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This study aimed at investigating the impacts of aquatic extracts of two macrophytes Typha domingensis (Pers) and Lemna minor(Lamarc) on the Ecophysiology of the common carp Cyprinus carpio (Linnaeus) reared in waste water. A total of eighty fish were divided into four groups, each group consists of ten fish. Four treatment were used with two replicates of they were made as follow; waste water, clean water (control), waste water- extract of T. domingensis and waste water- extract of L. minor. Healthy freshwater common carp weighing about 35.75 ± 0.60g were obtained from the aquaculture station of Marine Science Centre /University of Basrah. Physicochemical properties of waters used were recorded and controlled. The diet given to waste water–aquatic plant extract groups was mixed for one night. Blood smears were taken. White blood cells/1 mm3 were counted by using Neubaur Improved Haemocytometer and light compound microscope. The results indicated that the number of white blood cells of common carp for the control sample was more than that of waste water. While the numbers of white blood cells of the fish in separately treated waste water with T. domingensis and L. minor extracts were close to the number of the control sample. Blood smears of fish reared in clean water (control sample), waste water- T. domingensis extract and waste water- L. inor extract seemed quite normal, where as the smear of the blood of fish reared in waste water showed abnormalities in the blood such as disruption of cell walls and deformation of the shape of red blood cell.

Humans have domesticated diverse species from across the plant kingdom, however our current understanding of plant domestication is largely founded on major cereal crops. Here, we examine the evolutionary processes and genetic basis underlying the domestication of water caltrop (Trapa spp., Lythraceae), a traditional, yet presently-underutilized non-cereal crop that sustained early Chinese agriculturalists. We generated a chromosome-level genome assembly of tetraploid T. natans, and then divided the allotetraploid genome into two subgenomes. Based on resequencing data from 57 accessions, representing cultivated diploid T. natans, wild T. natans (2x and 4x) and diploid T. incisa, we showed that water caltrop was likely first domesticated in the Yangtze River Valley as early as 6,300 yr BP, and experienced a second improvement c. 800 years ago. We also provided strong support for an allotetraploid origin of T. natans within the past 230,000-310,000 years. By integrating selective sweep and transcriptome profiling analyses, we identified a number of genes potentially selected and/or differentially expressed during domestication, some of which likely contributed not only to larger fruit sizes but also to a more vigorous root system, facilitating nutrient uptake, environmental stress response, and underwater photosynthesis. Our results shed light on the evolutionary and domestication history of water caltrop, one of the earliest domesticated crops in China. This study has implications for genomic-assisted breeding of this presently underutilized aquatic plant, and improves our general understanding of plant domestication.

Investigations of the susceptibility of aquatic plants to species of Phytophthora are limited. Therefore, the objective of this study was to assess the potential susceptibility of six aquatic plant species, frequently used in constructed wetlands or vegetated channels, to infection by five species of Phytophthora commonly found at nurseries in the southeastern United States. In a greenhouse experiment, roots of each plant species (Agrostis alba, Carex stricta, Iris ensata ‘Rising Sun’, Panicum virgatum, Pontederia cordata, and Typha latifolia) growing in aqueous solutions were exposed to zoospores of each of the species of Phytophthora (Phytophthora cinnamomi, Phytophthora citrophthora, Phytophthora cryptogea, Phytophthora nicotianae, and Phytophthora palmivora). Zoospore presence and activity in solution were monitored with a standard baiting bioassay with rhododendron leaf discs as baits. Experiments were initiated in 2016 and repeated in 2017 and 2018. During the 2016 trials, Phytophthora spp. were not isolated from the roots of any of the plants, but some roots of C. stricta, P. virgatum, and T. latifolia were infected with multiple species of Phytophthora during trials in 2017 and 2018. Presence of plant roots reduced the percentage of rhododendron leaf discs infected by zoospores of four of the species of Phytophthora but not those infected by P. cinnamomi, which suggested that roots of these plants negatively affected the presence or activity of zoospores of these four species of Phytophthora in the aqueous growing solution. Results from this study demonstrated that certain aquatic plant species may be sources of inoculum at ornamental plant nurseries if these plants are present naturally in waterways or used in constructed wetlands treating water flowing off production areas, which could be of concern to plant producers who recycle irrigation water.

Typha orientalis is an important aquatic plant and is sensitive to the water level. Here, the ecological amplitude of T. orientalis under different water levels was determined by measuring its growth and physiological indices. Results showed that: (1) The growth characteristics of T. orientalis showed quadratic relationships with water level, plant height, withered leaf rate, base diameter, leaf length, leaf width, leaf area, and biomass. Each of these growth characteristics showed an increasing then decreasing trend as water level was increased. (2) Most physiological characteristics of T. orientalis (Chla, Chlb, Car, SOD activity, CAT activity, soluble protein content, and root activity) also showed quadratic relationships (increasing then decreasing) with an increase in water level. Conversely, POD activity and MDA content showed an inverted quadratic relationship, as they decreased then increased as water level increased. (3) We determined an optimum water level for T. orientalis growth of 14.43 cm, a range of limiting water levels for T. orientalis growth of −52 cm to 74.93 cm, with the range of −19.75 to 42.55 cm being the most suitable for growth. Water levels in excess of 74.93 cm and below −52 cm cannot facilitate the normal growth and development of T. orientalis.

