Polygonum Amphibium Research Articles

Antioxidant activity of wild edible plants in the Black Sea Region of Turkey

The antioxidative activity of the 80% ethanol extract obtained from eleven commonly consumed wild edible plants was determined according to the phosphomolybdenum method, reducing power, metal chelating, superoxide anion and free radical scavenging activity and compared to standard compounds such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and trolox. Total phenolic compounds, flavonoids, and anthocyanins in the extracts were also measured. Trachystemon orientalis, Vaccinium mrytillus, Rumex acetosella Polygonum amphibium, Beta vulgaris, and Similax Excelsa had the highest antioxidant capacities. Overall results showed that these plants can serve as good sources of bioactive polyphenols in the human diet and can be regarded as good candidates for nutritional supplement formulations due to their high concentrations of total phenolic compounds, flavonoids and anthocyanins as well as their strong antioxidant activity.

A microcosm system to evaluate the toxicity of the triazine herbicide simazine on aquatic macrophytes

This study evaluates the effects of the triazine herbicide simazine in an outdoor pond microcosm test system that contained two submerged rooted species ( Myriophyllum spicatum and Elodea canadensis) and two emergent rooted species ( Persicaria amphibia and Glyceria maxima) over a period of 84 days. Simazine was applied to the microcosms at nominal concentrations of 0.05, 0.5 and 5 mg/L. General biological endpoints and physiological endpoints were used to evaluate herbicide toxicity on macrophytes and the algae developing naturally in the system. Concentration-related responses of macrophytes and algae were obtained for the endpoints selected, resulting in a no observed ecologically adverse effect concentration (NOEAEC) at simazine concentrations of 0.05 mg active ingredient/L after 84 days. E. canadensis was the most negatively affected species based on length increase, which was consistently a very sensitive parameter for all macrophytes. The experimental design presented might constitute a suitable alternative to conventional laboratory single-species testing.

High methane emissions from a littoral zone on the Qinghai-Tibetan Plateau

The littoral zones of lakes have been regarded as hotspots of methane (CH 4) fluxes through several studies. In the present study, we measured CH 4 fluxes in six kinds of littoral zones of Huahu Lake on the Qinghai-Tibetan Plateau in the peak growing season of 2006 and 2007. We found that CH 4 efflux (ranging from −0.1 to 90 mg CH 4 m −2 h −1) from the littoral zones of this lake was relatively high among those of boreal and temperate lakes. Our results also showed that emergent plant zones ( Hippuris vulgaris and Glyceria maxima stands) recorded the highest CH 4 flux rate. The CH 4 flux in the floating mat zone of Carex muliensis was significantly lower than those of the emergent plant zones. CH 4 fluxes in the floating-leaved zone of Polygonum amphibium and bare lakeshore showed no significant difference and ranked last but one, only higher than that of the littoral meadow ( Kobresia tibetica). Plant biomass and standing water depths were important factors to explain such spatial variations in CH 4 fluxes. No significant temporal variations in CH 4 fluxes were found due to the insignificant variations of physical factors in the peak growing season. These results may help in our understanding of the importance of the littoral zone of lakes, especially the emergent plant zone, as a hotspot of CH 4 emission.

Epiphytic meiofauna in stands of different submerged macrophytes

Epiphytic meiofauna in association with pure stands of four macrophytes (Nymphoides peltata, Ceratophyllum demersum, Polygonum amphibium and Carex spp.) were studied in the slow-flowing Conakut Channel, within the Kopacki rit floodplain, Croatia, during two vegetation seasons (2001 and 2002). The meiofauna densities for different macrophyte types showed a significant variation between N. peltata and C. demersum stands with a total of 15 meiofauna taxa on the macrophytes. Insect larvae, mostly Chironomidae, and Oligochaeta juveniles were the most abundant taxa recorded during the entire investigated period in all stands of macrophytes, except in P. amphibium.

