Chara Fibrosa Research Articles

On the Morphology of Five Species of <I>Chara</I> (Characeae, Charophyta) from West Bengal, India

Five representatives belonging to the family Characeae have been studied under the genus Chara L. viz., Chara fibrosa C. Agardh ex Bruzelius, Chara socotrensis Nordst., Chara zeylanica Klein ex Willd., Chara vulgaris L. and Chara hydropithys Rchb. occurring in West Bengal. The studies have been done under stereo zoom and Field emission Scanning Electron Microscope (FeSEM). FeSEM observations for the morphology of oospores are the first time in Eastern India. The occurrence of Chara socotrensisis Nordst. reported for the first time from Eastern India.

The Contribution of Historical and Morphological Studies on Herbarium Specimens to a Better Definition of Chara pelosiana Avetta (Charales, Charophyceae).

The lectotype of Chara pelosiana Avetta 1898 was designated in 2000 by Langangen, who merged the species with Chara fibrosa Agardh ex Bruzelius. Chara pelosiana belongs to the section Agardhia Wood, but the true identity of the species has yet to be confirmed. The purpose of this work is to show some historical and morphological findings regarding this enigmatic species, on the basis of the analysis of herbarium specimens. The original material, which was studied by Avetta, is missing in Italian herbaria, but portions of it have been found in the Herbarium of Jena. Historical research on botanists related with this species resulted in the discovery of several specimens to be considered “original material”, and new unpublished localities in Northern Italy. Morphological observations have been made on portions of herbarium specimens as a contribution to unveil the taxonomic identity of this taxon. The specimens are diplostichous with ecorticate branchlets, have stipulodes in a single row, one or two per branchlet, and spine cell up to 1 mm long.

A contribution to the knowledge of charophytes in Myanmar; morphological and genetic identification and ecology notes

ABSTRACT Information on the distribution and species composition of charophytes in Myanmar is scarce. Only a few studies on charophytes in ponds were conducted in Myanmar at the end of the nineteenth and first half of the twentieth century and lake habitats were not included in these studies. To increase the knowledge, we investigated Chara spp. from seven Myanmar lakes and reservoirs. In a polyphasic approach using morphological traits and DNA barcoding the specimens found were classified as Chara zeylanica and Chara fibrosa. Chara zeylanica is the most common of the two species found in Myanmar and was observed in five lakes, while Chara fibrosa was only found in three lakes. Chara zeylanica seems to prefer calcareous lakes while C. fibrosa was found in both highly and moderate alkaline lakes. Both species were recorded in low-impacted lakes only, with total phosphorous (TP) concentrations below 20 µg L−1. Increased human impact on freshwater habitats must therefore be considered as a factor reducing Chara biodiversity in Myanmar.

Report on Charophytes from rice fields in northern Italy including the alien species Chara fibrosa ssp. benthamii

The paper describes the discovery in rice fields of northern Italy of three species of Charophytes rarely reported in Italy, Chara fibrosa ssp. benthamii, a tropical taxon not native to the European Charophyte Flora, previously recorded in Italy only once, in the nineteenth century, Nitella translucens and N. mucronata.

Reconstruction of the charophyte community of Lake Shinji by oospore collection

Submerged aquatic vegetation (SAV) aids in maintaining a clear stable state in shallow lakes. However, charophytes are more effective in increasing transparency compared to angiosperms. Lake Shinji was more transparent prior to the beginning of herbicide use for rice weed control in the mid-1950s, because its bottom was covered by SAV up to 3 m depth. Although Chara braunii C.C. Gmelin and Nitella hyaline (De Candolle) C. Agardh were recorded in the 1960s, there are no reports on SAV in the 1950s. Therefore, in the present study, we aimed to show that the SAV of Lake Shinji was mostly composed of charophytes prior to the 1950s, by conducting a seed analysis. We obtained charophyte oospores from the sediment, but seeds of angiosperms were not identified. In addition to C. braunii that was previously recorded in Lake Shinji, we also found two newly identified species, Chara corallina Willdenow and Chara fibrosa C. Agardh ex Bruzelius. Overall, this study indicates that seed analysis is helpful in reconstructing the former flora of Lake Shinji.