Aponogeton lakhonensis A. Camus is rediscovered after a gap of 123 years from India. The detailed morphology of the plant along with a comparative analysis with Aponogeton natans (L.) Engler & Krause has been provided in this study supported by photographic illustrations.

The Bunder Reservoir Ecosystem is composed of various components, both biotic and abiotic. One of the components contained in the reservoir is aquatic plants as phytoremediator for wastewater. The aquatic plant inventory in the Bunder Reservoir aims to determine the diversity of aquatic plant species that have the potential to phytoremediate industrial waste. The research design was descriptive qualitative exploratory. Aquatic plant species were collected using a subjective estimates method with visual techniques. In the waters of the Bunder Reservoir, 17 species of aquatic plants from 13 families were found, including 11 emergent types, 1 free floating, 4 rooted floating, and 1 submersed. Types that have the potential to act as phytoremediators for inorganic waste in the metal categories are A. philoxeroides, A. sessilis, Cyperus sp. Hygrophila sp., I. carnea, I. aquatic, L. perpusilla, N. nucifera, Nymphaea sp., N. indica, P. barbata, and T. latifolia. The aquatic plant that has the potential for phytoremediator of pesticide waste is L. adscenden. While S. sesban tends to remove oil pollutants. Organic waste degrading species consist of T. latifolia, L. perpusilla, I.aquatica, Cyperus sp., And Brachiaria sp

We investigated the relative sensitivity of duckweed Lemna minor and six species of algae to seven herbicides, using an efficient high-throughput microplate-based toxicity assay. First, we assessed the sensitivity of L. minor to the seven herbicides, and then we compared its sensitivity to that of previously published data for six algal species based on EC50 values. For five herbicides, the most sensitive species differed: L. minor was most sensitive to cyclosulfamuron: Raphidocelis subcapitata was most sensitive to pretilachlor and esprocarb: Desmodesmus subspicatus was most sensitive to pyraclonil; and Navicula pelliculosa was most sensitive to pyrazoxyfen. Simetryn was evenly toxic to all species, whereas 2,4-D was evenly less toxic, with only small differences in species sensitivity. These results suggested that a single algal species cannot represent the sensitivity of the primary producer assemblage to a given herbicide. Therefore, to assess the ecological effects of herbicides, aquatic plant and multispecies algal toxicity data sets are essential.

Aquatic macrophytes are a key group in flooded areas due to their high primary productivity, and several species present in the Amazonian floodplains have potential for human food use. This study evaluated biomass production and nutrient levels in fronds of Ceratopteris pteridoides (Pteridaceae), under the following nutritional treatments: (T1) artesian well water, (T2) natural lake water, and (T3) artesian well water with a nutritive solution. Each replicate had 25 plants of 25 g total fresh biomass each. The experiment lasted for 35 days and total fresh biomass weight, root system length, leaf dry biomass weight, root dry biomass weight and sprout number were assessed. The plants from T3 had the greatest increase in total fresh biomass with an average of 430.02 g, showing that the nutritive solution used in the experiment provided the best conditions for plant growth. The daily ingestion of C. pteridoides could contribute to mineral supplementation, in addition to diversifying existing crops and contributing to sustainable agriculture.

Made available in DSpace on 2022-05-01T08:45:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Distributions of aquatic macrophyte species are commonly associated with water chemistry characteristics. However, other environmental factors that can lead to the occurrence of aquatic plants in lotic ecosystems, such as dynamic habitats linked to the surrounding landscape, have been underestimated. This study aims to evaluate landscape features that may influence the occurrence of species of euhydrophyte aquatic macrophytes in a tropical river basin. We assessed the occurrence of the following seven species: Egeria densa, Cabomba furcata, Potamogeton pusillus, Potamogeton polygonus, Utricularia foliosa, Pistia stratiotes and Salvinia molesta. We also measured environmental variables related to three spatial scales, local (limnological), channel and riparian landscape, along 25.5 Km of the Itanhaém River basin (São Paulo, Brazil). We found that local (limnological) and channel characteristics were important variables in determining the occurrence of aquatic macrophyte species while the landscape scale had little influence on species composition. Channel depth and margin slope were especially relevant abiotic variables in explaining the occurrence of four of the species but not P. pusillus, P. polygonus and U. foliosa. Our results highlight the importance of channel morphology for understanding aquatic plant occurrence and community composition in tropical rivers. Laboratório de Ecologia Aquática Departamento de Ecologia Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” Grupo Ecologia Monitoramento e Uso Sustentável de Áreas Úmidas Instituto Nacional de Pesquisas da Amazônia Laboratório de Hidrologia Florestal Departamento de Ciências Florestais Escola Superior de Agricultura Luiz de Queiroz Instituto de Ciências Biológicas Coordenação de Ecologia Universidade de Brasilia, DF Laboratório de Ecologia Aquática Departamento de Ecologia Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho”