Antimicrobial Activity of Some Water Plants from the Northeastern Anatolian Region of Turkey

The antimicrobial activity of methanol and acetone extracts of Butomus umbellatus, Polygonum amphibium, and two species of the genus Sparganium (S. erectum and S. emersum) against three Gram-positive, five Gram-negative bacteria and one fungus was assessed by the disk diffusion method. The microorganisms used were Staphylococcus aureus ATCC-29740, Escherichia coli ATCC-25922, Pseudomonas aeruginosa ATCC-15442, Salmonella typhi NCTC-9394, Klebsiella pneumoniae NCTC-5046, Proteus vulgaris ATCC-7829, Bacillus subtilis ATCC-6633, Corynebacterium diphteriae RSHM-633 and Candida albicans ATCC-10231. Methanol extracts of the plants did not exhibit any inhibitory activity against any of the microorganisms, while the acetone extracts of the all tested plants only showed significant activity against Bacillus subtilis, with inhibition zones and minimal inhibitory concentration values in the 7-16 mm and 0.49-12.50 mg/mL ranges, respectively.

Heavy metals in water, sediments and wetland plants in an aquatic ecosystem of tropical industrial region, India

Concentrations of heavy metals (Cu, Cr, Fe, Pb, Zn, Hg, Ni, and Cd) and macronutrients (Mn) were measured in industrial effluents, water, bottom sediments, and wetland plants from a reservoir, Govind Ballabh (G.B.) Pant Sagar, in Singrauli Industrial region, India. The discharge point of a thermal power plant, a coal mine, and chlor-alkali effluent into the G.B. Pant Sagar were selected as sampling sites with one reference site in order to compare the findings. The concentrations of heavy metals in filtered water, sieved sediment samples (0.4-63 microm), and wetland plants were determined with particle-induced X-ray emission. The collected plants were Aponogeton natans, L. Engl. & Krause, Cyperus rotundus, L., Hydrilla verticillata, (L.f.) Royle, Ipomoea aquatica, Forssk., Marsilea quadrifolia, L., Potamogeton pectinatus, L., Eichhornia crassipes, (Mart.) Solms Monogr., Lemna minor, L., Spirodela polyrhiza (L.) Schleid. Linnaea, Azolla pinnata, R.Br., Vallisneria spiralis, L., and Polygonum amphibium, L. In general, metal concentration showed a significant positive correlation between industrial effluent, lake water, and lake sediment (p < 0.01). Likewise, significant positive correlation was recorded with metals concentration in plants and lake ambient, which further indicated the potential of aforesaid set of wetland macrophytes for pollution monitoring.

Flavonoid glucuronides with anti‐leukaemic activity from Polygonum amphibium L.

The chemical and pharmaceutical studies carried out on species from Polygonum L. genus showed biological activity both of the extracts and the components isolated from them. These results were the impulse to examine Polygonum amphibium L. The aim of this study was the isolation of active components from methanol extract and the determination of their cytotoxic effect on human leukaemic cell lines. Three flavonoid components from butanol soluble fractions of methanol extract by CC and PC preparative chromatography were isolated. Their structures were established on the basis of 1H, 13C and correlation (DEPT, H-H, COSY, HMQC, HMBC) NMR, UV and FAB-MS spectroscopic techniques. The evaluation of the anti-leukaemic activities of 1 and 2 against Jurkat and HL60 cell lines was carried out in vitro using annexin V fluorescence assay. Two new flavonoid glucuronides, quercetin-3-O-beta-glucuronide (1) and quercetin-3-O-alpha-rhamnosyl-(1 --> 2)-beta-glucuronide (2), and kaempferol-3-O-alpha-rhamnosyl-(1 --> 2)-beta-glucuronide (3), were isolated from Polygonum amphibium L. It was demonstrated that the glucuronides of quercetin are able to induce apoptosis in the tested human leukaemic cells. These compounds penetrate through cytoplasm to the cellular nucleus of the cultured cells, and give intensive apoptotic responses in the stimulated leukaemic cells. The number of apoptotic cells increased with the concentration (1 nm to 10 microm) of 1 or 2 and periods of exposure (1-3 days). Compounds 1 and 2 may be considered good candidates for leukaemia chemotherapeutic agents.

