potamogetonaceae comprise the largest number of endangered and critically endangered species of Iranian aquatic plants. The main hotspot of species richness of true aquatic plants occurred in the Hyrcanian phytogeographical region, followed by an area in the Atropatanean region. The highest value of AZEs exists in Gilan Province. Despite the high importance of these habitats from a conservation perspective, numerous direct and indirect man-made threats such as pollution, invasive plants, and climate change have exposed these habitats.

Toxicity in aquatic plants, caused by excess ammonium in the environment, is an important ecological problem and active research topic. Recent studies showed the importance of the enzyme Glutamate Dehydrogenase (GDH) in detoxifying ammonium. However, these results mainly derived from species comparisons, hence some mechanisms may have been obscured due to species differences. Our recent finding that young leaves of Potamogeton lucens were less sensitive to ammonium enrichment, than mature leaves allowed us to study ammonium detoxification within a species. We found that, unlike mature leaves, ammonium-tolerant young leaves of P. lucens could assimilate ammonium mainly through GDH. There was a 38% increase of NADH-dependent GDH in 50 mg/L ammonium concentration compared with 0.1 mg/L. Therefore, this study confirms the hypothesis that the GDH pathway plays a major role in the detoxification of ammonium in freshwater macrophytes.

The accumulation of atrazine in sediments raises wide concern due to its potential negative effects on aquatic environments. Here we collected sediments and different submerged macrophytes to simulate natural shallow lakes and to measure atrazine levels and submerged macrophyte biomass. We determined gene expressions in submerged macrophytes treated with or without atrazine. We also examined atrazine concentrations and its metabolite structures in submerged macrophytes. When the initial concentration of atrazine in sediments ranged from 0.1 to 2.0 mg kg−1 dry weight (DW), atrazine levels in the pore water of the sediments ranged from 0.003 to 0.05 mg L−1 in 90 days. Atrazine did not show obvious long-term effects on the biomass of Potamogeton crispus and Myriophyllum spicatum (P > 0.05). On day 90, gene expressions related to cell wall in P. crispus were changed by atrazine phytotoxicity. Moreover, the decrease in the number genes controlling light-harvesting chlorophyll a/b-binding proteins verified the toxic effects of atrazine on the photosynthesis of M. spicatum. Compared with unexposed plants on day 90, ribosome pathway was significantly enriched with differentially expressed genes after submerged macrophytes were exposed to 2.0 mg kg−1 DW atrazine (P 0.05). Once absorbed by submerged macrophytes, atrazine was degraded into 1-hydroxyisopropylatrazine, hydroxyatrazine, deethylatrazine, didealkylatrazine, cyanuric acid, and biuret, and some of its metabolites could conjugate with organic acids, cysteinyl β-alanine, and glucose. This study establishes a foundation for aquatic ecological risk assessments and the phytoremediation of atrazine in sediments.

The micro-environment formed by the photosynthesis of submerged plants is conducive to the formation of CaCO