Heterophylly is the development of different leaf forms in a single plant depending on the environmental conditions. It is often observed in amphibious aquatic plants that can grow under both aerial and submerged conditions. Although heterophylly is well recognized in aquatic plants, the associated developmental mechanisms and the molecular basis remain unclear. To clarify these underlying developmental and molecular mechanisms, we analyzed heterophyllous leaf formation in an aquatic plant, Callitriche palustris. Morphological analyses revealed extensive cell elongation and the rearrangement of cortical microtubules in the elongated submerged leaves of C. palustris. Our observations also suggested that gibberellin, ethylene, and abscisic acid all regulate the formation of submerged leaves. However, the perturbation of one or more of the hormones was insufficient to induce the formation of submerged leaves under aerial conditions. Finally, we analyzed gene expression changes during aerial and submerged leaf development and narrowed down the candidate genes controlling heterophylly via transcriptomic comparisons, including a comparison with a closely related terrestrial species. We discovered that the molecular mechanism regulating heterophylly in C. palustris is associated with hormonal changes and diverse transcription factor gene expression profiles, suggesting differences from the corresponding mechanisms in previously investigated amphibious plants., We identified the key gene set and the hormonal control basis for the drastic heterophylly of an aquatic plant, Callitriche palustris.

Additional active ingredients are needed for use in aquatic systems to respond to new threats or treatment scenarios, enhance selectivity, reduce use rates, and mitigate the risk of herbicide resistance. Florpyrauxifen-benzyl is a new synthetic auxin developed for use as an aquatic herbicide. A study was conducted at North Carolina State University in which 10 µg L−1 of 25% radiolabeled florpyrauxifen-benzyl was applied to the isolated shoot tissue of 10 different aquatic plant species to elucidate absorption and translocation patterns in these species. Extremely high levels of shoot absorption were observed for all species, and uptake was rapid. Highest shoot absorptions were observed for crested floatingheart [Nymphoides cristata (Roxb.) Kuntze] (A192 = 20 µg g−1), dioecious hydrilla [Hydrilla verticillata (L. f.) Royle] (A192 = 25.3 µg g−1), variable watermilfoil (Myriophyllum heterophyllum Michx.) (A192 = 40.1 µg g−1), and Eurasian watermilfoil (Myriophyllum spicatum L.) (A192 = 25.3 µg g−1). Evidence of translocation was observed in all rooted species tested, with the greatest translocation observed in N. cristata (1.28 µg g−1 at 192 h after treatment). The results of this study add to the growing body of knowledge surrounding the behavior of this newly registered herbicide within aquatic plants.

Saudi Arabia has no permanent lakes or rivers but has wet meadows, which are desert wetlands temporarily formed due to the seasonal rainfall. This work investigates the environmental variables' impact on the vegetation pattern in the desert-wetland ecosystem in Taif highlands. Forty-one stands were randomly selected representing three main habitats (wet meadows, slopes, and terraces) to study their floristic features and vegetation analysis. A total of 142 species were recorded belonging to 111 genera and 45 families in the desert wetlands of Taif Province. About 64.1% were natural plants, while 25.4% were segetal weeds, 7.7% were aquatic plants, and 2.8% were plants that escaped from cultivation. Therophytes dominated over the other life forms, and mono-regional taxa were the dominant chorotype. Multivariate analysis of the recorded plants produced eight vegetation groups; four of them (A: Potamogeton nodosus-Nasturtium officinale, B: Lemna gibba-Leptochloa fusca, C: Typha domingensis- Xanthium strumarium and D: Conyza stricta- Cyperus longus) represented the wet meadows, while two (E: Acacia gerrardii- Commicarpus plumbagineus and H: Osteospermum vaillantii- Eragrostis Pilosa) for slopes and other two (F: Argemone ochroleuca-Cyperus rotundus and G: Pulicaria undulata- Solanum incanum) for the desert terraces. The vegetation zonation was clear, which started from real aquatic species in the wet meadows passing through mixed vegetation in the slopes and ended with proper xerophytic vegetation in the terraces. Conyza stricta- Cyperus longus community had the highest species diversity, while that of Potamogeton nodosus-Nasturtium officinale had the lowest. The principal component analysis indicated that HCO3, NO3, Mg, Cl, Ca, and pH values were the most effective soil variable. The presence of several segetal weeds suggests the alteration of the natural status of the desert-wetland ecosystem, and thus the conservation of these natural habitats becomes urgent.

The article describes the Dengizkul cadastre, the fertility of phytoplankton of lake water in laboratory conditions, the fertility and fluidity of higher aquatic plants and their significance. Information on the cultivation and use of plant species rich in physiological substances as food for herbivorous fish is presented.

Cytogenetic studies on four species of vascular coastal and water plants from Russian Far East are presented. During the present investigation the next chromosome numbers have been revealed: Gypsophila pacifica (2 n = 34), Allium sacculiferum (2 n = 32), Mertensia maritima (2 n = 24), and Nelumbo komarovii (2 n = 16). Unusual chromosome numbers for these species have not been noted but it was the first case of karyological studies of Nelumbo komarovii from the Jewish Autonomous Region and most northern habitat. The number of nucleoli in interphase nuclei of these species was counted. Interphase nuclei of studied species contain 1–4 nucleoli except in A. sacculiferum so far which have 1–2 nucleoli per cell. Different points of view on polyploidy of studied species are discussed.