Emergent and floating-leaved macrophytes as refuge for zooplankton in a eutrophic temperate lake without submerged vegetation

Several studies have shown that submerged macrophytes provide a refuge for zooplankton against fish predation, whereas the role of emergent and floating-leaved species, which are often dominant in eutrophic turbid lakes, is far less investigated. Zooplankton density in open water and amongst emergent and floating-leaved vegetation was monitored in a small, eutrophic lake (Frederiksborg Slotsso) in Denmark during July–October 2006. Emergent and floating-leaved macrophytes harboured significantly higher densities of pelagic as well as plant-associated zooplankton species, compared to the open water, even during periods where the predation pressure was presumably high (during the recruitment of 0+ fish fry). Zooplankton abundance in open water and among vegetation exhibited low values in July and peaked in August. Bosmina and Ceriodaphnia dominated the zooplankton community in the littoral vegetated areas (up to 4,400 ind l−1 among Phragmites australis and 11,000 ind l−1 between Polygonum amphibium stands), whereas the dominant species in the pelagic were Daphnia (up to 67 ind l−1) and Cyclops (41 ind l−1). The zooplankton density pattern observed was probably a consequence of concomitant modifications in the predation pressure, refuge availability and concentration of cyanobacteria in the lake. It is suggested that emergent and floating-leaved macrophytes may play an important role in enhancing water clarity due to increased grazing pressure by zooplankton migrating into the plant stands. As a consequence, especially in turbid lakes, the ecological role of these functional types of vegetation, and not merely that of submerged macrophyte species, should be taken into consideration.

FLOWER SPECIES USED IN AQUATIC LANDSCAPE DESIGN

The modern landscape designs are un-conceived without aquatic landscape design. The aquatic plants are essential for assuring a success ful and attractive landscape, conferring life and color even to the smallest landscape designs. The a ttractively part and mystery of water made landscape designs is not always due to the water mi rrors. It’s also due to aquatic species that reveal the beauty of the aquatic landscape design. We can compare this kind of aquatic specie like a „floating island of green”. Constantly the aquati c landscape design is related to the natural aspect of the water designs in the nature. This how we can find the most suitable plants for the aquatic landscape design. The aquatic landscape designs can be made by using some flower species that are adapted to this kind of environmental conditions. The plants c an be chosen not only by their ornamental value but for their need of water and environmental condi tions; witches are more important factors (the type of water landscape designs ‐ lakes, ponds, etc ). After plant habit and biological characteristics the aquatic plants are classified as: natant specie s, submerse species, plasters species, oxygen made species, water lily species. After their origin and placement area, the aquatic species can be classified as: species for humid and swamp areas, s pecies for areas with water depth between (1040 cm depth), water lily area for plant floating (d epth of 50 cm even more). For each place in the aquatic design there is neede d specie, each plant has its own space. In the water lily area ( Nymphaea sp.) can be planted Ranunculus aquatilis , Aponogeton distachyos , floating species ( Pistia stratioides , Eichhornia crassipes , Hydrocharis morsus-ranae , Stratioides aloides ) submerse species ( Myriophyllum spicatum , Ceratophyllum demersum �.a.), before their decorative effect this kind of plants improve the w ater content in oxygene reducing the development of alga in the water. In areas with small depth water it’s recommended species like: Sparganium erectum , Orontium aquaticum , Polygonum amphibium , Butomus umbelatus , Pontederia cordata . In the swamp area are recommended species like: Acorus calamus , Lythrum salicifolium , Iris pseudacorus , Darmera peltata , Lychnis floscuculi . In the humid area : Iris laevigata , Myosotis palustris , Lysichiton americanus , Primula pulverulenta . On the river borders: Carex elata , Polemonium coeruleum , Trollius europaeus , Tradescantia sp., Hosta sp. and ferns. Due to different types of aquatic landscape designs more and more public gardens are choosing this kind of landscapes.

