Project description:In many aquatic plant taxa, classification based on morphology has always been difficult. Molecular markers revealed that the complexity in several of these aquatic taxa could be addressed to recurrent hybridization events and cryptic species diversity. The submerged macrophyte genus Ruppia is one of these aquatic genera with a complex taxonomy due to the absence of clear distinguishable traits and several hybridization events. Two species co-exist throughout Europe, R. maritima and R. spiralis (previously known as R. cirrhosa), but recent molecular studies also found several indications of hybridization, introgression and chloroplast capture between these species. However, the full extent and frequency of hybridization and introgression in this genus has not been studied so far, nor is it clear how these hybrid lineages can co-exist locally with their parental species. In this paper, we wanted to detect whether a single coastal wetland where both species co-exist can act as a Ruppia hybrid zone. As a case study, we chose the Camargue, a Mediterranean coastal wetland that harbors a wide diversity in aquatic habitats, especially in terms of salinity and hydro-regime. We sampled several Ruppia populations within this wetland. To identify each sample and reconstruct the local genetic structure of the two parental species and their hybrids, we used both chloroplast and nuclear microsatellite markers. Afterward, we tested whether different species had different habitat preferences. Our results confirmed that R. maritima and R. spiralis are two strongly divergent species with different reproductive ecologies and different habitat preferences. This prevents frequent hybridization and consequently we could not detect any trace of a recent hybridization event. However, we found several populations of later-generation hybrids, including a population of R. maritima x hybrid backcrosses. The hybrid populations occupy a different habitat and are genetically distinct from their parental species, although they tend to be morphological similar to parental R. maritima. Although local hybridization and introgression in Ruppia is less frequent than we expected, the taxonomy of Ruppia is complicated due to ancient hybridizations and several back-crossings.
Project description:The taxonomy of Ruppia has long been confused due to its high plasticity in morphology. In this study, the complete plastid genome sequence of Ruppia brevipedunculata was successfully sequenced by the technology of Illumina. The whole plastid genome length was 158,943 bp and contained a typical quadripartite structure including one large single copy (LSC) region (88,857 bp), one small single copy (SSC) region (19,130bp) and a pair of inverted repeats (IR) regions (25,478bp). The GC content of this genome was 35.8%. The whole genome contained 132 genes including 87 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogenetic analysis indicated that R. brevipedunculata and R. sinensis formed a distinct clade separated from Potamogeton perfoliatus.
Project description:Saline municipal wastewater treatment is a challenging environmental issue in coastal cities, due to the discharge of saline water into the sewers. The present research article focuses on the phytoremediation of high saline municipal wastewater by Ruppia maritime, a widespread plant which can be found in saline medium such as traditional fish ponds, estuaries, tidal flats, salt pans, coastal paddy fields, coastal lagoons, marsh pools, and mangrove salt marshes in Khuzestan province, Iran. The experimental data was obtained using a pilot plant constructed in Chobeineh wastewater treatment plant in Ahvaz city, fed by activated sludge effluent in 3 levels of electrical conductivity (EC) (10, 15, 20 ms cm-1), during 45 days of the experiment. Chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP) and total suspended solids (TSS) were daily monitored in blank and pilot study. The COD removal decreased from 83.26% to 72.39% by increasing the EC level from 10 to 20 ms cm-1, respectively. The experimental data will practically be an appropriate source of information for environmental engineers to design a natural treatment scenario for saline wastewater treatment.
Project description:Oil spills threaten the productivity of ecosystems through the degradation of coastal flora and the ecosystem services these plants provide. While lab and field investigations have quantified the response of numerous species of emergent vegetation to oil, the effects on submerged vegetation remain uncertain. Here, we discuss the implications of oil exposure for Ruppia maritima, one of the most common species of submerged vegetation found in the region affected by the recent Deepwater Horizon oil spill. We grew R. maritima in a range of manipulated sediment oil concentrations: 0, 0.26, 0.53, and 1.05 mL oil /L tank volume, and tracked changes in growth (wet weight and shoot density/length), reproductive activity (inflorescence and seed production), root characteristics (mass, length, diameter, and area), and uprooting force of plants. While no statistical differences were detected in growth, plants exhibited significant changes to reproductive output, root morphology, and uprooting force. We found significant reductions in inflorescences and fruiting bodies at higher oil concentrations. In addition, the roots growing in the high oil were shorter and wider. Plants in medium and high oil required less force to uproot. A second experiment was performed to separate the effects of root morphology and oiled sediment properties and indicated that there were also changes to sediment cohesion that contributed to a reduction in uprooting forces in medium and high oil. Given the importance of sexual reproduction for these plants, oil contamination may have substantial population-level effects. Moreover, areas containing buried oil may be more susceptible to high energy storm events due to the reduction in uprooting force of foundation species such as R. maritima.
Project description:Ruppia is widely distributed in marine and inland saline habitats in temperate and tropical regions. In this study, the complete chloroplast genome sequence of R. sinensis was successfully obtained using Illumina sequencing. The full length of the chloroplast genome length was 158,897 bp with a typical quadripartite structure: one large single copy (LSC) region (88,952 bp), one small single copy (SSC) region (19,047 bp), and a pair of inverted repeats (IR) (25,449 bp each). The GC content of this genome was 35.9%. The whole genome contained 136 genes, including 88 protein-coding genes, 40 tRNA genes, and eight rRNA genes. Phylogenetic analysis indicated that R. sinensis formed a distinct clade, being separated from Zostera marina and Potamogeton perfoliatus.