Water hyacinth (Eichhornia crassipes), a free-floating aquatic macrophyte belonging to the family Pontederiaceae, is invasive in tropical and subtropical areas worldwide. Using brightfield and epif...

Studies of plant phenology have been performed predominantly with terrestrial species and rarely so with aquatic communities. Such plants are fundamental for the aquatic ecosystems, representing a valuable source of resources when they are scarce in terrestrial environments for the fauna. Studies of phenology help to understand the reproduction rhythms of plant communities and provide fundamental support to management and conservation. This study aimed to describe the reproductive phenology of 15 species of aquatic plants and determine how it is related to climatic factors and physicochemical variables of water. Plants were collected every 15 days throughout a single year, from two ponds in the Cerrado-Pantanal ecotone, Central-West Brazil. Species were observed in flower and fruit throughout the year with varying phenophases among life forms (amphibious, emergent, rooted, floating and rooted submerged). Photoperiod stood out among climatic variables for flowering and fruiting times. Phenophases were explained by climatic factors, as well as by physicochemical variables of the water. Nitrogen and pH were the variables most related to the highest number of phenophases of different life forms. Such information is relevant to understanding how physicochemical alterations to water by pollution, eutrophication and siltation, among others, can change the phenology of aquatic macrophytes.

Until the mid-XX century, little awareness on the ecological services or socio-environmental problems and benefits related to aquatic plants culminated in bottlenecks on their natural history, especially for the Neotropics. In this context, Acta Botanica Brasilica (ABB) organized this special issue to promote the advancement of knowledge on this ecological group in the Neotropics, supported by Sociedade Botânica do Brasil’s group of aquatic plants specialists. We selected and evaluated manuscripts gathering unprecedented findings, resulting from studies on aquatic plants, with little investigated or documented approaches, such as the improper use of methodological paradigms and aspects of biogeography, ecophysiology, morphoanatomy, structuration of communities, functional ecology, and human use. Here we present a synthesis of these reports’ findings that shall contribute to deepening the knowledge on the natural history, sustainable use, and conservation of aquatic plants and guide future research, mainly in Neotropical aquatic ecosystems. The publication of special issues on themes with insufficient knowledge to Science can reduce such gaps and expand the journal’s perspectives. Therefore, we believe that this special issue of ABB will boost the understanding of aquatic plants’ natural history as much as incentivizing journals with specific scopes of the area of Plant Biology to similar initiatives.

Amazon wetlands are among the most vulnerable ecosystem to be impacted by climate change, which may increase the frequency of extreme droughts and floods. We used Eichhornia crassipes and Pistia stratiotes, two abundant aquatic plants in the Amazon floodplains, to evaluate the effects of combined temperature and [CO2] increase on growth, physiology and ecological interactions. Individual and paired plants were deposited for three weeks in a microcosm under four IPCC scenarios: control (current temperature/CO2), mild (control + 1.5 ºC, 200 ppm CO2), intermediate (control + 2.5 ºC, 450 ppm CO2) and extreme (control + 3.5 ºC, 850 ppm CO2). P. stratiotes died after three weeks in the intermediate and extreme treatments; E. crassipes experienced no mortality or change in any of the measured variables during the same period. P. stratiotes reduced root length in the mild treatment and reduced total dry biomass in intermediate and extreme treatments, revealing less tolerance to climate change. Ecological interactions between the two species changed with increasing [CO2] and temperature neutral interaction changed to facilitation for E. crassipes, while competitive interaction changed to neutral for P. stratiotes. Global climate change may alter the composition, biomass and ecological interactions of Amazonian aquatic plant species.

Arbuscular mycorrhizal fungi (AMF) colonize the roots of numerous aquatic and wetland plants, but the establishment and functioning of mycorrhizal symbiosis in submerged habitats have received only little attention. Three pot experiments were conducted to study the interaction of isoetid plants with native AMF. In the first experiment, arbuscular mycorrhizal (AM) symbiosis did not establish in roots of Isoëtes echinospora and I. lacustris, while Littorella uniflora roots were highly colonized. Shoot and root biomass of L. uniflora were, however, not affected by AMF inoculation, and only one of nine AMF isolates significantly increased shoot P concentration. In the second experiment, we compared colonization by three Glomus tetrastratosum isolates of different cultivation history and origin (aquatic versus terrestrial) and their effects on L. uniflora growth and phosphorus nutrition under submerged versus terrestrial conditions. The submerged cultivation considerably slowed, but did not inhibit mycorrhizal root colonization, regardless of isolate identity. Inoculation with any AMF isolate improved plant growth and P uptake under terrestrial, but not submerged conditions. In the final experiment, we compared the communities of AMF established in two cultivation regimes of trap cultures with lake sediments, either submerged on L. uniflora or terrestrial on Zea mays. After 2-year cultivation, we did not detect a significant effect of cultivation regime on AMF community composition. In summary, although submerged conditions do not preclude the development of functional AM symbiosis, the contribution of these symbiotic fungi to the fitness of their hosts seems to be considerably less than under terrestrial conditions.