Benthic macroinvertebrates associated with four species of macrophytes

AbstractBenthic macroinvertebrates associated with four species of macrophytes (Nymphoides peltata, Ceratophyllum demersum, Polygonum amphibium and Carex sp.) were investigated during two growing seasons (2001 and 2002) in the slow-flowing Čonakut Channel in the Kopački rit Nature Park in Croatia. A total of 31 macroinvertebrate taxa were found. C. demersum, a submerged plant with dissected leaves, supported the highest macroinvertebrate abundance, almost seven times more than N. peltata, a floating plant with undissected leaves, which harboured the lowest abundance during the research period. Chironomidae larvae (50–83%) and Oligochaeta (14–46%) were the most abundant groups recorded on all macrophyte species. Water-level fluctuation, because of its influence on the appearance and growth of aquatic vegetation, and the trophic state of water within the macrophyte stands seemed to be the main factors which affected the taxonomic composition and abundance of macroinvertebrates.

Heavy Metals in Aquatic Macrophytes from Two Small Rivers Polluted by Urban, Agricultural and Textile Industry Sewages SW Poland

This article presents the results from a study of the comparison of 2 lowland rivers: the Olobok and the Pilawa in southwest Poland polluted by urban, agricultural, and textile industry sewages. pH and concentrations of Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn, nitrate, nitrite, ammonia, phosphate, and sulfate were measured in water samples and concentrations of Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, N, Na, Ni, P, Pb, S, and Zn were measured in stream bottom sediments and in the aquatic macrophytes Elodea canadensis, Callitriche verna, Potamogeton crispus, Potamogeton natans, and Ceratophyllum demersum from the river Olobok and Elodea canadensis, Polygonum amphibium, Potamogeton crispus, and Veronica beccabunga from the river Pilawa. The matrix of concentrations of 16 elements in 27 plant samples of 7 species from 15 sampling sites of 2 rivers and concentrations of 15 elements and pH in water samples and 16 elements and pH in bottom sediment samples of these sites was submitted to numerical classification, which revealed that sampling sites from the rivers were differentiated by the value of factor 1 of principal component analysis (PCA), which was related to the pH of water, Ca, Cu, Mg, Mn, and Ni in water and Cd, Cr, Cu, Fe, K, Mg, Na, Ni, P, and S in bottom sediments. More polluted parts of both rivers were differentiated from less polluted parts by the value of factor 2 of PCA, which was related to Pb, Zn, and sulfates in water and Ca and Zn in bottom sediments. Macrophytes from the Olobok and Pilawa rivers were differentiated by the value of factor 1, which was related to Ca, Co, Cr, Cu, Fe, Mg, Ni, N, Na, Pb, and S. Groups of macrophytes of more and less polluted parts of both rivers differed by the value of factor 2, which was related to P, K, and Mn. Downstream of the sewage outputs in both rivers, a significantly increased level of pollution occurs with elements correlated with factor 1: Among others were Cu and Cr, typical for the textile industry along the river Pilawa, and among others were Mn and Ni, typical for the urban and agricultural activities in the river Olobok.

Evaluation of &lt;I&gt;Ostrinia nubilalis&lt;/I&gt; (Lepidoptera: Crambidae) Neonate Preferences for Corn and Weeds in Corn

Choice tests were conducted to determine feeding preferences of European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), neonates for 15 species of plants. Percentage of neonates accepting (found on) each leaf disc after 24 h was measured using choice tests. Initially, nine species of plants were evaluated. The following year, 10 plant species were evaluated during O. nubilalis first generation and 11 species during the second generation. Pennsylvania smartweed, Polygonum pennsylvanicum (L.), had the highest percentage of neonates accepting leaf discs in both years. Other plants with high acceptance rates included swamp smartweed, Polygonum amphibium L.; velvetleaf, Abutilon theophrasti Medicus; cocklebur, Xanthium strumarium L.; and yellow foxtail, Setaria glauca (L.). Corn, Zea mays L., consistently had low percentages of neonates accepting leaf discs along with common waterhemp, Amaranthus rudis Sauer. Implications these results may have on O. nubilalis host plant selection in central Iowa's corn dominated landscape are considered.

