Search Results (35)

Although the effects of human disturbance on population genetic variation in plants have been widely studied, little attention has been paid to the impact of environmental changes on genetic dynamics after the implementation of conservation measures. Previously, freshwater Caohai Lake, famous for its abundant aquatic plants and birds, was strongly disturbed by tourism and other human activities; however, strict protective measures have been implemented since 2019. Therefore, the lake provides a suitable natural sampling ecosystem for investigating genetic variation changes following the implementation of conservation measures. Samples of cosmopolitan aquatic Ceratophyllum demersum were collected in 2019 and 2021, and they were analyzed using microsatellite primers. Our results show the presence of considerable genetic diversity in the C. demersum Caohai population. Although human disturbance decreased, the impact of natural disturbances, such as water flow and bird activities, persisted and may have increased. For C. demersum, water flow may cause vegetative propagules of different genotypes to pool in the downstream area of the lake. At sites with a very rich diversity of birds, increasing bird activities may augment the advantage of competitive clones in communities. Therefore, the continuous monitoring of the population’s genetic variation and the impact of related environmental factors is required for the efficient management of the lake ecosystem. Full article

The effects of toxic and non-toxic Microcystis aeruginosa on the Ceratophyllum demersum–Scenedesmus obliquus system were simulated in the laboratory, and some parameters in relation to these organisms were measured. In this experiment, C. demersum increased the biomass of S. obliquus, and both toxic and non-toxic M. aeruginosa significantly inhibited the colony formation of S. obliquus and inhibited the promotion of S. obliquus biomass. On the 14th day, the soluble polysaccharide content of C. demersum decreased when it was coexisted with S. obliquus, but it rose again because of M. aeruginosa, which significantly increased the protein content of C. demersum. The species composition and diversity of epiphytic microorganisms also vary with different treatments. Proteobacteria is dominant in all the groups, especially in the Toxic_SMC group. In addition, bacteria that can degrade organic pollutants are more abundant in Toxic_SMC group. This study focuses on the defense response of S. obliquus induced by C. demersum under the pressure of toxic or non-toxic M. aeruginosa and evaluates the changes to C. demersum and its epiphytic microorganisms, which provides insights for the study of aquatic plant–algae integrated action systems in eutrophic or cyanobacterial blooms. Full article

Macrophytes often live in fluvial backwaters that have a variety of hydrological connections to a main river. Since the ability of these plants to adapt to changing environments may depend on the genetic diversity of the populations, it is important to know whether it can be influenced by habitat characteristics. We examined the microsatellite polymorphism of the submerged macrophyte Ceratophyllum demersum from various backwaters and showed that the genetic diversity of this plant clearly reflects habitat hydrological differences. The greatest genetic variability was found in a canal system where constant water flow maintained a direct connection between the habitats and the river. In contrast, an isolated backwater on the protected side of the river had the lowest plant genetic diversity. Oxbows permanently connected to the branch system with static or flowing water, and former river branches temporarily connected to the main bed contained populations with moderately high or low genetic variability. The results demonstrate that habitat fragmentation can be a result not only of the loss of direct water contact, but also of the lack of flowing water. Adverse hydrological changes can reduce the genetic diversity of populations and thus the ability of this macrophyte to adapt to changing environments. Full article

Ecological restoration in dredging areas has attracted increasing attention. The reconstruction of a submerged plant ecosystem is an important method for aquatic ecosystem restoration. This study has systematically investigated the effect of biochar-improved sediment on the plant growth and decontamination efficiency of a constructed ecosystem. Microbial community composition and structure in the sediment were detected. The results showed that a supplement of 20 mg/g of biochar significantly increased the biomass of the submerged plants compared with other doses (0, 10, and 40 mg/g). The biomass and chlorophyll content were significantly inhibited by supplementing 40 mg/g of biochar. In the Ceratophyllum demersum L. system, TP and NH₄⁺-N concentrations were significantly lower after treatment with 20 mg/g of biochar compared to other doses. In Vallisneria spiralis L. and Hydrilla verticillata (L. f.) Royle systems, NH₄⁺-N, TP, and DO concentrations were significantly different among different biochar treatments. In general, 20 mg/g of biochar improved water quality in different submerged plant systems, while 40 mg/g of biochar had adverse effects on water quality, such as higher NH4⁺-N and TP concentrations. The dominant microbial community included Proteobacteria, Acidobacteria, Chloroflexi, Actinobacteriota, and Bacteroidota. The structure and function of microbial communities were different among submerged plants and biochar treatments. Our results proposed a construction strategy of submerged plants in the dredging area. Full article