Clasping-leaved Potamogeton L. species growing in Turkey are P. praelongus Wulfen and P. perfoliatus L. There exists no detailed study about distribution, habitat requirements, and anatomical properties of the Turkish populations of the two species. Potamogeton perfoliatus is widespread throughout the country but P. praelongus was recorded only from a single locality. Therefore, P. praelongus is rare and endangered in Turkey. In this study, we recorded presence of P. perfoliatus in 54 wetlands based on examination of 86 herbarium specimens. Physical and chemical parameters of the water bodies where the two species occur were measured from 24 sites for P. perfoliatus and from one site for P. praelongus. According to our findings, P. praelongus grows in an alpine lake with oligotrophic, calcareous and alkaline water. Potamogeton perfoliatus occupies diverse habitats but prefers deep lentic water bodies with high pH and low salinity levels. Stem anatomy of the species were studied based on three individuals for P. praelongus and 35 individuals for P. perfoliatus. Morphological features of the species were also investigated and descriptions based on Turkish material were prepared. We provided the distinguishing anatomical and morphological characters between the species. Our anatomical findings showed that P. praelongus specimens have eight vascular bundles in contrast to previous reports on the species. Our results can be used for future monitoring of the two submerged Potamogeton species as we provide detailed information about their current distribution pattern and habitat features., Türkiye’de yetişen gövdeyi saran yapraklı Potamogeton L. türleri P. praelongus Wulfen ve P. perfoliatus L.’tur. Bugüne kadar bu türlerin dağılımı, habitat tercihleri ve anatomik özellikleriyle ilgili detaylı çalışmalar yoktur. Potamogeton perfoliatus ülke çapında yaygın bir türdür ancak P. praelongus sadece bir lokaliteden kaydedilmiştir. Bu nedenle P. praelongus Türkiye’de nadir ve tehdit altındadır. Bu çalışmada 86 herbaryum örneğine dayanarak P. perfoliatus’u 54 sulak alandan kaydettik. Türlerin yetiştiği suların fiziksel ve kimyasal parametreleri P. perfoliatus için 24 noktadan, P. praelongus için bir noktadan ölçülmüştür. Bulgularımıza göre, P. praelongus oligotrofik, kalkerli ve alkali alpin bir gölde yetişmektedir. Potamogeton perfoliatus çok farklı habitatlarda bulunmakla birlikte, yüksek pH, düşük tuzluluk değerlerine sahip, derin ve durgun suları tercih etmektedir. Türlerin gövde anatomileri P. praelongus için 3 birey, P. perfoliatus için ise 35 bireyden örnek alınarak incelenmiştir. Türlerin morfolojik özellikleri de araştırılmış ve Türkiye’den toplanan materyallere dayalı olarak betimler hazırlanmıştır. Türler arasındaki ayırt edici anatomik ve morfolojik karakterler verilmiştir. Anatomi bulgularımız P. praelongus’un önceki bazı çalışmalara aykırı olarak sekiz iletim demetine sahip olduğunu göstermektedir. Bu çalışmada türlerin güncel dağılım ve habitat tercihleriyle ilgili sunduğumuz kapsamlı bulgular iki batık Potamogeton türünün gelecekte izlenmesinde faydalı olacaktır.

Long-term trends of artificial radionuclides, from 2003 to 2018, in two abundant species of macrophytes, shining pondweed, Potamogeton lucens, and water moss, Fontinalis antipyretica, have been analyzed to estimate the indicative reliability of these two species as biomonitors of radioactive contamination in a river system and to quantify the decrease in the content of artificial radionuclides in the Yenisei River. Time-dependent trends of artificial radionuclides in the biomass of these species were similar, resulting in estimates of effective half-lives for 54Mn, 58Co, 60Co, 65Zn, 137Cs, and 152Eu similar for both species. Concentrations of artificial radionuclides in biomass of shining pondweed and water moss correlated with annual discharges of the radionuclides to the Yenisei at different levels of significance, and the strongest (R2 > 0.7) positive correlation (p

Content of some heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) and macroelements (Ca, Mg, Na, and K) were determined in samples of water, sediment, macrophytes (Potamogeton crispus, Potamogeton perfoliatus, Myriophyllum spicatum, and Chara vulgaris), and leech (Hirudo sulukii n. sp.) collected from Kara Lake Adiyaman, Turkey at four distinct seasons using inductively coupled plasma optical emission spectrometer (ICP-OES). It was found that the studied heavy metals were completely below the detection limit of ICP-OES for water samples. The results showed that most heavy metals (Ni, Cr, Zn, Fe, and Pb) and macroelements (Mg and Na) had their highest values in sediment samples in August. Increases of heavy metals and macroelements may be due to evaporation because of summer stagnation at this period. The average content of studied elements was in the order of Mn>Ni>Cr>Zn>Fe>Pb>Cu in sediment samples. As a non-essential heavy metal, Cr was the most accumulated in all the macrophytes studied. The average Cr concentration was in the order of P. crispus > P. perfoliatus > M. spicatum > C. vulgaris. In C. vulgaris, the accumulation of Ca was the highest compared with other macrophytes. The accumulation of heavy metal was in the order of Fe>Zn>Cu>Pb>Mn>Cr>Ni>Cd in H. sulukii n. sp. The obtained results showed that the heavy metal and macroelement (Na, Ca, Mg, and K) concentrations in water, sediment, macrophytes, and leech are below the risk values according to the aquatic life pollutant data provided by the U.S. Environmental Protection Agency. Overall, the element contents can be attributable to the geological sources because of the general absence of serious pollution in Kara Lake, Adiyaman, Turkey.