Aquatic macrophytes as a habitat for free-living nematodes

Abstract The composition, trophic structure and diversity of nematode assemblages associated with three aquatic macrophyte species (Polygonum amphibium, Carex sp., Ceratophyllum demersum) were surveyed. Sampled stands were present at the three sites of the north bank in the Čonakut Channel (Nature Park Kopački rit, Croatia). They were all submerged during the period of investigation, which included two vegetation seasons. Nematode abundances (expressed as a number of individuals per 100 g of macrophyte dry weight) differ between the two vegetation seasons and between the sites, but not between the macrophyte species. In total, 19 nematode species were recorded. Chromadorina viridis, C. bioculata, Brevitobrilus stefanskii, Eutobrilus notus, Prodorylaimus longicaudatus and Ethmolaimus sp. were associated with all macrophyte species. Genera Eutobrilus, Brevitobrilus and Chromadorina were present at the highest relative abundances. Species diversity (H and Simpson's D) and evenness (Pielou's J), calculated on the nematode species level, display little or no change in relation to different macrophyte species. Ceratophyllum demersum associated nematode fauna had distinct dominance of one species (Eutobrilus notus) and consequently lower evenness, which was not statistically significant. Chewers (CH) represented the dominant trophic group of total nematode abundance for all three macrophyte species followed by epistrate feeders (EF). Detritus feeders (DF) and suction feeders (SF) were represented by low relative abundances. This paper is a contribution to ecology of aquatic nematodes associated with macrophyte species in mesoeutrophic to eutrophic slow flowing channel.

Release of nitrogen and phosphorus from macrophyte stands of summer dried out sediments of a eutrophic reservoir

Spremberg Reservoir, Lusatia, Germany, is a linear reservoir which impounds the lowland River Spree to a length of 8km. Due to low summer runoff and continuous extraction from it for public water supply ca. 21 % of the total area (6.8 km 2 ) dried out from May/June to October/November in 2000. The seasonal P and N accumulation and release by the macrophytes growing on these areas were investigated. Two major groups of macrophyte stands, dominated either by water smartweed Polygonum amphibium L. (50-100 %) or by marsh cudweed Gnaphalium uliginosum L. (50-75 %), were distinguished. In September 2000, their above-ground biomass was harvested from from 15 representative 5 x 5 m plots. It varied between 34-420 g d.w. m -2 for P. amphibium and 76-120 g d.w. m -2 for G. uliginosum. Plant elemental composition, incubation of undisturbed sediment cores and litter bag exposure showed that the mean P accumulation rate of both stands (7.2 mg Pm -2 d -1 ) was less than the release rate (9.7 mg P m -2 d -1 ), whereas the N accumulation rate (57.4 mg N m -2 d -1 ) was higher than the release rate (43.4 mg N m -2 d -1 ). The temporary storage of 0.52 t P and 6.51 t N by the macrophyte stands was compensated by release rates orders of magnitude higher than the corresponding benthic release rates (0.03-0.06 mg Pm -2 d -1 , 1.03-2.08 mg N m -2 d -1 ) influencing the overall water quality of the reservoir periodically. Riparian zone fluxes apparently added little to the reservoir-wide internal loading since the high Fe supply guarantees an efficient P retention in the sediments.

Innovative uses of vegetated drainage ditches for reducing agricultural runoff

Vegetated agricultural ditches play an important role in mitigation of pesticides following irrigation and storm runoff events. In a simulated runoff event in the Mississippi (USA) Delta, the mitigation capacity of a drainage ditch using the pyrethroid esfenvalerate (Asana XL) was evaluated. The pesticide was amended to soil prior to the runoff event to simulate actual runoff, ensuring the presence of esfenvalerate in both water and suspended particulate phases. Water, sediment, and plant samples were collected temporally and spatially along the drainage ditch. Even with mixing of the pesticide with soil before application, approximately 99% of measured esfenvalerate was associated with ditch vegetation (Ludwigia peploides, Polygonum amphibium, and Leersia oryzoides) three hours following event initiation. This trend continued for the 112 d study duration. Simple modeling results also suggest that aqueous concentrations of esfenvalerate could be mitigated to 0.1% of the initial exposure concentration within 510 m of a vegetated ditch. Observed field half-lives in water, sediment, and plant were 0.12 d, 9 d, and 1.3 d, respectively. These results validate the role vegetation plays in the mitigation of pesticides, and that ditches are an indispensable component of the agricultural production landscape.