Dynamic aspects of spermiogenic chromatin condensation patterning by phase separation during the histone-to-protamine transition in charalean algae and relation to bryophytes

During early-to-middle spermiogenesis in multicellular, internally fertilizing charalean green algae (Chara fibrosa, Chara vulgaris, Chara tomentosa, Nitella missouriensis), patterning of chromatin/nucleoplasm in developing spermatid nuclei changes from granules → fibers → contorted lamellae → condensed chromatin. Cytochemical, immunocytochemical, electrophoretic studies on C. vulgaris and C. tomentosa spermatids (Kwiatkowska, Poplonska) and amino acid analysis of protamines in Chara corallina sperm (Reynolds, Wolfe), indicate that more positively charged protamines replace histones directly during spermiogenesis, not indirectly through other intermediate transitional proteins as in internally fertilizing neogastropods and sharks with more ordered spermatid lamellae. We hypothesize that such lamellar-mediated patterning is due to liquid-liquid phase separation by spinodal decomposition. This is a spontaneous thermodynamic process that involves diffusive instability of a lamellar chromatin network, a dominant pattern repeat distance and bicontinuity of chromatin/nucleoplasm phases. C. vulgaris sperm show contorted lamellae in the posterior region, whereas C. corallina sperm display contorted peripheral lamellae and interior fibrils. Among internally fertilizing liverworts, which may have evolved from Zygnematales, mid-spermatid nuclei lack lamellae. Instead they display self-coiled chromatin rods in Blasia pusilla, contain short chromatin tubules in Haplomitrium hookeri resembling those in internally fertilizing mosses and a hornwort and indirectly replace histones with protamines in Marchantia polymorpha.

Effect of calcium and magnesium on the growth and calcite encrustation of Chara fibrosa

Chara fibrosa was grown hydroponically using three treatment concentrations (4, 40, and 80ppm) of calcium (Ca), magnesium (Mg), and their combination (Ca+Mg) for 6 weeks in order to determine the effect of Ca and Mg on its growth and calcite encrustation. Calcite encrustation was positively correlated with the concentration of Ca in the water; however, when plants were grown in water containing high concentrations of Ca, shoot elongation was retarded and chlorophyll content was relatively low. The presence of Mg in the water inhibited calcite encrustation in C. fibrosa and magnesite was not deposited on plants, even in those plants that received Mg without Ca. Further, a high concentration of Ca in the water significantly decreased the Fv/Fm value of C. fibrosa. The presence of Mg in the media slightly decreased the stress caused by the excessive presence of Ca. Encrustations were observed in the intercellular space of plants, and point analysis performed using electron microscopy indicated that these encrustations were composed of calcite. Line analysis and element mapping confirmed that the encrustations contained only Ca with most of the Mg distributed in the cells of C. fibrosa.

Evidence of Chara fibrosa Agardh ex Bruzelius, an alien species in South France

The paper describes the discovery of a species of genus Chara, hitherto unknown in France. The morphological features of the plants and oospores are shown and identify the plant as Chara fibrosa ssp. benthamii, a tropical taxon, non-native to the European Charophyte flora. The ecological conditions of this particular find correspond to an artificial temporary pond located in the Crau plain, north of the Camargue. In contrast to the normal hydrological cycle ruled by local precipitation during winter, the studied pond is flooded from irrigation water in late spring and during summer. This context allowed C. fibrosa to out-compete the indigenous Chara species, Chara vulgaris and Chara globularis. The accidental introduction of C. fibrosa is attributed to original contamination from rice seed material imported to the nearby Camargue, rather than to dispersal by migratory water birds. Although the species has formed a very large population in that pond within a few years, it might not be classified as “invasive” because this occurrence is linked to a particular man-made habitat. However, spread of the species in the future, as a function of global warming related to climate change, cannot be excluded.

Review of the species concepts Chara fibrosa and C. flaccida (Characeae, Charophyceae)

Taxonomic circumscriptions of the charophyte taxa Chara fibrosa C.Agardh ex Bruzelius. and C. flaccida var. wightii A.Braun are revised, and both taxa are recognised at species rank, as C. fibrosa and C. wightii (A.Braun) Casanova. Both species are illustrated and a review of relevant morphological characters is also presented.