Montezuma Well is a geothermal limnocrene spring within Montezuma Castle National Monument, Yavapai County, Arizona, U.S.A. The Well’s unusual geological qualities, water chemistry, and a history of aquatic plant collecting are discussed. Evidence to support the fact that a unique species of Potamogeton has likely grown in this location for thousands of years and is now recognized as the seventh apparent autochthonous endemic species from this small area is presented. Although this new species shares a few superficial characters with P. illinoensis Morong, it is easily distinguished by its massive height (7–8 m tall), lack of floating leaves, long acuminate leaf apices of its submerged leaves, and bright translucent green leaf color. A complete description with drawing and photographs is provided.

Fulvic acid (FA) plays a key role in governing the environmental geochemistry behavior of heavy metals. In this work, the roles of major functional groups were investigated based on binding experiments of heavy metals on natural FA extracted from lake sediments. The results showed that the adsorption capacities were ranked as Cu2+ > Pb2+ >Cd2+. The differences of peak area at 3412, 1713, 617and 2430 cm−1 pre- and post-binding reactions in FTIR spectra suggested that phenolic, carboxyl and nitrogen-containing groups were the major functional groups providing sites binding heavy metals. Moreover, the results of bi-Langmuir model and the ionic strength effects jointly indicated that electrostatic attraction was the key mechanism during the adsorption process. The fitted results of Ligand-binding model suggested that the major functional groups in FA were classified into two types binding sites: weak (i.e. phenolic and carboxyl groups) and strong binding sites (i.e. nitrogen-containing groups). Additionally, there might be p-benzoquinone-like formed in FA which were then reduced to hydroquinone during the adsorption process, corresponding to the changing of peak area at 1614 and 830 cm−1 in FTIR spectra, the occurrence of Peak C in Fluorescence excitation-emission matrix (EEM) spectra and the ratios of H/C (

This study investigated the ability of Potamogeton pectinatus L. to accumulate copper and its effects on plants. In accumulation tests, macrophytes were exposed (96 h) to different copper concentrations (0–1000 µM) and the metal was measured in media and plant tissues (roots, stems and leaves) to determine the bioconcentration factor (BCF). Plants accumulated high concentrations of copper in a dose-dependent manner and roots was the main organ for copper accumulation. However, the more copper increased in water, the more BCF values decreased. It may be due to either saturation of copper uptake or down-regulation of metal uptake by plants. In the physiological and morphological analyses, plants were kept (96 h) in Hoagland nutrient solution without copper, in full Hoagland solution (0.5 µM Cu) and in Hoagland medium with copper from 1 to 100 µM. The absence and the presence of copper above to 1 µM inhibited photosynthesis. Chlorophylls and carotenoid levels also decreased with the excess of copper, a fact that may have affected the photosystem II-dependent of chlorophyll and caused photosynthesis suppression. Only macrophytes at 10 µM Cu showed decrease in length and number of leaves on the 10th day of the test, when they died. Chlorosis and necrosis were observed in control groups and groups with extra copper, but not in Hoalgand group. Overall, the macrophyte P. pectinatus can be considered a suitable plant for monitoring environments contaminated by copper, based on results of copper accumulation in the plant, decrease in pigment concentration and presence of chlorosis and necrosis. However, values of BCF based on fresh water tissues was not proper to indicate the use of P. pectinatus for cleaning environments contaminated by copper.

The new species Groenlandia pescheri D. Uhl & Poschmann sp. nov., belonging to the family Potamogetonaceae, is described from the Late Oligocene Fossil-Lagerstätte Enspel (Westerwald, Germany). The species is characterized by sub-oppositely arranged leaves without observable stipule-like appendages at the leaf bases and a very thin exocarp (both characteristics of the aquatic genus Groenlandia J. Gay) with a spiked crest (which differs from the only other species included in this genus, the modern Groenlandia densa (L.) Four.). The taxon represents the first pre-Quaternary record of the genus Groenlandia, which is usually regarded as a basal sister group of all other Potamogetonaceae.