Influence of ethyl acetate extract and quercetin-3-methyl ether from Polygonum amphibium on activation lymphocytes from peripheral blood of healthy donor in vitro.

The influence of an ethyl acetate extract from Polygonum amphibium L. and quercetin-3-methyl ether isolated from them were examined on the human immune system. The investigations were made on peripheral blood mononuclear cells from healthy donors. The cells were stimulated by plant extract and quercetin-3-methyl ether in 24 h culture and analysed inflow cytometry. The following mice monoclonal antibody anti human activate markers were used: anti HLA-DR PE, anti CD25 FITC, anti CD69 FITC and anti CD71 FITC. The level of Interleukine-2 in blood serum and in culture supernatants was measured by ELISA method. Ethyl acetate extract from Polygonum amphibium caused the rise in the number of CD25 and HLA-DR positive lymphocytes and increased the expression of CD25 and CD71 antigens. The level of IL-2 was increasing for the duration of the culture, independently from the presence of stimulators. Besides quercetin-3-methyl ether, from herb of Polygonum amphibium L., trans-taxifolin, quercetin and kaempferol were isolated The structure of the isolated compounds was determined by spectroscopic (UV, (1)H NMR, (13)C NMR and CI-MS) methods.

Effects of aquatic macrophytes on water quality and phytoplankton communities in shallow lakes

We investigated aquatic macrophytes, water quality, and phytoplankton biomass and species composition in three shallow lakes with different levels of vegetation cover and nutrient concentration in Kushiro Moor, during August 2000. Trapa japonica can live in a wide range of nutrient levels. This species forms an environment with a steeper extinction of light, higher concentrations of dissolved organic carbon (DOC), lower concentrations of dissolved oxygen (DO) near the bottom, and lower concentrations of nitrate + nitrite and soluble reactive phosphorus (SRP) than other vegetation types. The pH was much higher in a Polygonum amphibium community, and the DO near the bottom did not decrease compared to a T. japonica community in the summer. The relationship between chlorophyll a and the limiting nutrient (total phosphorus (TP) when total nitrogen (TN) : TP is ≥10 and TN/10 when TN : TP is &lt;10) significantly differed between lakes with and without submerged vegetation. The chlorophyll a concentrations at a given nutrient level were significantly lower in water with submerged macrophytes than in water without them. Correspondence analysis showed that the difference in phytoplankton community structure across sites was largely due to the presence or absence of submerged macrophytes, and the ordination of phytoplankton species in the lakes with submerged macrophytes is best explained by environmental gradients of TN, chlorophyll, pH and SRP.

Genetically based polymorphisms in morphology and life history associated with putative host races of the water lily leaf beetle, Galerucella nymphaeae.

A host race is a population that is partially reproductively isolated from other conspecific populations as a direct consequence of adaptation to a specific host. The initial step in host race formation is the establishment of genetically based polymorphisms in, for example, morphology, preference, or performance. In this study we investigated whether polymorphisms observed in Galerucella nymphaeae have a genetic component. Galerucella nymphaeae, the water lily leaf beetle, is a herbivore which feeds and oviposits on the plant hosts Nuphar lutea and Nymphaea alba (both Nymphaeaceae) and Rumex hydrolapathum and Polygonum amphibium (both Polygonaceae). A full reciprocal crossing scheme (16 crosses, each replicated 10 times) and subsequent transplantation of 1,001 egg clutches revealed a genetic basis for differences in body length and mandibular width. The heritability value of these traits, based on midparent-offspring regression, ranged between 0.53 and 0.83 for the different diets. Offspring from Nymphaeaceae parents were on average 12% larger and had on average 18% larger mandibles than offspring from Polygonaceae parents. Furthermore, highly significant correlations were found between feeding preference of the offspring and the feeding preference of their parents. Finally, two fitness components were measured: development time and survival. Development time was influenced by diet, survival both by cross type and diet, the latter of which suggest adaptation of the beetles. This suggestion is strengthened by a highly significant cross x diet interaction effect for development time as well as for survival, which is generally believed to indicate local adaptation. Although no absolute genetic incompatibility among putative host races was observed, survival of the between-host family offspring, on each diet separately, was lower than the survival of the within-host family offspring on that particular host. Survival of offspring of two Nymphaeaceae parents was about two times higher on Nymphaeaceae than on Polygonaceae, whereas survival of offspring of two Polygonaceae parents was 11 times higher on Polygonaceae than on Nymphaeaceae (based on untransformed data). Based on these results, we conclude that genetically determined polymorphisms in morphology and feeding preference exist in G. nymphaeae, resulting in differential performance. Furthermore, in each diet separately, offspring of between-host family crosses were less fit than offspring of within-host family crosses. These results support the hypothesis that within this species two host races can be distinguished.