Radial oxygen loss is a physical phenomenon that occurs naturally in aquatic plants. Typha domingensis was chosen as a model plant because it possesses basic morphological characteristics, such as a stem (rhizome) that produces leaves and adventitious roots, which are present in many aquatic plants. This study aimed to evaluate the following: the relevance of the anatomy of T. domingensis on gas diffusion among organs; the influence of plant parts on radial oxygen loss; the role of catalase in radial oxygen loss; and the proposition of a novel explanation for the downward diffusion of oxygen through the organs of this aquatic macrophyte and into the environment. Typha domingensis plants were cultivated in a greenhouse under different conditions: plants with intact leaves, plants with leaves cut in half, and plants without leaves. Furthermore, we evaluated the percentage of aerenchyma in different vegetative organs, the minimum pressure required for radial oxygen loss, the daily variations of dissolved oxygen, and the roots' catalase activity. The results demonstrated that certain cellular features contributed to decreased oxygen diffusion among the organs, specifically, those found in the leaf-rhizome and root-rhizome interfaces as well as the suberin and lignin layers in these regions. Additionally, our experiments with a catalase activator and inhibitor validated that a significant amount of the oxygen released in radial oxygen loss could not, in fact, be exclusively supplied by the atmosphere. Thus, a complementary model is proposed in which catalase activity is an important component of radial oxygen loss.

Monoecious and dioecious forms of the submerged aquatic plant hydrilla, Hydrilla verticillata (Hydrocharitaceae) are invasive weeds in the United States. Monoecious hydrilla is expanding northward ...

Genetic assays to identify herbicide-resistant plants are a promising tool to reduce herbicide failures. However, the genetic basis of herbicide resistance is frequently unknown. In clonal weed species, DNA fingerprinting could be a useful tool to identify known resistant versus susceptible genets (clones) that occur in multiple locations, without an immediate need for understanding the genetic mutation(s) conferring resistance. Eurasian watermilfoil (Myriophyllum spicatum L.) and hybrids with native northern watermilfoil (Myriophyllum spicatum × Myriophyllum sibiricum Kom.) are mostly clonal invasive aquatic plants, and the same clones can be found in multiple waterbodies. Previously, a clone was confirmed as resistant to the commonly used herbicide fluridone, and a recent genetic survey in Michigan identified this genotype (MG-237) in at least seven other lakes. We hypothesized that MG-237 collected from different lakes would also exhibit fluridone resistance. However, MG-237 may have accumulated resistance mutations at different times during its spread across Michigan, resulting in fluridone-resistant and fluridone-susceptible MG-237 clones distributed in different lakes. We used a herbicide assay to test the response of several accessions, including MG-237 accessions from multiple lakes, to the Michigan operational rate of 6 µg L−1 fluridone. We found that all accessions of MG-237 exhibited resistance to 6 µg L−1 fluridone. A second genotype (MG-377) was also resistant to 6 µg L−1 fluridone. The rest of the accessions were found to be significantly injured by 6 µg L−1 fluridone. Our results suggest that 6 µg L−1 fluridone would not effectively control waterbodies dominated by MG-237 or MG-377, whereas waterbodies dominated by the other genotypes in our study would likely be controlled. Although more studies are needed to identify the variation in sensitivity of the accessions tested here and the genetic basis of fluridone resistance in Myriophyllum, our results suggest that multilocus genotype data may be an effective tool to identify and track herbicide-resistant genotypes of Myriophyllum in the short term.

Hairy root cultures are often used to produce valuable metabolites. They are grown on sucrose-rich medium, which is highly susceptible to contamination. Trapa natans is a unique plant with photosynthesizing roots. It is a promising object to obtain photoautotrophic hairy root culture. Protocols for transformation of this species are yet unknown. We report that hairy roots can be induced in aquarium and in vitro cultures of T. natans by agrobacterium-mediated and biolistic transformation. 64 roots were induced by Agrobacterium rhizogenes strain 15834, two roots were obtained using strain K599. Strain A4 was not effective. Biolistics with either amplicons of rol genes and 1301 pCAMBIA plasmid carrying rol genes resulted in the formation of six roots. All these roots contained chloroplasts. This achievement opens a prospect for genetic transformation of T. natans and use of its green photosynthesizing hairy root cultures in production of bioactive substances and in phytoremediation. Protocols for the Agrobacterium-mediated and biolistic transformation of Trapa natans to induce hairy roots have been developed for the first time. All induced roots contained chloroplasts.

Aims Many wetlands are polluted with both nutrients and toxic metals and vegetated largely by clonal plants. We hypothesized that eutrophication and clonal integration can increase phytoremediation of toxic metal pollution by increasing plant growth, even under the stress imposed by toxicity. Methods To test this hypothesis, single ramets of the common, widespread, floating, stoloniferous plant Pistia stratiotes L., were grown for 42 days at two levels of nutrient availability with and without 0.6 mg L−1 cadmium. Ramets were either severed from their vegetative offspring to prevent clonal integration or left connected, and severed offspring were either removed to eliminate intraclonal competition or left in place. Important Findings Plants subjected to cadmium addition accumulated almost twice as much dry mass if given the higher nutrient level, due mainly to a doubling of the number of clonal offspring. Severance had little effect on the final mass of the parent plus offspring ramets. Removing offspring following severance had no effect on the final mass of the parental ramet in the presence of added cadmium, but it did increase the final mass of the parent in the absence of cadmium. These results support the hypothesis that eutrophication can increase remediation of toxic metal pollution by aquatic macrophytes but provided no evidence that clonal integration can affect remediation. Species such as P. stratiotes may help remediate co-pollution of wetlands with toxic metals and nutrients, and fragmentation of clones may not affect their remediation capacity.