Spatial structuring of submerged aquatic vegetation in an estuarine habitat of the Gulf of Mexico

Seasonal changes in spatial structure of biomass of submerged aquatic vegetation (SAV) and environmental variables were evaluated in Celestun Lagoon, an estuarine habitat in Mexico. Geostatistical techniques were used to evaluate spatial autocorrelation and to predict the spatial distribution by kriging. The relative contribution of 11 environmental variables in explaining the spatial structure of biomass of SAV was evaluated by canonical correspondence analysis. Spatial partitioning between species of SAV was evident: the seagrasses Halodule wrightii and Ruppia maritima dominated the seaward and central zones of the lagoon, respectively, whereas the green alga Chara fibrosa was constrained to the inner zone. The spatial structure and seasonal variability of SAV biomass were best explained by organic carbon in the sediments, salinity and total suspended solids in the water column. Analysis at different spatial scales allowed identifying the importance of spatial structure in biotic and abiotic variables of this estuarine habitat.

The effect of flow turbulence on growth, nutrient uptake and stable carbon and nitrogen isotope signatures inChara fibrosa

Exposure to water movement has been observed to alter various processes in the plants including growth, hormone concentration and nutrient uptake. In the current study, Chara fibrosa was exposed to three different turbulence conditions and compared with a control. Turbulence was generated in the laboratory by using a vertically oscillating grid setup. Exposure to turbulence caused a reduction in shoot length and nutrient uptake in C. fibrosa. Variation of stable isotope composition was measured as a surrogate variable that is able to integrate variations of many physiological processes. It was initially hypothesized that the reduction of diffu- sion boundary layer around the plant will increase isotopic discrimination against 13 C and 15 N, when exposed to increasing turbulence. Although the results generally agree with the hypothesis, a trend of increment was observed in d 13 C in the plants exposed to turbulent velocities from 0.46 to 1.93 cm s x1 , against the hypothesis. Mechanical stress induced reduction of carbon uptake and lipid peroxidation due to the development of oxidative stress may be the reasons behind the above-mentioned trend. The study exhibits that the net effect of physical and physiochemical changes of the plants was displayed in d 13 C signatures and it is important to consider physical conditions of the local environment, in using stable isotope signatures for ecosystem studies.

Influence of flow turbulence on Chara fibrosa: growth, stress, and tissue carbon content

The influence of flow turbulence on the growth of Chara fibrosa was studied for 12 weeks under laboratory conditions using a mechanically oscillating grid that generated turbulence without net flow. The experimental turbulence velocities were 1.93 ± 0.48 cm s−1 (high turbulence), 1.06 ± 0.41 cm s−1 (medium turbulence), and 0.46 ± 0.15 cm s−1 (low turbulence), while the control was a no turbulence condition. Plants exposed to high and medium turbulence showed shoot elongation rates less than 50% of the control throughout the experiment period. Ascorbate peroxidase activity and catalase activity were elevated, and reductions of total chlorophyll content and photosynthetic efficiency were observed in the plants exposed to turbulence. Carbon content of the plant tissue was decreased in the high and medium turbulence treatments; in contrast, it was slightly increased in the treatment of low turbulence. Exposure to turbulence adversely affected growth of C. fibrosa, though all the plants survived the experiment period.

Development and application of optical sum frequency microscopy

AbstractWe have developed a microscope for the acquisition of optical sum frequency (SF) intensity images and have observed two types of samples. We have observed resonant electronic and vibrational images of the H‐Si(111) surface in UHV conditions after IR light irradiation of pulse width ∼6 µs. In the resonant SF intensity images, we identified the images of areas covered by SiH species. Nonresonant SF signals appeared in the area irradiated by the IR light pulses, originating from a nonlinear optical transition involving the surface electronic levels in the Si dangling bonds. We also found an unidentified bonding state on the edges of the irradiated area in some light conditions. We have also observed images of a water plant Chara fibrosa by this SF microscope in air. We found that the starch is observed selectively in the oogonium of the water plant and the amylopectin was found to be one of the main ingredients in it. Copyright © 2010 John Wiley & Sons, Ltd.

Levantamento florístico das Characeae (Chlorophyta) de Mato Grosso e Mato Grosso do Sul, Brasil: Chara