Macrophytes and cladocerans represent the main antagonistic groups that regulate phytoplankton biomass; however, the mechanism behind this interaction is unclear. In laboratory conditions, we separately evaluated the effects of three submerged macrophytes (Ceratophyllum demersum, Myriophyllum aquaticum, and Stuckenia pectinata), as well as their exudates, and plant-associated microbiota (POM < 25 µm) + exudates on the population growth of Daphnia cf. pulex and Simocephalus cf. mixtus. Living Ceratophyllum, exudates, and POM < 25 µm + exudates exhibited the most robust positive effects on Simocephalus density and the rate of population increase (r). Subsequently, we examined the effects of Ceratophyllum on the filtration and feeding rates of Simocephalus and Daphnia, revealing significant (p < 0.001) promotion of filtration and feeding in Simocephalus but not in Daphnia. To elucidate the specific effects of this macrophyte on Simocephalus demography, we assessed selected life table variables across the same treatments. The treatments involving exudates and living Ceratophyllum resulted in approximately 40% longer survivorship and significantly (p < 0.01) enhanced fecundity. Our findings indicate that exudates from submerged macrophytes positively influence Simocephalus demography by increasing filtration rates, survivorship, and fecundity. This synergy suggests a substantial impact on phytoplankton abundance. Full article

The effects of submerged plant-induced calcium and phosphorus coprecipitation on the phosphorus cycle in aquatic environments and interspecific differences are still unclear. Herein, we selected Ceratophyllum demersum L. and Potamogeton crispus L. to construct a sediment–water-submerged plant system. We examined how phosphorus concentrations in the water, sediment, and plant ash changed over time with different phosphorus and calcium treatments and explored the effects of photosynthesis-induced calcium and phosphorus coprecipitation on water’s phosphorus cycle and variations between different submerged plant species. The main results were as follows: (1) The phosphorus reduction in the P. crispus system was less than that in the C. demersum system. (2) P. crispus had higher total ash phosphorus (TAP) values than C. demersum. (3) The sediment total phosphorus (STP) and its fractions with P. crispus were most affected by phosphorus concentration while those with C. demersum were most affected by time. Overall, the two submerged species exhibited different calcium and phosphorus coprecipitation levels and had distinct effects on the water-to-phosphorus cycle. When submerged plants are introduced to reduce and stabilize the phosphorus levels, plant interspecific differences in their induced calcium and phosphorus coprecipitation on water and phosphorus cycling must be fully assessed. Full article

Aerobic composting is one of the methods for the resource utilization of submerged plant residues. This study investigated the effects of biochar, wetland sediments and microbial agents added individually or combined on the humification process, lignocellulose degradation and microbial communities during Ceratophyllum demersum and Potamogeton wrightii composting. The results showed that the addition of wetland sediment and biochar was found to significantly elevate the composting temperature and humification of compost products. The average content of lignin in wetland sediment and/or biochar treatments was 12.2–13.5%, which was higher than the control group (10.9–11.45%). Compared with the organic matter (19.4%) and total nitrogen concentration (35.3%) of compost treated with complex microbial agent treatments, the homemade microbial agents significantly increased the values by 22.1% and 41.0%, respectively. By comparing the differences in microbial communities among different treatments, the sediments and homemade agents demonstrated greater increases in activity and diversity of lignocellulose degradation-related microbes, especially for Truepera and Actinomarinale. Humus component and temperature were the most critical parameters influencing the changes in the bacterial community. Based on these results, a combination of biochar and homemade agents was a promising additive for an effective composting strategy, and sediment was identified as a potential control of bacterial diversity in wetland plant compost. Full article

The increasing use of herbicides in intelligent agricultural production is driven by the time-consuming nature of manual weeding, as well as its ephemeral effectiveness. However, herbicides like butachlor degrade slowly and can be washed away by rainwater, ultimately flowing into the farm ponds and posing risks to aquatic plants. To identify and recommend superior restoration strategies that effectively address the challenges posed by butachlor, we investigated the impacts of butachlor on the growth and physiology of four common aquatic plants (i.e., Hydrilla verticillata, Ceratophyllum demersum, Potamogeton maackianus, and Myriophyllum aquaticum) and their potential role in mitigating environmental damage by reducing residual herbicide levels. Our findings indicated that M. aquaticum was tolerant to butachlor, exhibiting higher growth rates than other species when exposed to various butachlor concentrations. However, the concentration of butachlor negatively impacted the growth of H. verticillata, C. demersum, and P. maackianus, with higher concentrations leading to more significant inhibitory effects. After a 15-day experimental period, aquatic plants reduced the butachlor residuals in culture mediums across concentrations of 0.5 mg/L, 1 mg/L, and 2 mg/L compared to non-plant controls. Our findings classified P. maackianus as butachlor-sensitive and M. aquaticum as butachlor-tolerant species. This investigation represents novel research aimed at elucidating the contrasting effects of different concentrations of butachlor on four common aquatic species in the agricultural multi-pond system. Full article