The biomorphological features of Hydrilla verticillata (L. fil.) Royle in tropical and temperate regions of the Eurasian part of the geographical range have been studied. The shoot system is long-growing and sympodial, consisting of (annual)oligoennial monopodial shoots of main and subordinate orders. The number of leaves per node; shape, length, and width of leaf blade; branching peculiarities; and the length of the internode are the most variable signs. Hydrilla verticillata is a perennial (vegetatively oligoennial) polycarpic rooting long-shoot high turion-tuber vegetative–mobile hydrophyte. The flexibility of biomorphs in different biotypes is manifested by the duration of shoot ontogenesis and by a change in the ratio of the specialized vegetative diasporas. Turions and tubers are the two alternative models for maintaining the population.

The micromophology of relict hydrophytes Brasenia schreberi J. F. Gmel. (Cabombaceae), Nuphar japonica DC. (Nymphaeaceae), and Nelumbo komarovii Grossh. (Nelumbonaceae) has been studied based on material from the Lower Amur region. Detailed descriptions of the anatomical structure of leaves in contact with the air are given. A common feature was the dorsoventrality of the leaf blade and the atactostelia of leaf petioles. The development of a system of diffuse intercellular spaces and aerenchyma and a reduction of xylem in the studied species are effective adaptations to the aquatic habitat. It was assumed that the studied species was preserved in the south of the Russian Far East due to maximum protection during the winter. Compensatory adaptations in the microstructure of the leaf are the development of a multifunctional parenchyma, an increased content of secondary metabolites and hydrophobic compounds, and reinforced leaves.

Environmental DNA (eDNA) analysis offers a promising tool for rapid and early detection of aquatic plant invasive species, but currently suffers from substantial unknowns that limit its wid...

Environmental DNA (eDNA) metabarcodes allow for the simultaneous detection of multiple taxa if the barcode regions meet several key requirements including conserved primer‐binding sites, interspecific variability that exceeds intraspecific variability, and relatively short amplicons. Currently, there are no established metabarcoding assays for aquatic vascular plants, which could limit biodiversity assessments and the early detection of alien species. We used a combination of novel and pre‐existing primers to generate eDNA metabarcodes from three gene regions that are commonly used for plant barcoding: two regions of chloroplast DNA (rbcL and matK) plus a segment of an internal transcribed spacer (ITS2). We optimized the assay on a mock community of 25 known species and then applied it to wild samples collected from two waterbodies in southern Ontario, Canada (Black River and Seymour Lake). Our novel rbcL primers, which amplify a fragment of ~220 bp, provided the most comprehensive description of the mock community, identifying all but one of the taxa to species or genus. In addition, after pooling data from five sites within each sampled waterbody, metabarcodes generated by this same primer pair identified more taxa than all other primer pairs; more specifically, 20 and 26 taxa were identified from Black River and Seymour Lake, respectively, to species or genus. Across the two sites, nine of the identified taxa are alien invasive aquatic plants. Five of these invasive species have no previous reports from our sites, and in some cases have no known established Ontario populations; our data therefore suggest an urgent need to increase surveillance for these aliens. Overall, our study showed that eDNA metabarcoding with a novel rbcL primer pair provides a cost‐effective method for simultaneously detecting multiple aquatic vascular plant taxa and is a valuable tool for the early detection of invasive species.

is a free-floating hydrophyte fern grown in temperate and tropical regions. The specialized dorsal leaves of the fern possess cavity that harbors cyanobacteria capable of fixing atmospheric nitroge...

Macrophytes play a key role in stabilizing clear‐water conditions in shallow freshwater ecosystems. Their populations are maintained by a balance between plant grazing and plant growth. As a freshwater snail commonly found in shallow lakes, Radix swinhoei can affect the growth of submerged macrophytes by removing epiphyton from the surface of aquatic plants and by grazing directly on macrophyte organs. Thus, we conducted a long‐term (11‐month) experiment to explore the effects of snail density on macrophytes with distinctive structures in an outdoor clear‐water mesocosm system (with relatively low total nitrogen (TN, 0.66 ± 0.27 mg/L) and total phosphorus (TP, 36 ± 20 μg/L) and a phytoplankton chlorophyll a (Chla) range of 14.8 ± 4.9 μg/L) based on two different snail densities (low and high) and four macrophyte species treatments (Myriophyllum spicatum, Potamogeton wrightii, P. crispus, and P. oxyphyllus). In the high‐density treatment, snail biomass and abundance (36.5 ± 16.5 g/m2 and 169 ± 92 ind/m2, respectively) were approximately twice that observed in the low‐density treatment, resulting in lower total and aboveground biomass and ramet number in the macrophytes. In addition, plant height and plant volume inhabited (PVI) showed species‐specific responses to snail densities, that is, the height of P. oxyphyllus and PVI of M. spicatum were both higher under low‐density treatment. Thus, compared with low‐density treatment, the inhibitory effects of long‐term high snail density on macrophytes by direct feeding may be greater than the positive effects resulting from epiphyton clearance when under clear‐water conditions with low epiphyton biomass. Thus, under clear‐water conditions, the growth and community composition of submerged macrophytes could be potentially modified by the manual addition of invertebrates (i.e., snails) to lakes if the inhibitory effects from predatory fish are minor., In the study, we conducted a long‐term (11‐month) experiment to explore the effects of snail density on macrophytes with distinct structures in an outdoor clear‐water mesocosm based on different snail density and macrophyte species treatments. Our results indicated that high snail density reduced total biomass of submerged macrophytes and ramet number. In addition, plant height and plant volume inhabited showed species‐specific responses to snail densities.

