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The development of nanotechnologies represents a promising way to improve sustainable agriculture because nanoparticles can be used as fertilizers, fungicides, herbicides, insecticides, can reduce the stress caused by various factors (salinity) or can be used for seed priming. Green synthesis is an important method to produce nanoparticles due to the lack of toxic waste and because is relatively simple and cheap. However, nanoparticles have unique properties that influence their bioavailability, bioaccumulation and toxicity. Because of this ecotoxicological research, which studies the effect of nanoparticles on plants are important. In this study, we determined the effect of spore extracts with green synthesized bimetallic nanoparticles on cucumber. For obtaining the extracts, we used spores from two species of ferns (Asplenium scolopendrium and Dryopteris filix-mas) and two types of solvents (water and hydroalcoholic solution). The bimetallic nanoparticles (Au:Ag 1:1 and Au:Ag 1:10) were synthesized using HAuCl4 and AgNO3. The extracts were tested in Cucumis sativus seeds after being diluted 10 and 100 times, respectively. Exposure of Cucumis sativus seeds to aqueous extracts of A. scolopendrium and D. filixmas spores with and without bimetallic nanoparticles has usually stimulated root growth, while the stem growth was stimulated only at the variants without bimetallic nanoparticles. For the hydroalcoholic extracts, at the variants with extracts with bimetallic nanoparticles diluted 100 times were obtained better results than in control with water or with hydroalcoholic solutions. [ABSTRACT FROM AUTHOR]

Invasive plants are one of the biggest threats to biodiversity. The invasive plant species have a high allelopathic potential, which helps them spread to new areas. The allelopathic effect of invasive species on different plants varies upon to the phenophase. Erigeron annuus is an annual invasive alien species, which we can find in Romania. This paper investigated the allelopathic effect induced by aqueous and hydroalcoholic extracts obtained from Erigeron annuus (L.) Desf. subsp. annuus on crop species. The extracts were obtained using dried plant material from the aerial parts of the plant: stems, leaves, inflorescences. For each type of extract, we used two dilutions: 1:10 and 1:100. We used the seed of three of the most important crop plants: wheat (Triticum aestivum L.), cucumber (Cucumis sativus L.) and pea (Pisum sativum L.). After hydration, the seeds were immersed for one hour in extracts, and then put in Petri dishes in the dark. The parameters which were determined after four days of the beginning of the experiment are the length of the root and stem, fresh and dry biomass. The influence of extracts was more pronounced at the roots than at the stems of the seedlings, regardless of species. The effect varies upon the type of extract and upon the species. The hydroalcoholic extract diluted 10 times inhibited growth, especially in the case of dicotyledons. [ABSTRACT FROM AUTHOR]

The paper aims to determine the lead-induced physiological, biochemical and enzymatic changes in Asplenium scolopendrium, which could represent biomarkers used in environmental assessment. Of all the physiological processes, photosynthesis and respiration were analyzed and the enzymatic and biochemical determinations focused on catalase activity, assimilatory pigment concentration, polyphenol content and lead presence in tissues.The stress induced by the exposure to Pb of the species Asplenium scolopendrium determined an increase in the carotenoid content, the catalase activity, the total polyphenol content and also enhanced the respiration potential. No significant changes were recorded regarding the chlorophyll content and the photosynthetic activity. The recorded changes may be used as non-specific markers in the assessment of the impact of Pb on plants (Asplenium scolopendrium). [ABSTRACT FROM AUTHOR]