Mushroom cultivation produces a significant amount of wastewater containing high levels of both organic and inorganic contaminants. In this study, mushroom farm wastewater (MFW) was treated separately by aquatic macrophytes (Ceratophyllum demersum L.) and algae (Chlorella vulgaris). The laboratory experiments consisted of a constructed reactor planted with selected aquatic plants and a microalgal culture and operated for 16 days. The pollutant removal efficiency was evaluated using different experimental combinations such as control 1 (C. demersum using borewell water), control 2 (C. vulgaris using borewell water), T1 (C. demersum using MFW), and T2 (C. vulgaris using MFW), respectively. The results showed that the T1 treatment had the highest significant (p < 0.05) removal efficiency of selected pollutant parameters (total dissolved solids: 86.00%; biochemical oxygen demand: 83.10%; chemical oxygen demand: 86.60%; total nitrogen: 84.30%; total phosphorus: 75.60%). The kinetic studies using the first-order reaction model showed a good fit (R² > 0.8317) and the maximum rate constant (k) of pollutant reduction in T1 treatment. In addition, the growth, biochemical, and proximate parameters of both C. demersum and C. vulgaris were highest in the same treatment. Therefore, the proposed experiment offers a promising approach for the efficient and environmentally friendly treatment of MFW. Full article

Submerged macrophyes have been widely used to restore aquaculture ponds in recent years. Yet, whether the residual antibiotics in ponds will affect the remediation effect of submerged macrophyes, and the effect of different submerged macrophyes on the water and sediment in aquaculture ponds with antibiotic residues, is unclear. A microcosm experiment was carried out to study the interaction between three kinds of submerged macrophytes and their growing environment with antibiotic residues. Ceratophyllum demersum L. with no roots, Vallisneria spiralis L. with flourish roots, and Hydrilla verticillata L with little roots were chosen to be planted in the sediment added with enrofloxacin (ENR). The growth of submerged macrophytes, the changes of the overlying water and sediment characteristics, and the microbial community in the sediment were analyzed. The results showed that according to the growth rate and nutrients accumulation ability, V. spiralis with flourish roots performed best among the three submerged macrophytes. The concentrations of TOC, TP, NH₄⁺-N, and TN in the overlying water were 25.0%, 71.7%, 38.1%, and 24.8% lower in the V. spiralis treatment comparing with the control, respectively. The richness and diversity of the microorganisms in the sediment of V. spiralis treatment were significantly higher than those in the control, but this advantage was not obvious in the H. verticillata treatment. V. spiralis promoted the growth of Proteobacteria (22.8%) and inhibited the growth of Acidobacteria (32.1%) and Chloflexi (31.7%) in the rhizosphere sediment with ENR residue. The effects of the three submerged macrophytes on the removal of ENR from sediment were not reflected due to the limitation of water depth. Compared with C. demersum and H. verticillata, V. spiralis was more suitable for the remediation of the aquaculture ponds with ENR residue. Full article

Ceratophyllum L. is a cosmopolitan genus of perennial aquatic herbs that occur in quiet freshwaters. Fossils of this genus have been widely reported from the Northern Hemisphere, most of them occurring in the temperate zone. Here, we describe two species of fossil fruits discovered from subtropical areas of China. The fossil fruit discovered from the upper Eocene Huangniuling Formation of the Maoming Basin is designated as C. cf. muricatum Chamisso, and fruits discovered from the Miocene Erzitang Formation of the Guiping Basin are assigned to the extant species C. demersum L. The discovery of these two fossil species indicates that Ceratophyllum had spread to South China by the late Eocene and their distribution expanded in subtropical China during the Miocene. Full article

The contribution discusses macrophyte communities in natural and man-made waterbodies located on the active floodplain along the Drava river (Slovenia). We presumed that these different types of wetlands host a great number of macrophyte species, but this diversity may be affected by the presence of alien invasive species Elodea canadensis and E. nuttallii. Presence, relative abundance, and growth forms of plant species along with selected environmental parameters were monitored. Correlation analyses and direct gradient analyses were performed to reveal the possible relations between the structure of macrophyte community and environmental parameters. Number of macrophytes in surveyed water bodies varied from 1 to 23. Besides numerous native species we also recorded Elodea canadensis and E. nuttallii, which were present in 19 out of 32 sample sites, with E. nuttallii prevailing. The less invasive E. canadensis was absent from ponds and oxbow lakes but relatively abundant in side-channels, while E. nuttallii was present in all types but dominant in ponds. The most abundant native species were Myriophyllum spicatum and M. verticillatum, Ceratophyllum demersum and Potamogeton natans. Correlation analyses showed no negative effect of the invasive alien Elodea species to the species richness and diversity of native flora. Positive correlation between the abundance of E. nuttallii and temperature of the water was obtained. Full article