Bioassays based on aquatic plants are a convenient tool for studying the quality of bottom sediments. One of the stages in the development of a bioassay is the selection of optimal growth conditions for indicator plants in a model test system. Response of indicator physiological endpoints of Canadian waterweed (Elodea canadensis) to light flux density was investigated to determine optimal irradiance level in a “water – sediment” model system, proposed previously for contact bioassay of natural bulk bottom sediments. Based on the response of shoot and root growth (length and weight), and concentration and ratio of photosynthetic pigments (chl. a, chl. b, and carotenoids) of Elodea to the change of light flux density, no limitation or inhibition of growth and photosynthesis of Elodea was revealed at light flux density from 56 to 143 μmol quanta ∙ m-2 ∙ s-1. Hence, the level of irradiance within this range can be recommended for use in the experimental system proposed for bioassay of bulk bottom sediments using E. canadensis as an indicator

Wolffia arrhiza (L.) Horkel ex Wimm. is an aquatic plant belonging to the Lemnaceae family. It does not have leaves, stems, and roots, flowers rarely occur, while body size can reach 1 mm of width and 1.3 mm of length. The present study demonstrates the endogenous level of isoprenoid-derived phytohormones and their changes under the influence of different cadmium (Cd) concentrations (0.1, 1, 10, and 100 µM). A liquid chromatography quadrupole-time-of-flight mass spectrometry analysis indicated the presence of abscisic acid, eight brassinosteroids (6-deoxocastasterone, 6-deoxotyphasterol, cathasterone, typhasterol, castasterone, 24-epicastasterone, brassinolide, and 28-homobrassinolide), seven free bases of cytokinins [trans-zeatin (tZ), cis-zeatin (cZ), dihydrozeatin (DHZ), N6-isopentenyladenine, N6-isopentenyladenosine, ortho-topolin, and meta-topolin], eight conjugates of cytokinins (tZ riboside, tZ-9-glucoside, tZ-7-glucoside, tZ-O-glucoside riboside, cZ-9-glucoside, DHZ riboside, DHZ-O-glucoside, and N6-isopentenyladenosine-7-glucoside) and gibberellic acid (GA3) in this duckweed. The level of phytohormones in plants treated with Cd has changed, e.g., the ABA level increased while GA3 decreased. Whereas the amount of BRs and CKs was different in Cd dose-dependent manner. Besides, it is worth noting that the distribution of 25 various phytohormones in the Wolffia arrhiza is reported for the first time.

Aquatic plants have adapted to reside in water and extensively get used for human benefits. The nutritive value and bio-fertilizing efficiency of Azolla pinnata (Azolla) and Spirodela polyrhiza (Duckweed) were estimated in the present investigation. Both Azolla and Duckweed were observed to be high in nutritive values and rich in protein content, carotenoids, amino acids, anti-oxidants, starch and fibres. However, Azolla pinnata was observed to have prime nutritional qualities than Spirodela polyrhiza. Significant increase in growth of test plants (Vigna unguiculata) in terms of shoot and root length under the treatment with 10% and 20% of cellular extracts as compared to control condition confirmed their efficacy as bio-fertilizers even in low concentration of 20% extract. This study showed that both Azolla pinnata and Spirodela polyrhiza can be useful for quality nutrient supplement for humans as well as animals and can be applied as efficient environment-friendly and economic bio-fertilizers for plant growth.

Cobalt is an essential trace metal and plays a pivotal role in the growth of all living organisms. The exposure of cobalt in the aquatic environment is ubiquitous via both natural and anthropogenic activities. The present study was carried out to investigate the accumulation response of macrophyte Hydrilla verticillata (L.f.) Royle towards the cobalt exposure at different concentrations (1, 25, 50, 75 and 100 µM) for seven days. The results showed that the cobalt accumulation increased in treated H. verticillata (L.f.) Royle with increase in concentration. The Bioconcentration factor (BCF) values were high in plants exposed to higher concentration of cobalt. Increase in growth (shoot length) and pigments (chlorophyll a, b and total chlorophyll) were detected at 25 µM cobalt concentration, whereas the growth and pigments were declined in 50, 75 and 100 µM. There was no significant difference in the carotenoid content between control and treated plant. Antioxidant enzymes (superoxide dismutase, catalase, and peroxidase) were increased at higher concentrations of cobalt. The results indicated that the decline in growth and pigments, and an increase in antioxidant enzyme activities, were triggered by the accumulation of cobalt in the plant. These observations suggest that H. verticillata (L.f.) Royle is well equipped to accumulate low concentration of cobalt in tissues to increase its growth and detoxify ROS generation. The BCF results indicate the efficiency of using H. verticillata (L.f.) Royle as a phytostabilizer.