O levantamento florístico do gênero Chara (Characeae, Chlorophyta) nos Estados de Mato Grosso (18°55'05"S, 54°50'39"W) e Mato Grosso do Sul (19°12'03"S, 57°35'32"W), Brasil, resultou na identificação, descrição e ilustração das seis espécies seguintes: Chara fibrosa C. Agardh ex Bruzelius emend. R. D Wood var. hydropitys (Reichenbach) R. D. Wood emend. R. D. Wood f. hydropitys, C. guairensis R. Bicudo, C. kenoyeri Howe, C. martiana Wallman, C. rusbyana Howe e C. socotrensis Nordstedt in Kuhn emend. R. D. Wood. Foram analisadas 93 amostras coletadas em 15 municípios e o material provém de coleções dos herbários CPAP, HMS e SP. A presença de Chara fibrosa var. hydropitys f. hydropitys e de C. guairensis, C. kenoyeri e C. socotrensis é documentada pioneiramente para os Estados de Mato Grosso e Mato Grosso do Sul, respectivamente. A citação de C. martiana é pioneira para ambos os Estados. Chara guairensis foi a espécie que apresentou a mais ampla distribuição geográfica na área estudada, havendo sido coletada em nove localidades distintas, enquanto que C. kenoyeri e C. socotrensis foram as que apresentaram a distribuição geográfica mais restrita, ocorrendo em apenas duas localidades cada uma.

Calcite encrustation in macro-algae Chara and its implication to the formation of carbonate-bound cadmium

We studied the relationship between macro-algae Chara (Stoneworts) calcite (CaCO 3) encrustation and the speciation of cadmium (Cd) accumulated by the plant. Results showed that 17% of the total Cd (0.3 mg kg −1) accumulated by Chara fibrosa exposed to 1 μg Cd L −1 was carbonate-bound. The percentage of carbonate-bound Cd in the plant exposed to 10 μg Cd L −1 increased from 48% in young thalli (total Ca < 50 mg g −1, total Cd: 125 mg kg −1) to 63% in calcified mature thalli (total Ca: 190 mg g −1; total Cd: 134 mg kg −1). Based on mineral saturation calculation and reliability analysis of the sequential fractionation procedure, precipitation of otavite (CdCO 3) and co-precipitation of Cd with calcite, occurring in the alkaline regions of Chara cell wall, are probably the mechanisms of carbonate-bound Cd formation. Thick marl sediment frequently found beneath charophyte meadows suggests a long-term storage of Ca as well as the precipitated or co-precipitated Cd in the sediment after the plant senescence and decomposition.

Biomass dynamics of charophyte-dominated submerged macrophyte communities in Myall Lake, NSW, Australia

The dynamics of submerged macrophytes were studied in a large and shallow near-pristine lake in New South Wales, Australia. The objectives were to investigate the seasonal dynamics in biomass of Chara fibrosa, Nitella hyalina and Najas marina both in time and space, and to characterise the underlying relationship between the plant biomass and both the gyttja and water depths. Charophytes were most densely grown in the north-east bays of the lake compared to the north-west bays. Average biomass of Chara fibrosa was highest at the north-east bays of this lake (e.g. 210 g d.w m−2) followed by north-west bays (e.g. 148 g d.w/m2), South-west bays (e.g. 60 g d.w/m2) and lastly central deep area of the lake (e.g. 31 g d./m2). A similar trend was displayed by Nitella hyalina biomass where at the north-east bays the biomass was the highest (e.g. 167 g d.w m−2) followed by north-west bays (e.g. 128 g d.w/m2), south-west bays (e.g. 38 g d.w/m2) and central deep area of the lake (e.g. 23 g d.w/m2). During the summer season the maximum total biomass of charophytes at Corrigans bay was recorded (e.g. 300 g d.w/m2), mostly being dominated by Nitella hyalina. Total biomass of charophyte was reduced during the winter season (e.g. 50 g d.w m−2). Najas marina biomass remained low both in time and space except in May at Bibby harbour and Shelly beach where its biomass peaked (e.g. 276 and 175 g d.w m−2 respectively). Gyttja depth showed a positive relationship with total charophyte biomass (r2 = 0.70; p<0.01) and it seemed to favour the growth of charophytes at the expense of other submerged macrophytes, e.g. Myriophyllum sp. and Vallisneria sp. Water depth displayed a negative relationship with total charophyte biomass (r2=−0.94; p<0.01). Both Chara fibrosa and Nitella hyalina correlated positively with gyttja depth (r, r; p<0.01) and negatively with water depth (r, r; p<0.01). Najas marina correlated positively only with water depth (r2=0.67, p<0.01).