Phytoremediation of Polluted Waters Potentials and Prospects of Wetland Plants

To investigate the possible use of plants to remediate polluted waters, a pot experiment was carried out in the laboratory with five wetland plant species, i.e., sharp dock (Polygonum amphibium L.), duckweed (Lemna minor L.), water hyacinth (Eichhornia crassipes), water dropwort [Oenathe javanica (BL.) DC.] and calamus [Lepironia articulata (RETZ.) DOMIN]. Nitrogen (N), phosphorus (P) and three heavy metals, cadmium (Cd), mercury (Hg) and lead (Pb), were the objects of remediation. Sharp dock was found to be a good accumulator of N and P. Indeed, on a dry weight basis the shoots of sharp dock accumulated up to 6.4% of N and 1.1 % of P with BCF (bioconcentration factor) values of 2235 and 1568, respectively. Water hyacinth and duckweed strongly accumulated Cd with concentrations of 462 and 14200 mg/kg, respectively, and BCF values of 1225 and 2567, respectively. Water dropwort achieved the highest concentrations of Hg, i.e., 1.2 mg/kg with a BCF value of 807, whereas calamus achieved the highest concentrations of Pb, i.e., 512.4 mg/kg in its roots with a BCF value of 1217. Thus, it could be concluded that the above plant species are good candidates for phytoremediation of polluted waters, as follows: sharp dock through accumulation of N and P in its shoots, water hyacinth and duckweed as hyperaccumulators of Cd, water dropwort as an hyperaccumulator of Hg and calamus as an hyperaccumulator of Pb.

Transport and fate of atrazine and lambda-cyhalothrin in an agricultural drainage ditch in the Mississippi Delta, USA

Drainage ditches are integral components of agricultural production landscape, yet their contaminant mitigation capacity has been scarcely examined. If ditches are indeed capable of contaminant mitigation, then their use may serve as an alternative agricultural best management practice (BMP). A 50 m portion of an agricultural drainage ditch, located in the Mississippi Delta Management Systems Evaluation Area (MDMSEA), USA, was amended with a mixture of water, atrazine (2-chloro-4-ethylamino-6-isopropylamino- s-triazine) (herbicide) and lambda-cyhalothrin (λ-cyano-3-phenoxybenzyl-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethyl cyclopropanecarboxylate) (insecticide), simulating a storm runoff event. Pesticide amendment was achieved using a diffuser to disperse the mixture at an inflow point along the ditch (designated as “0 m”). Pesticide concentrations in water, sediment, and plants were monitored for 28 days. One hour following initiation of simulated runoff, mean percentages of atrazine concentrations measured in water and sediment were 37 and 2%, respectively, while mean percentages of lambda-cyhalothrin concentrations in water and sediment were 12 and 1%, respectively. Atrazine and lambda-cyhalothrin mean percentage concentrations in plants ( Polygonum (water smartweed), Leersia (cutgrass), and Sporobolus (smutgrass)) were 61 and 87%, respectively. Therefore, plants serve as an important site for pesticide sorption during runoff events. Aqueous concentrations of both pesticides decreased to levels which would not elicit non-target toxicological effects by the end of the 50 m portion of the drainage ditch. This research provides fundamental answers concerning the capability of vegetated agricultural drainage ditches to mitigate pesticide-associated storm water runoff.