This study intended to develop a significant in vitro regeneration protocol for sustainable propagation, conservation and re-establishment of critically endangered aquatic plant species Crinum malabaricum Lekhak & Yadav (Malabar river lily). This plant is the natural source of galanthamine, the drug to treat Alzheimer’s disease. We present a scientific understanding, emphasizing the use of twin scales (separated from the large parent bulb) in direct regeneration of new shoots and proliferation of bulblets assisted by nutrients supply. The meristematic region of the bulb plate, present between the scales was activated using cytokinins to produce shoots (maximum 12 shoots per twin scale) on full strength Murashige and Skoog’s (MS) medium augmented singularly with 2.0 mg L−1 6-benzylaminopurine (BAP). Upon subculturing of shoots on diverse concentrations of plant growth regulators (BAP and IAA/NAA), BAP alone at 2.0 mg L−1 was served optimum for the better proliferation of shoots (53 shoots). The regenerated shoots were rooted in vitro on half strength MS medium fortified with various types of auxins. Highest number of roots (11.6 within 4 weeks) and bulblets (after 3 months) resulted with 1.0 mg L−1 Indole-3-butyric acid (IBA) under in vitro conditions. The rooted plants were hardened in the greenhouse and finally transferred to the natural stream with 83% survival rate. The SCoT (start codon targeted) and ISSR (inter simple sequence repeats) marker analysis of in vitro raised and mother plants confirmed the genetic stability of tissue cultured plants and the reliability of present protocol for C. malabaricum. It is the foremost report on in vitro regeneration and genetic fidelity analysis for restoration of this critically endangered aquatic plant using twin scale technique. The study could help in ex situ conservation, reintroduction and restoration of C. malabaricum population in its natural habitat. Crinum malabaricum is a critically endangered aquatic plant species and natural source of galanthamine. It is endemic to India and about 1000 plants only available in a private estate in the Western Ghats of India. In vitro regeneration protocol has been developed utilizing twin scales for conservation of this plant. It is the first report on effective in vitro propagation and bulblets formation in C. malabaricum.

This work purpose was to find the impact of Pistia stratiotes L., 1753 - a new species on the territory of Ukraine, on the vitality of other free-floating hydrophytes so-called pleuston- Salvinia natans (L.) All., 1785, S. laevigatum (Humb. and Bonpl. ex Willd.) Heine, 1968, to determine the degree of stability and competitiveness of these species for resources in natural ecosystems relatively to the undesirable species. To find out the influence of P. stratiotes on other free-floating on the water surface plant species which compete for elements of nutrition among each other, we have investigated changes in the content of photosynthetic pigments in S. laevigatum and S. natans, which were exhibited with P. stratiotes for 14 days. Besides changes in water indices, oxygen content, mineralization and pH, were measured.

Background: Microorganisms from understudied habitats have been shown to be an important source of novel bioactive compounds. Endophytes constitute an underexplored group of microorganisms, of which those from aquatic plants have been even less studied. Nelumbo nucifera (lotus) is an aquatic plant with medicinal properties. A screening program for endophytes from N. nucifera by our research group resulted in many microbial isolates, of which isolate L-003 was a promising candidate, exhibiting antimicrobial and antioxidant activities. Objectives: The major objectives were to characterize the endophyte L-003 for its antimicrobial and antioxidant properties, identify the constituent bioactive compounds by GC-MS and characterize their activities further using in silico software. Methods: L-003 was identified by PIBWin software. Antimicrobial activity of the aqueous and organic extracts of culture supernatant of L-003 was checked against a panel of bacteria and fungi. Since the ethyl acetate extract showed the best antimicrobial activity, it was further characterized by thin layer chromatography, an activity confirmed by bioautography and purified by column chromatography. Total antioxidant capacity was assayed by standard techniques. Partially purified metabolite fingerprints were identified by GC-MS analysis. Results: Based on morphological and biochemical analyses, isolate L-003 was identified as belonging to Streptococcus sp. All the organic solvent extracts showed antimicrobial activity. Ethyl acetate extract showed maximum antimicrobial activity against all selected targets and exhibited antioxidant activity too, though butanol and aqueous extracts showed higher antioxidant activity. Two compounds, Acetic acid,-hydroxy, methyl ester and Disulfide, dipropyl, were identified by GC-MS in the metabolite fingerprint. These compounds showed differences in observed and calculated retention indices and could, therefore, be novel. In silico activity, characterization confirmed the antimicrobial and antioxidant properties attributed to these compounds. Conclusion: This is the first study reporting metabolite fingerprinting, identification and characterization of bioactive compounds from an endophytic isolate of Nelumbo nucifera. We conclude that endophytes from aquatic plants could be prospective sources of bioactive compounds, in this case with antimicrobial and antioxidant activities.