Submerged macrophytes and biofilms are important components of wetlands. However, little is known about the changes of microbes in biofilms attached to submerged macrophytes upon nitrogen loading. This study investigated the changes of microbes, algae, nitrifiers and denitrifiers in biofilms attached to the leaves of artificial plants (AP), Potamogeton malaianus (PM), Vallisneria natans (VN) and Hydrilla verticillata (HV) under varied initial concentrations of total nitrogen (TN). Nitrogen addition increased biofilm biomass and changed dissolved oxygen concentrations and pH values in overlaying water. Epiphytic algal densities showed the same trend at the same N level:AP > PM > VN > HV. As revealed by cluster analysis at phylum level, algae compositions in biofilm from four plants showed some host-specific at 2 and 12 mg L − 1 TN, but was clustered in the same group at 22 mg L − 1 TN regardless of plant species. Submerged macrophytes had better performance in total N removal than AP. In general, N application significantly increased the abundance of amo A, nir K, nir S, nap A and cnor B in biofilm. The abundance of the denitrification genes ( nir K, nir S, nap A, narG and cnor B) was positively correlated with nitrogen application, while amo A was correlated with concentration of dissolved oxygen. These results indicate that N loadings stimulated the growth of biofilms attached to submerged macrophyte and the removal of total N can be partially ascribed to the synergistic interactions of submerged macrophyte and biofilms in wetlands. These results highlight the ecological role of submerged macrophyte-biofilm system in nitrogen removal in wetlands.

A presente lista de Alismatales engloba quatro familias: Alismataceae, Araceae (Lemnoideae), Hydrocharitaceae e Potamogetonaceae . O estudo considerou coletas nos Herbarios do Mato Grosso do Sul (CGMS, CPAP), alem do R para Alismataceae . O numero total de especies mencionadas para o estado e de 41, sendo duas introduzidas ( Egeria densa Planch. e Vallisneria spiralis L.), ja citadas e coletadas no Mato Grosso do Sul. A familia mais rica e Alismataceae , e o genero mais numeroso Echinodorus Rich. ex Engelm. (12 especies), ca. 24% do total. Echinodorus cordifolius (L.) Griseb. no Pantanal e uma ocorrencia disjunta. Sagittaria planitiana G. Agostini e a primeira citacao para o estado.

The Sarno River is considered the most polluted river in Europe and one of the ten most polluted rivers in the world. So far, its quality has been usually evaluated by water and sediment analyses of either inorganic or organic pollutants. However, a biomonitoring approach would be of paramount importance in the evaluation of river quality, since it integrates pollutant temporal fluctuations, as in the case of discontinuous inputs from urban, industrial and agricultural activities. To this end, a passive biomonitoring study of the Sarno River was carried out, using two native aquatic plants accumulators of inorganic pollutants. The spring area was monitored analysing the roots of the semi-submerged Apium nodiflorum, whereas the whole river course was monitored analysing the shoots of the submerged Potamogeton pectinatus. The information on the four macronutrient (Ca, K, Mg, P), the six micronutrient (Cu, Fe, Mn, Na, Ni, Zn) and the four toxic element (Cd, Cr, Pb, V) concentrations were separately combined in the Nemerow Pollution Index. Results evidenced a severe pollution degree of the Sarno River, attributable to toxic elements > micronutrients > macronutrients. In particular, the spring area showed high K concentrations, as well as high concentrations of several micronutrients and toxic elements. A generalized Zn contamination and a progressive macronutrient (above all Ca and P), micronutrient (above all Ni, Cu and Fe) and toxic element (above all Cr and Pb) accumulation toward the mouth was related to pollution from agricultural and urban activities. Industrial sources, especially tanneries along the Solofrana tributary, accounted for high Mn concentrations, whereas the volcanic origin of the substrate accounted for a generalized V contamination.