Mechanisms affecting biomass and distribution of charophytes and Najas marina in Myall Lake, New South Wales, Australia

Two years of measurements are explored with a view to formulating an ecosystem model for Myall Lake. Stable physical characteristics, low catchment loads, low light attenuation, flat-bottomed hypsometry, and soft gyttja substrate allow stable charophyte biomass throughout the year in Myall Lake. Chara fibrosa dominates the total biomass and is abundant over the depth range 0.5–4 m. Nitella hyalina is found over the same depth range but has diminished biomass at depths greater than 2 m due to increased incidence of zero-biomass samples at depths greater than 1.5 m. Upper bounds for biomass densities were estimated for charophytes. Najas marina has great seasonal variability and meadows can have very high biomass in waters 1.5–2.7 m deep. High biomass of Najas marina is associated with low biomass of Nitella hyalina and may be a factor determining how the biomass of Nitella hyalina is distributed with respect to depth. Patchiness of Najas marina is particularly high. Temperature and light can support two growing seasons for Najas marina but mechanical disturbance is often high in spring and high biomass was only observed in late autumn during the present study. Less than 5% of the present-day production of submerged macrophytes would have been required to produce organic material of the gyttja over a 1,000-year period. The spatial distributions of gyttja and the dominant macrophytes are consistent with wind patterns. Down-lake limits on the distributions of charophytes and Najas marina are related to a gradient in the coefficient of light attenuation that is, in turn, related to proximity to the bulk of the catchment load.

Morphological and reproductive acclimations to growth of two charophyte species in shallow and deep water

We investigated the distribution of two charophyte species, Chara fibrosa var. fibrosa (A. Br.) and Nitella hyalina (DC.) Ag., in Myall Lake, a shallow lake in New South Wales, Australia, in an attempt to elucidate the factors causing their distribution patterns. The field study was carried out from July 2003 to May 2005 and charophytes were sampled together with bottom sediments at 20 sampling locations in the lake on 13 occasions. Charophyte biomass (0–321 g DW m −2) displayed an optimum curve with depth and maximum biomass occurred between 1 and 2.5 m depth. In deeper water, shoots were longer (i.e., around 30 cm at 1 m depth to 60–90 cm between 2 and 4 m depth). Oospore and antheridia densities were higher in shallower water with a maximum around 80 cm. Plants growing in shallow depths had shorter internodes implying a short life cycle of shoots, and nodal spacing was relatively regular in contrast to its deep water counterparts although spacing tended to increase at locations farther from the apex. The present study also reports that there is an apparent decline in sexual propagule production rates with increasing water depth, further highlighting the different morphological and reproductive acclimations of charophytes in shallow and deep water.

Difference characteristics of phosphorus in Chara and two submerged angiosperm species: implications for phosphorus nutrient cycling in an aquatic ecosystem

Phosphorus speciation in three submerged macrophytes species, Chara fibrosa Agardh ex Bruzelius, Najas marina Linnaeus and Vallisneria gigantea Graebner, and the implications for phosphorus nutrient cycling in an aquatic ecosystem were studied, using sequential phosphorus fractionations. The results showed that C.␣fibrosa had a far higher residual ash and calcium content compared with the two angiosperm species, but lower total phosphorus content. Two different fractionation methods for phosphorus showed that the bioavailable water-soluble phosphorus (H2O-P) and ammonium chloride extractable phosphorus (NH4Cl-P) of the extractions used represented the major part of total plant phosphorus in the two angiosperm species, while organic phosphorus (NaOH-P) represented a relatively large fraction in C. fibrosa. In this species, about 12–15% of total plant phosphorus was calcium-bound phosphorus (HCl-P), occurring as co-precipitation with calcite encrustation, but this fraction was negligible in the two angiosperm species, i.e. less than 1%. The redox-insensitive forms of HCl-P are considered less bioavailable and not affected by anoxic conditions of bottom sediment, thus have potential as a phosphorus nutrient sink in aquatic ecosystems.

Does Calcite Encrustation in Chara Provide a Phosphorus Nutrient Sink?

We studied the effect of calcite encrustation in stoneworts (Chara spp.) on P cycling in an aquatic ecosystem. Sequential fractionation was performed to quantify P fractions of the internodes of calcified (Ca-CF) and uncalcified (UCa-CF) Chara fibrosa Agardh ex Bruzelius. Our results showed that Ca-CF was able to store more P and about 14 to 23% of total P in Ca-CF was co-precipitated with encrusted calcite, while only 2 to 3% was found in UCa-CF. Furthermore, in Ca-CF, an increased amount of total P did not result in a higher release of bioavailable water-soluble and sodium hydroxide-extractable P. Extracellular calcification in Chara enhanced nutrient sink for P, provided a further bottom-up control of phytoplankton, and should be regarded as a positive feedback in stabilizing Chara dominance in lakes.