The aim of this study is to determine the influence of lead on the species: Athyrium filix-femina (L.) Roth, Dryopteris filixmas (L.) Schott and D. affinis (Lowe) Fraser-Jenk. In order to reach this issue, we proposed the following objectives: the monitoring of the gametophyte differentiation on the soil that was contaminated with different lead concentrations and the estimation of the physiological status of the 3 species of fern in the initial development status (gametophyte and young sporophyte) through the analysis of the photosynthetic pigments and the determination of the antioxidant potential through the analysis of polyphenols. The variants tested were V1=0.1 g Pb2+, V2=0.2 g Pb2+, V3=0.5 g Pb2+, V4=1 g Pb2+and Control. Of the three species considered in the study, we have noticed, for the Athyrium filix-femina, the most advanced differentiation of the gametophyte. Low Pb concentrations: V1 and V2 stimulate the pigments content at A. filix-femina, respectively at Dryopteris filix-mas, and, of the pigments, the carotenoids have a protective role. A protective role against the stress produced by the heavy metal action is also possessed by the polyphenols, which usually tent to grow compared to the control, but without noticing significant differences. [ABSTRACT FROM AUTHOR]

The heavy metal lead is a persistent environmental pollutant. Our studies were carried out to evaluate physiological response and defensive potential of Asplenium scolopendrium exposed to different concentrations of lead added in soil as lead acetate. Plants were exposed to 0, 250, 500, 1000 and 1500 mg Kg-1 Pb+2 for 3 months. Plants possessed efficient enzymatic antioxidant defense mechanism that played important role in limiting stress. The physiological response of Asplenium scolopendrium was investigated by photosynthesis rate and assimilatory pigments (chlorophyll and carotenoids), while the antioxidant defense was evaluated by catalase activity. After 3 months of influencing, the photosynthesis rate is significantly inhibited by high concentration of lead (1500 mg Kg-1 Pb+2). Lower concentrations of lead not produced significant changes in the intensity of photosynthesis. Chlorophyll and carotenoid contents were not affected significantly by Pb treatment. The activity of catalase noted an increase with increasing amount of lead in the soil (an increase of 30.86% in V4 plants, in presence of 1500 mg Kg-1 Pb+2, compared to the control plants). [ABSTRACT FROM AUTHOR]

The aim of this research was to study the influence of compounds containing Ni and Cd on gametophyte differentiation in two native ferns, Dryopteris affinis Lowe Fraser Jenkins and D. filix mas L. Schott. The variants tested were V1Cd 3 mg L 1 Cd acetate, V2Cd 15 mg L 1 Cd acetate, V3Cd 30 mg L 1 Cd acetate, V1Ni 75 mg L 1 Ni sulphate, V2Ni 375 mg L 1 Ni sulphate, V3Ni 750 mg L 1 Ni sulphate and Control. The Pearson correlation index showed a significant negative correlation between the percentage of germinated spores and the heavy metal concentration in the culture medium, in both species. The main changes observed in the gametophyte were: a longer period needed to reach the characteristic stages, damage to rhizoid elongation, the formation of threedimensional cell masses, chlorosis and necrosis of the gametophyte cells, and accumulation of crystal structures on the surface of the gametophyte. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine the effect of chronic cadmium (Cd) action on the germination of spores and gametophyte differentiation in species Athyrium filix-femina (L.) Roth and Dryopteris filix-mas (L.) Schott, on different culture media (Knop solution, soil) for a period of 3 months. Cadmium was used in the following concentrations: C=0 mg Cd ∙ L-1 Knop solution/kg-1 soil, V1=25 mg Cd ∙ L-1 Knop solution/kg-1 soil, V2=50 mg Cd ∙ L-1 Knop solution/kg-1 soil, V3=100 mg Cd ∙ L-1 Knop solution/kg-1 soil, V4=150 mg Cd ∙ L-1 Knop solution/kg-1 soil. The percentage of germinated spores was found to decrease with the increasing Cd concentration in the environment, while germination is delayed in time. Unlike the Knop solution variants, in the soil variants gametophyte development was not significantly affected; for V1-2 soil concentrations the sporophyte appears in Athyrium filix-femina, a stage that was also noted for the Knop solution control, for the same species. In the case of the variants grown on Knop solution, although the spores did germinate and the gametophyte began to differentiate, Cd-induced chronic stress cannot be compensated by the gametophyte, so that the cells lose their membrane integrity, and their survival is compromised. [ABSTRACT FROM AUTHOR]