The use of parabens in personal care products can result in their leakage into water bodies, especially in public swimming pools with insufficient water treatment. We found that ferrite-based nanomaterials could catalytically enhance ozone efficiency through the production of reactive oxygen species. Our objective was to develop a catalytic ozonation system using ternary nanocomposites that could minimize the ozone supply while ensuring the treated water was acceptable for disposal into the environment. A ternary CuFe₂O₄/CuO/Fe₂O₃ nanocomposite (CF) delivered excellent degradation performance in catalytic ozonation systems for butylparaben (BP). By calcining with melamine, we obtained the CF/g-C₃N₄ (CFM) nanocomposite, which had excellent magnetic separation properties with slightly lower degradation efficiency than CF, due to possible self-agglomeration that reduced its electron capture ability. The presence of other constituent ions in synthetic wastewater and actual discharge water resulted in varying degradation rates due to the formation of secondary active radicals. ¹O₂ and ^•O₂⁻ were the main dominant reactive species for BP degradation, which originated from the O₃ adsorption that occurs on the CF≡Cu^(I)–OH and CF≡Fe^(III)–OH surface, and from the reaction with ^•OH from indirect ozonation. Up to 50% of O₃-treated water resulted in >80% ELT3 cell viability, the presence of well-adhered cells, and no effect on the young tip of Ceratophyllum demersum L. Overall, our results demonstrated that both materials could be potential catalysts for ozonation because of their excellent degrading performance and, consequently, their non-toxic by-products. Full article

Growth-regulating factors (GRFs) are plant-specific transcription factors that play essential roles in regulating plant growth and stress response. The GRF gene families have been described in several terrestrial plants, but a comprehensive analysis of these genes in diverse aquatic species has not been reported yet. In this study, we identified 130 GRF genes in 13 aquatic plants, including floating plants (Azolla filiculoides, Wolffia australiana, Lemna minuta, Spirodela intermedia, and Spirodela polyrhiza), floating-leaved plants (Nymphaea colorata and Euryale ferox), submersed plants (Zostera marina, Ceratophyllum demersum, Aldrovanda vesiculosa, and Utricularia gibba), an emergent plant (Nelumbo nucifera), and an amphibious plant (Cladopus chinensis). The gene structures, motifs, and cis-acting regulatory elements of these genes were analyzed. Phylogenetic analysis divided these GRFs into five clusters, and ABRE cis-elements were highly enriched in the promoter region of the GRFs in floating plants. We found that abscisic acid (ABA) is efficient at inducing the turion of Spirodela polyrhiza (giant duckweed), accompanied by the fluctuated expression of SpGRF genes in their fronds. Our results provide information about the GRF gene family in aquatic species and lay the foundation for future studies on the functions of these genes. Full article

We aimed to determine the effects of water level and habitat heterogeneity on gastropod fauna in the littoral zone, and the differentiation of functional feeding guilds (FFG) of gastropods. Two periods were analyzed: 2012 (low water level, LWL) and 2013 (high water level, HWL) in the littoral zone of two shallow waterbodies (Sutla backwater, NW Croatia). Waterbody S1, covered with Ceratophyllum demersum, was sampled in the macrophyte stands, and the littoral benthal area, while waterbody S2, without macrophytes, was sampled only in the littoral benthal area. It was observed discovered that among the macrophyte stands in S1, gastropods were significantly more abundant during LWL. The same trend was observed in the littoral benthal area of S2. In contrast, gastropod abundance was higher in the littoral benthal area of S1 during HWL. Comparing gastropods in the two waterbodies, the abundance in S1 was ten times higher than in S2. The most abundant species was Gyraulus parvus, which accounted for 51–92% of the gastropods observed among the macrophytes of S1 and 86% in the adjacent benthic zone. Among the FFG groups, grazers (particularly those feeding on gymnamoebae and rotifers) had the largest proportion, followed by shredders feeding on small pieces of macrophytes. In our research, we indicate the important role of microhabitat diversity and submerged macrophytes as a rich food source for gastropods and safe shelter from predators. Full article